Fletcher Dunton

Issues with VS Orcas Beta 1 VPC and ASP.NET

Fletcher.Dunton — Mon, 20 Aug 2007 20:33:00 GMT

Like many folks have found, there are some issues to work out with VS Orcas Beta 1 VPC and ASP.NET:

Here's Rockford’s Blog, the first I found that clued my in to the problem of IIS 6.0 not being setup and enabled properly:

http://www.lhotka.net/WeBlog/SearchView.aspx?q=IIS

Here are a few on my own notes to help you going...

I. Enable IIS in Windows 2003 !!!!

Check and if need, Install Internet Information Services (IIS) 6.0:
Run Ad/Remove Programs:

Open the Windows Components Wizard.
Under Components, click Application Server, and then click Details.
In the Application Server dialog box, under Subcomponents of Application Server, click Internet Information Services (IIS), and then click Details.
In the Internet Information Services (IIS) dialog box, under Subcomponents of Internet Information Services (IIS), do either of the following:
To add optional components, select the check box next to the component that you want to install.
To remove optional components, clear the check box next to the component that you want to remove.
Click OK until you return to the Windows Component Wizard.
Verify that ASP.Net is checked and if not, check it and proceed with installation.Click Next, and then click Finish.

II. To verify that your IIS server is working correctly, use an Internet browser to view your Web page:

Responsible Managment of XML DOM's

Fletcher.Dunton — Fri, 08 Sep 2006 20:06:00 GMT

Folks: Since System.Xml.LoadXml(strXml) creats an in-memory instance of the System.Xml.XmlDocument you give it, memory usage could possibly become a factor and affect performance in a given application. Therefore, in the spirit of good coding practices, what is the responsibility of the developer when you are done with the XML DOM and want to free up memory? A. Invoke System.Xml.XmlDocument.RemoveAll() B. Use the Destructure Supplied with the XmlDocument...(read more)

Fix for Error 21002: [SQL-DMO] User already exists

Fletcher.Dunton — Fri, 08 Sep 2006 13:03:00 GMT

I cloned a database back from our DEV server to my local server and it had 1 user account called "webuser". That account had execute permissions on about 120 stored proc's. When I tried to create this user under my LOCAL Server's Security\Login folder, I got the following error: "Error 21002: [SQL-DMO] User 'webuser' already exists." So I went to my database\User folder and try and delete the account and it tells me "The Selected User Cannot be dropped b/c it owns objects". ...(read more)

Performance Test Tools for SQL 2000 ?

Fletcher.Dunton — Thu, 31 Aug 2006 15:51:00 GMT

A (long) while back I used a Microsoft's tool called "Database Hammer" to perform load testing on a database. It was implemented in VB 6 I believe and had a few limitations I wasn't happy with. My questions is, are there any newer, better tools out there shy of writing an a small test app each time? Any help is appreciated. Thank you.

Fletcher Dunton

MCAD, MCP

C# / VB.Net Syntax and Language Comparison

Fletcher.Dunton — Thu, 08 Jun 2006 01:29:00 GMT

VB.NET

Program Structure

Imports System

Namespace Hello
   Class HelloWorld
      Overloads Shared Sub Main(ByVal args() As String)
         Dim name As String = "VB.NET"

         'See if an argument was passed from the command line
         If args.Length = 1 Then name = args(0)

          Console.WriteLine("Hello, " & name & "!")
      End Sub
   End Class
End Namespace

using System;

namespace Hello {
   public class HelloWorld {
      public static void Main(string[] args) {
         string name = "C#";

         // See if an argument was passed from the command line
         if (args.Length == 1)
            name = args[0];

         Console.WriteLine("Hello, " + name + "!");
      }
   }
}

VB.NET

Comments

' Single line only
Rem Single line only

// Single line
/* Multiple
line */
/// XML comments on single line
/** XML comments on multiple lines */

VB.NET

Data Types

Value Types
Boolean
Byte
Char (example: "A"c)
Short, Integer, Long
Single, Double
Decimal
Date

Reference Types
Object
String

Dim x As Integer
Console.WriteLine(x.GetType()) ' Prints System.Int32
Console.WriteLine(GetType(Integer)) ' Prints System.Int32
Console.WriteLine(TypeName(x)) ' Prints Integer

' Type conversion
Dim d As Single = 3.5
Dim i As Integer = CType(d, Integer) ' set to 4 (Banker's rounding)
i = CInt(d) ' same result as CType
i = Int(d) ' set to 3 (Int function truncates the decimal)

Value Types
bool
byte, sbyte
char (example: 'A')
short, ushort, int, uint, long, ulong
float, double
decimal
DateTime (not a built-in C# type)

Reference Types
object
string

int x;
Console.WriteLine(x.GetType()); // Prints System.Int32
Console.WriteLine(typeof(int)); // Prints System.Int32
Console.WriteLine(x.GetType().Name); // prints Int32

// Type conversion
float d = 3.5f;
int i = (int)d; // set to 3 (truncates decimal)

VB.NET

Constants

Const MAX_STUDENTS As Integer = 25

' Can set to a const or var; may be initialized in a constructor
ReadOnly MIN_DIAMETER As Single = 4.93

const int MAX_STUDENTS = 25;

// Can set to a const or var; may be initialized in a constructor
readonly float MIN_DIAMETER = 4.93f;

VB.NET

Enumerations

Enum Action
Start
[Stop]   ' Stop is a reserved word
Rewind
Forward
End Enum

Enum Status
Flunk = 50
Pass = 70
Excel = 90
End Enum

Dim a As Action = Action.Stop
If a <> Action.Start Then _
Console.WriteLine(a.ToString & " is " & a)   ' Prints "Stop is 1"

Console.WriteLine(Status.Pass)    ' Prints 70
Console.WriteLine(Status.Pass.ToString())    ' Prints Pass

enum Action {Start, Stop, Rewind, Forward};
enum Status {Flunk = 50, Pass = 70, Excel = 90};

Action a = Action.Stop;
if (a != Action.Start)
Console.WriteLine(a + " is " + (int) a); // Prints "Stop is 1"

Console.WriteLine((int) Status.Pass); // Prints 70
Console.WriteLine(Status.Pass); // Prints Pass

VB.NET

Operators

Comparison
= < > <= >= <>

Arithmetic
+ - * /
Mod
\ (integer division)
^ (raise to a power)

Assignment
= += -= *= /= \= ^= <<= >>= &=

Bitwise
And Or Not << >>

Logical
AndAlso OrElse And Or Xor Not

Note: AndAlso and OrElse perform short-circuit logical evaluations

String Concatenation
& +

Comparison
== < > <= >= !=

Arithmetic
+ - * /
% (mod)
/ (integer division if both operands are ints)
Math.Pow(x, y)

Assignment
= += -= *= /= %= &= |= ^= <<= >>= ++ --

Bitwise
& | ^ ~ << >>

Logical
&& || & | ^ !

Note: && and || perform short-circuit logical evaluations

String Concatenation
+

VB.NET

Choices

greeting = IIf(age < 20, "What's up?", "Hello")

' One line doesn't require "End If"
If age < 20 Then greeting = "What's up?"
If age < 20 Then greeting = "What's up?" Else greeting = "Hello"

' Use : to put two commands on same line
If x <> 100 And y < 5 Then x *= 5 : y *= 2

' Preferred
If x <> 100 And y < 5 Then
x *= 5
y *= 2
End If

' To break up any long single line use _
If whenYouHaveAReally < longLine And _
itNeedsToBeBrokenInto2 > Lines Then _
UseTheUnderscore(charToBreakItUp)

'If x > 5 Then
x *= y
ElseIf x = 5 Then
x += y
ElseIf x < 10 Then
x -= y
Else
x /= y
End If

Select Case color   ' Must be a primitive data type
Case "pink", "red"
    r += 1
Case "blue"
    b += 1
Case "green"
    g += 1
Case Else
    other += 1
End Select

greeting = age < 20 ? "What's up?" : "Hello";

if (age < 20)
greeting = "What's up?";
else
greeting = "Hello";

// Multiple statements must be enclosed in {}
if (x != 100 && y < 5) {
x *= 5;
y *= 2;
}

No need for _ or : since ; is used to terminate each statement.

if (x > 5)
x *= y;
else if (x == 5)
x += y;
else if (x < 10)
x -= y;
else
x /= y;

// Every case must end with break or goto case
switch (color) {                          // Must be integer or string
case "pink":
case "red":    r++;    break;
case "blue":   b++;   break;
case "green": g++;   break;
default:    other++;   break;       // break necessary on default
}

VB.NET

Loops

Pre-test Loops:
While c < 10 c += 1 End While	Do Until c = 10 c += 1 Loop
Do While c < 10 c += 1 Loop	For c = 2 To 10 Step 2 Console.WriteLine(c) Next
Post-test Loops:
Do c += 1 Loop While c < 10	Do c += 1 Loop Until c = 10

' Array or collection looping
Dim names As String() = {"Fred", "Sue", "Barney"}
For Each s As String In names
Console.WriteLine(s)
Next

' Breaking out of loops
Dim i As Integer = 0
While (True)
If (i = 5) Then Exit While
i += 1
End While

' Continue to next iteration
For i = 0 To 4
If i < 4 Then Continue For
Console.WriteLine(i) ' Only prints 4
Next

Pre-test Loops:

// no "until" keyword
while (c < 10)
c++;

for (c = 2; c <= 10; c += 2)
Console.WriteLine(c);

Post-test Loop:

do
c++;
while (c < 10);

// Array or collection looping
string[] names = {"Fred", "Sue", "Barney"};
foreach (string s in names)
Console.WriteLine(s);

// Breaking out of loops
int i = 0;
while (true) {
if (i == 5)
break;
i++;
}

// Continue to next iteration
for (i = 0; i < 5; i++) {
if (i < 4)
continue;
Console.WriteLine(i); // Only prints 4
}

VB.NET

Arrays

Dim nums() As Integer = {1, 2, 3}
For i As Integer = 0 To nums.Length - 1
Console.WriteLine(nums(i))
Next

' 4 is the index of the last element, so it holds 5 elements
Dim names(4) As String
names(0) = "David"
names(5) = "Bobby" ' Throws System.IndexOutOfRangeException

' Resize the array, keeping the existing values (Preserve is optional)
ReDim Preserve names(6)

Dim twoD(rows-1, cols-1) As Single
twoD(2, 0) = 4.5

Dim jagged()() As Integer = { _
New Integer(4) {}, New Integer(1) {}, New Integer(2) {} }
jagged(0)(4) = 5

int[] nums = {1, 2, 3};
for (int i = 0; i < nums.Length; i++)
Console.WriteLine(nums[i]);

// 5 is the size of the array
string[] names = new string[5];
names[0] = "David";
names[5] = "Bobby"; // Throws System.IndexOutOfRangeException

// C# can't dynamically resize an array. Just copy into new array.
string[] names2 = new string[7];
Array.Copy(names, names2, names.Length); // or names.CopyTo(names2, 0);

float[,] twoD = new float[rows, cols];
twoD[2,0] = 4.5f;

int[][] jagged = new int[3][] {
new int[5], new int[2], new int[3] };
jagged[0][4] = 5;

VB.NET

Functions

' Pass by value (in, default), reference (in/out), and reference (out)
Sub TestFunc(ByVal x As Integer, ByRef y As Integer, ByRef z As Integer)
x += 1
y += 1
z = 5
End Sub

Dim a = 1, b = 1, c As Integer ' c set to zero by default
TestFunc(a, b, c)
Console.WriteLine("{0} {1} {2}", a, b, c) ' 1 2 5

' Accept variable number of arguments
Function Sum(ByVal ParamArray nums As Integer()) As Integer
Sum = 0
For Each i As Integer In nums
    Sum += i
Next
End Function   ' Or use Return statement like C#

Dim total As Integer = Sum(4, 3, 2, 1)   ' returns 10

' Optional parameters must be listed last and must have a default value
Sub SayHello(ByVal name As String, Optional ByVal prefix As String = "")
Console.WriteLine("Greetings, " & prefix & " " & name)
End Sub

SayHello("Strangelove", "Dr.")
SayHello("Madonna")

// Pass by value (in, default), reference (in/out), and reference (out)
void TestFunc(int x, ref int y, out int z) {
x++;
y++;
z = 5;
}

int a = 1, b = 1, c; // c doesn't need initializing
TestFunc(a, ref b, out c);
Console.WriteLine("{0} {1} {2}", a, b, c); // 1 2 5

// Accept variable number of arguments
int Sum(params int[] nums) {
int sum = 0;
foreach (int i in nums)
sum += i;
return sum;
}

int total = Sum(4, 3, 2, 1); // returns 10

/* C# doesn't support optional arguments/parameters. Just create two different versions of the same function. */
void SayHello(string name, string prefix) {
Console.WriteLine("Greetings, " + prefix + " " + name);
}

void SayHello(string name) {
SayHello(name, "");
}

VB.NET

Strings

Special character constants
vbCrLf, vbCr, vbLf, vbNewLine
vbNullString
vbTab
vbBack
vbFormFeed
vbVerticalTab
""

' String concatenation (use & or +)
Dim school As String = "Harding" & vbTab
school = school & "University" ' school is "Harding (tab) University"

' Chars
Dim letter As Char = school.Chars(0)   ' letter is H
letter = Convert.ToChar(65)               ' letter is A
letter = Chr(65)                                 ' same thing
Dim word() As Char = school.ToCharArray() ' word holds Harding

' No string literal operator
Dim msg As String = "File is c:\temp\x.dat"

' String comparison
Dim mascot As String = "Bisons"
If (mascot = "Bisons") Then ' true
If (mascot.Equals("Bisons")) Then ' true
If (mascot.ToUpper().Equals("BISONS")) Then ' true
If (mascot.CompareTo("Bisons") = 0) Then ' true

Console.WriteLine(mascot.Substring(2, 3)) ' Prints "son"

' String matching
If ("John 3:16" Like "Jo[Hh]? #:*") Then 'true

Imports System.Text.RegularExpressions ' More powerful than Like
Dim r As New Regex("Jo[hH]. \d:*")
If (r.Match("John 3:16").Success) Then 'true

' My birthday: Oct 12, 1973
Dim dt As New DateTime(1973, 10, 12)
Dim s As String = "My birthday: " & dt.ToString("MMM dd, yyyy")

' Mutable string
Dim buffer As New System.Text.StringBuilder("two ")
buffer.Append("three ")
buffer.Insert(0, "one ")
buffer.Replace("two", "TWO")
Console.WriteLine(buffer) ' Prints "one TWO three"

Escape sequences
\n, \r
\t
\\
\"

// String concatenation
string school = "Harding\t";
school = school + "University"; // school is "Harding (tab) University"

// Chars
char letter = school[0];           // letter is H
letter = Convert.ToChar(65); // letter is A
letter = (char)65;                    // same thing
char[] word = school.ToCharArray();   // word holds Harding

// String literal
string msg = @"File is c:\temp\x.dat";
// same as
string msg = "File is c:\\temp\\x.dat";

// String comparison
string mascot = "Bisons";
if (mascot == "Bisons") // true
if (mascot.Equals("Bisons")) // true
if (mascot.ToUpper().Equals("BISONS")) // true
if (mascot.CompareTo("Bisons") == 0) // true

Console.WriteLine(mascot.Substring(2, 3)); // Prints "son"

// String matching
// No Like equivalent - use regular expressions

using System.Text.RegularExpressions;
Regex r = new Regex(@"Jo[hH]. \d:*");
if (r.Match("John 3:16").Success) // true

// My birthday: Oct 12, 1973
DateTime dt = new DateTime(1973, 10, 12);
string s = "My birthday: " + dt.ToString("MMM dd, yyyy");

// Mutable string
System.Text.StringBuilder buffer = new System.Text.StringBuilder("two ");
buffer.Append("three ");
buffer.Insert(0, "one ");
buffer.Replace("two", "TWO");
Console.WriteLine(buffer); // Prints "one TWO three"

VB.NET

Exception Handling

' Throw an exception
Dim ex As New Exception("Something is really wrong.")
Throw ex

' Catch an exception
Try
y = 0
x = 10 / y
Catch ex As Exception When y = 0 ' Argument and When is optional
Console.WriteLine(ex.Message)
Finally
Beep()
End Try

' Deprecated unstructured error handling
On Error GoTo MyErrorHandler
...
MyErrorHandler: Console.WriteLine(Err.Description)

// Throw an exception
Exception up = new Exception("Something is really wrong.");
throw up; // ha ha

// Catch an exception
try {
y = 0;
x = 10 / y;
}
catch (Exception ex) { // Argument is optional, no "When" keyword
Console.WriteLine(ex.Message);
}
finally {
// Requires reference to the Microsoft.VisualBasic.dll
// assembly (pre .NET Framework v2.0)
Microsoft.VisualBasic.Interaction.Beep();
}

VB.NET

Namespaces

Namespace Harding.Compsci.Graphics
...
End Namespace

' or

Namespace Harding
Namespace Compsci
    Namespace Graphics
      ...
    End Namespace
End Namespace
End Namespace

Imports Harding.Compsci.Graphics

namespace Harding.Compsci.Graphics {
...
}

// or

namespace Harding {
namespace Compsci {
    namespace Graphics {
      ...
    }
}
}

using Harding.Compsci.Graphics;

VB.NET

Classes / Interfaces

Accessibility keywords
Public
Private
Friend
Protected
Protected Friend
Shared

' Inheritance
Class FootballGame
Inherits Competition
...
End Class

' Interface definition
Interface IAlarmClock
...
End Interface

// Extending an interface
Interface IAlarmClock
Inherits IClock
...
End Interface

// Interface implementation
Class WristWatch
Implements IAlarmClock, ITimer
...
End Class

Accessibility keywords
public
private
internal
protected
protected internal
static

// Inheritance
class FootballGame : Competition {
...
}

// Interface definition
interface IAlarmClock {
...
}

// Extending an interface
interface IAlarmClock : IClock {
...
}

// Interface implementation
class WristWatch : IAlarmClock, ITimer {
...
}

VB.NET

Constructors / Destructors

Class SuperHero
Private _powerLevel As Integer

Public Sub New()
    _powerLevel = 0
End Sub

Public Sub New(ByVal powerLevel As Integer)
    Me._powerLevel = powerLevel
End Sub

Protected Overrides Sub Finalize()
   ' Desctructor code to free unmanaged resources
    MyBase.Finalize()
End Sub
End Class

class SuperHero {
private int _powerLevel;

public SuperHero() {
     _powerLevel = 0;
}

public SuperHero(int powerLevel) {
    this._powerLevel= powerLevel;
}

~SuperHero() {
    // Destructor code to free unmanaged resources.
    // Implicitly creates a Finalize method
}
}

VB.NET

Using Objects

Dim hero As SuperHero = New SuperHero
' or
Dim hero As New SuperHero

With hero
.Name = "SpamMan"
.PowerLevel = 3
End With

hero.Defend("Laura Jones")
hero.Rest() ' Calling Shared method
' or
SuperHero.Rest()

Dim hero2 As SuperHero = hero ' Both reference the same object
hero2.Name = "WormWoman"
Console.WriteLine(hero.Name) ' Prints WormWoman

hero = Nothing ' Free the object

If hero Is Nothing Then _
hero = New SuperHero

Dim obj As Object = New SuperHero
If TypeOf obj Is SuperHero Then _
Console.WriteLine("Is a SuperHero object.")

' Mark object for quick disposal
Using reader As StreamReader = File.OpenText("test.txt")
Dim line As String = reader.ReadLine()
While Not line Is Nothing
Console.WriteLine(line)
line = reader.ReadLine()
End While
End Using

SuperHero hero = new SuperHero();

// No "With" construct
hero.Name = "SpamMan";
hero.PowerLevel = 3;

hero.Defend("Laura Jones");
SuperHero.Rest(); // Calling static method

SuperHero hero2 = hero; // Both reference the same object
hero2.Name = "WormWoman";
Console.WriteLine(hero.Name); // Prints WormWoman

hero = null ; // Free the object

if (hero == null)
hero = new SuperHero();

Object obj = new SuperHero();
if (obj is SuperHero)
Console.WriteLine("Is a SuperHero object.");

// Mark object for quick disposal
using (StreamReader reader = File.OpenText("test.txt")) {
string line;
while ((line = reader.ReadLine()) != null)
Console.WriteLine(line);
}

VB.NET

Structs

Structure StudentRecord
Public name As String
Public gpa As Single

Public Sub New(ByVal name As String, ByVal gpa As Single)
Me.name = name
Me.gpa = gpa
End Sub
End Structure

Dim stu As StudentRecord = New StudentRecord("Bob", 3.5)
Dim stu2 As StudentRecord = stu

stu2.name = "Sue"
Console.WriteLine(stu.name) ' Prints Bob
Console.WriteLine(stu2.name) ' Prints Sue

struct StudentRecord {
public string name;
public float gpa;

public StudentRecord(string name, float gpa) {
this.name = name;
this.gpa = gpa;
}
}

StudentRecord stu = new StudentRecord("Bob", 3.5f);
StudentRecord stu2 = stu;

stu2.name = "Sue";
Console.WriteLine(stu.name);    // Prints Bob
Console.WriteLine(stu2.name);   // Prints Sue

VB.NET

Properties

Private _size As Integer

Public Property Size() As Integer
Get
   Return _size
End Get
Set (ByVal Value As Integer)
    If Value < 0 Then
      _size = 0
    Else
      _size = Value
    End If
End Set
End Property

foo.Size += 1

private int _size;

public int Size {
get {
return _size;
}
set {
if (value < 0)
_size = 0;
else
_size = value;
}
}

foo.Size++;

VB.NET

Delegates / Events

Delegate Sub MsgArrivedEventHandler(ByVal message As String)

Event MsgArrivedEvent As MsgArrivedEventHandler

' or to define an event which declares a delegate implicitly
Event MsgArrivedEvent(ByVal message As String)

AddHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback
' Won't throw an exception if obj is Nothing
RaiseEvent MsgArrivedEvent("Test message")
RemoveHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback

Imports System.Windows.Forms

Dim WithEvents MyButton As Button ' WithEvents can't be used on local variable
MyButton = New Button

Private Sub MyButton_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyButton.Click
MessageBox.Show(Me, "Button was clicked", "Info", _
MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub

delegate void MsgArrivedEventHandler(string message);

event MsgArrivedEventHandler MsgArrivedEvent;

// Delegates must be used with events in C#

MsgArrivedEvent += new MsgArrivedEventHandler(My_MsgArrivedEventCallback);
MsgArrivedEvent("Test message"); // Throws exception if obj is null
MsgArrivedEvent -= new MsgArrivedEventHandler(My_MsgArrivedEventCallback);

using System.Windows.Forms;

Button MyButton = new Button();
MyButton.Click += new System.EventHandler(MyButton_Click);

private void MyButton_Click(object sender, System.EventArgs e) {
MessageBox.Show(this, "Button was clicked", "Info",
MessageBoxButtons.OK, MessageBoxIcon.Information);
}

VB.NET

Console I/O

Console.Write("What's your name? ")
Dim name As String = Console.ReadLine()
Console.Write("How old are you? ")
Dim age As Integer = Val(Console.ReadLine())
Console.WriteLine("{0} is {1} years old.", name, age)
' or
Console.WriteLine(name & " is " & age & " years old.")

Dim c As Integer
c = Console.Read() ' Read single char
Console.WriteLine(c) ' Prints 65 if user enters "A"

Console.Write("What's your name? ");
string name = Console.ReadLine();
Console.Write("How old are you? ");
int age = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("{0} is {1} years old.", name, age);
// or
Console.WriteLine(name + " is " + age + " years old.");

int c = Console.Read(); // Read single char
Console.WriteLine(c); // Prints 65 if user enters "A"

VB.NET

File I/O

Imports System.IO

' Write out to text file
Dim writer As StreamWriter = File.CreateText("c:\myfile.txt")
writer.WriteLine("Out to file.")
writer.Close()

' Read all lines from text file
Dim reader As StreamReader = File.OpenText("c:\myfile.txt")
Dim line As String = reader.ReadLine()
While Not line Is Nothing
Console.WriteLine(line)
line = reader.ReadLine()
End While
reader.Close()

' Write out to binary file
Dim str As String = "Text data"
Dim num As Integer = 123
Dim binWriter As New BinaryWriter(File.OpenWrite("c:\myfile.dat"))
binWriter.Write(str)
binWriter.Write(num)
binWriter.Close()

' Read from binary file
Dim binReader As New BinaryReader(File.OpenRead("c:\myfile.dat"))
str = binReader.ReadString()
num = binReader.ReadInt32()
binReader.Close()

using System.IO;

// Write out to text file
StreamWriter writer = File.CreateText("c:\\myfile.txt");
writer.WriteLine("Out to file.");
writer.Close();

// Read all lines from text file
StreamReader reader = File.OpenText("c:\\myfile.txt");
string line = reader.ReadLine();
while (line != null) {
Console.WriteLine(line);
line = reader.ReadLine();
}
reader.Close();

// Write out to binary file
string str = "Text data";
int num = 123;
BinaryWriter binWriter = new BinaryWriter(File.OpenWrite("c:\\myfile.dat"));
binWriter.Write(str);
binWriter.Write(num);
binWriter.Close();

// Read from binary file
BinaryReader binReader = new BinaryReader(File.OpenRead("c:\\myfile.dat"));
str = binReader.ReadString();
num = binReader.ReadInt32();
binReader.Close();

From Frank McCowan's page at http://www.harding.edu/USER/fmccown/WWW/vbnet_csharp_comparison.html , I'm doing a refresher on the lanaguage constructs and differences between C# and VB.Net:

This work is licensed under a Creative Commons License.

Book Review: Applying UML and Patterns by Craig Larman

Fletcher.Dunton — Tue, 06 Jun 2006 03:40:00 GMT

I picked this book up several years ago while writing curriculum for a training class on OOAD and UML. My reason for seeking it was that I needed an alternative to several of the books that Rational published, including UML Distilled and The Unified Modeling Language User Guide. The later two texts just did not tie UML, process and practical examples together and Larman's book did.

What appealed to me about "Applying UML and Patterns", is that it combined both theory and practice in manifold ways. I’ve critiqued each of the following areas:

Software Development Life Cycle
UML
Patterns
Practical Case Study and Examples

Software Development Life Cycle - From project Inception through Elaboration, even one new to the Unified Process will know exactly where the sample project is within the software development life cycle. In addition, the book gives the reader both a good intro to the Agile UP and substantiates why UP driven projects have higher success rates than those using the waterfall process. It sites the MIT Sloan Management Review of Successful Projects (http://smr.mit.edu) to build the case.

UML and other Artifacts - The book does an outstanding job of giving solid examples of applying UML notation and creating Use Cases. From writing effective use cases, to creating and refining a domain object model, to applying several popular patterns, you'll be glued each chapter. The inside and back cover provide useful aides for quick reference to the UP, several of Larman's patterns and UML notation.

Patterns - I think the book's value in showing how patterns compliment the design process speaks for itself. Those introduced, such as Larman's "Information Expert", "Creator" and "Controller" are part of his GRASP series.

Practical Case Study and Examples - The book intertwines UML, UP and a realistic case project called the “NextGEN point of sale system” in a real, practical way. Often, I've loaned this book to colleagues and client managers, both for their edification and at times to persuade them on a finer point of RUP, Agile and UP based process. It has also proved to be a good reference by providing RUP objectives and UML artifacts at key points in the SDLC.

Overall, the book makes for good reading for developers and team leads alike. I recommend it as a baseline prior to choosing a UP based methodology and for those wanting to understand the big picture and how Use Case, UML, Patterns and UP can compliment on another.

It would be great to see a book as quality as this written using .Net specific tools, such as Visio UML and C#.

If you are interested, please see www.craiglarman.com for more details and sample chapter from the book.

Application Error Handling in ASP.Net

Fletcher.Dunton — Tue, 06 Jun 2006 03:37:00 GMT

In trying to standardize Application Error Handling, my group has come up with the following guidelines. Feel free to pick it apart and provide your comments back to me.

Each application should implement error handling in the following order :
1. Try-Catch - Use of Structured Exception Handling blocks
2. Use of Page Level Error Events
3. Application Wide Error Pages
4. Exceptions shall be logged
5. Using and Enabling Trace

Every effort should be made by the developer to provide structured exception handling blocks to circumvent un-handled exceptions. Therefore, Page Level and Application Wide error trapping should be used to augment SEH, but not circumvent it.

Structured Exception Handling Blocks:

The use of Try...Catch...Finally Statements will be used as a first attempt to trap and correct application errors. Try…Catch…Finally statements should be placed around related blocks of code at a granularity that facilitates catching and correcting errors with minimal impact to the end user. The following general form shall be used:

Try

[ tryStatements ]

[ Catch [ exception [ As type ] ]

[ catchStatements ] ]

[ Exit Try ]

...

[ Finally

[ finallyStatement ] ]

End Try

Page Level Error Events:
The Page object’s ErrorPage attribute shall be used display a specific page when an unhandled exception occurs on a Web form. The page-level setting supersedes the application-level settings in the Web.config file.

For example, the following HTML sets the ErrorPage attribute for a Web form:

Inherits="MCSDWebAppsVB.ErrorPages" errorPage="ErrDefault.aspx"%>When the exception occurs, the user is redirected to designated error page (i.e.ErrDefault.aspx). Because the error page is displayed through redirection, the context for the error is lost and Server.GetLastError returns nothing from the target error page. Therefore, Server.GetLastError shall be called in the Page_Error event and the result placed in a Session variable.

Application Wide Error Pages:
Application Wide Error Pages shall be used to provide user friendly responses for errors not caught in a structured event handling block. The customErrors section of the web.config file shall be set to specify a default error page to display, along with other required error pages for specific HTTP response codes that indicate errors.
For example:

o The customErrors mode attribute must equal On to view the error pages while debugging the application on your local machine.
o Setting the mode to RemoteOnly (the default) will display the designated error pages when the application is accessed from client computers, but not when the application is accessed locally.

Logging Exceptions:
Any exceptions that meet the following criteria should be logged:
o Those considered serious in that they could result in data loss or corruption
o Those that need to be monitored for application:
o Security
o Performance
o Functional Compliance

Using the System.Diagnostics namespace, exceptions shall be logged either to the Server “Application” or Log. The following approach, should be used:

Dim eventLog1 As New EventLog()
If Not eventLog1.SourceExists("") Then
eventLog1.CreateEventSource("", "< ApplicationName>")
End If
eventLog1.Source = "(")
eventLog1.WriteEntry("", ex.ToString(), _
EventLogEntryType.Error)
eventLog1 = Nothing

Using and Enabling Trace:
Tracing is an integral and useful part of application development within the .Net Framework while debugging, testing and even at times, in production. The following convention will ensure that it is used properly in each SDLC phase.

During Development:
It shall be the developer’s responsibility to use the Shared (static) methods of the Trace Class, which is part of System.Diagnostics namespace:
o Write - Writes to Listeners collection
o WriteLine - Same as Write except adds a CR to the end
o WriteIf - Writes conditionally
o WriteLineIf - Same as WriteIf except adds a CR to the end
o Assert - Writes to listeners collection if expression is False and displays a message box
o Fail - Same as Assert except condition automatically fails without testing
o Trace levels shall be used so that the granularity of trace information can be controlled.
o Output shall be sent to the appropriate Listeners collection. If the TextWriterTraceListener is used, care shall be taken to ensure the log file is created new each session, so that it does not become excessively large.
o The Trace class shall be used over the Debug class. Since the only difference between Trace and Debug is that Debug statements are not included in Release version, the Trace class shall be used over the Debug class. This will ensure tracing can be enabled in production.

During System Test and Production:
For security reasons, it shall be the developer’s and admin’s responsibility to ensure that tracing is disabled when an active debug session in not in process.

As tracing can be turned controlled for an entire Web application or for an individual page in the application and the following standard ASP.Net conventions should be used:
o In order to access the Trace.axd page, turn tracing on for an entire application in the application’s Web.config file, set the element’s Enabled attribute to True.
o Other Trace Attributes should be responsibly managed by the developer and team as illustrated:

o where pageOutput="false" writes to the Trace.axd log file, else it will to screen.
o requestLimit="N“ so the only the first N requests go to Trace.axd.
o localOnly="true“ should be used to ensure that trace is only viewed by the local IIS developer or admin, but not remotely by the user community.
o To configure trace level in web.config set the relevant via XML Key/Value Pairs. For example:

Single Page Tracing shall be used judiciously during production. If need, to turn tracing on for a single page, the DOCUMENT object’s Trace property can be set to True in the Visual Studio .NET Properties window. This sets the @ Page directive’s Trace attribute to True in the Web form’s HTML.

***

ASP.NET: Best Practices and Techniques for Building Secure ASP.NET Applications

Fletcher.Dunton — Thu, 05 Feb 2004 11:29:00 GMT

Folks: I just signed up to attend a MSDN session on ASP.NET: Best Practices and Techniques for Building Secure ASP.NET Applications to held next week in my area. Has anyone attended? And if so, is it worth the while. For example, how much it tech content vs. high level, marketing? Advise.

See http://launch3.popgram.com/Launch.aspx?BID=1802728236&bhcp=1 for more detials.

RFI: C# and VB.Net Code Standards and related SLDC guidelines

Fletcher.Dunton — Tue, 03 Feb 2004 15:55:00 GMT

Folks: It's been on my list for while, to solicit a request for information for any known groups that are currently collaborating and publishing a concise set of code and peer review standards use with .Net CLS languages. I'm contemplating starting an initiative in this direction. Perhaps a better use of my effort would be to join one that already has some momentum and direction. Please reply back for any advice or knowledge of current efforts in the industry. Thanks and Best Regards to all. Fletcher Dunton

"IIS Not Running ASP.Net 1.1"

Fletcher.Dunton — Wed, 14 Jan 2004 10:35:00 GMT

Folks:

Recently, a student of mine installed VS.Net 2003 on their XP Pro box, then eagerly started developing a new ASP.Net web app and received the message:

"Visual Studio .Net has detected that the specified Web Server is not Running ASP.Net 1.1”.

Initially, I questioned how that could happen, since VS.Net 2003 comes with the 1.1 framework. Then after some investigation (but without rebuilding my PC to verify this) I've come up with the following scenario that might make cause the problem:

I developer installed XP Pro (or Server 2003) and does not explicitly set the IIS option at install time.
They then install VS.Net 2003, which installs the 1.1 framework.
They try to create a ASP.Net web app and receive a nasty gram to the effect “http :Internal Server error, server not found“.
Realizing that IIS is not on there PC, they pull the OS install disk out and run setup, installing the web server.
This installs the 1.0 framework on the box, but does not configure the web server and ASP.net for side by side execution of the framework.

Luckily, there's a fix:

If this has happened to you, you may need to run aspnet_regiis with the -r option to replace the current version of IIS and script maps.
If this has happened to you and you DON'T need side by side execution of the framework., please download the 1.1 framework follow the instruction documented at : http://www.asp.net/download-1.1.aspx?tabindex=0&tabid=1
If this has happened to you and you need side by side execution of the framework., please see: http://www.asp.net/faq/SideBySide.aspx

I welcome your feedback...

Series:Axioms for Good IT Process

Fletcher.Dunton — Tue, 13 Jan 2004 12:24:00 GMT

I was recently asked by a client to help them evaluate their current IT process. As I browsed their existing policy, project notebooks and other artifacts I came to realize just how deceived and misinformed (these) folks were about what “good IT process“ is and is not.

In fact, some of the comments I received back from both management and developers ranged from “I just hate (any) process” to “Should I go to CMM training?” (I just love that one) and “We can't afford to have a process.“ (well “boo-hoo-hoo”). And these were highly paid professionals.

Look, we've all had the displeasure of working on projects that have no requirements, plan or direction. And conversely, many of us have worked for shops that have so much process that one must fill out a leave slip just to take a break for a call to nature! To the extreme, each of these environments are highly ineffective and introduces risk ($$$), both to the system under development and our collective livelihood. Surely, there has to middle ground. There must be way.

Ah-hah: I see I’ve piqued your interest. Over the next few weeks, I’ll be expanding on “Axioms for Good IT process”, including the following

1. “Its not that you have a process, rather it’s what process you have.”

2. “People are more important than any process.” - Grady Booch

3. “Good people with a good process will outperform good people with no process every time.” - Grady Booch

4. It’s not that you can’t afford to have a process, it’s that you can’t afford NOT to have GOOD process.

5. Eventually, the Sarbanes-Oxley Act (http://www.sarbanes-oxley.com) will affect you and your IT Shop and the integrity with which each project’s artifacts are maintained.

Listen, your process is not static. It must evolve over time. And it is a living reflection of you and your firm.

I welcome your feedback. By the way, you know that Mom and Pop Shop that just opened down the street? Well they're CMM Level 5.

Welcome and Thanks!

Fletcher.Dunton — Sat, 23 Aug 2003 10:07:00 GMT

Welcome and Thanks!

Folks:

Welcome to my DNJ Blog and thanks VERY much to the good folks at DotNetJunkies for such an outstanding .Net forum:

And to Mark Digiovanni, my work colleague and Ace Developer at-large for turning me on to this. And to the current “Top Bloginator”, Darrell Norton who turned Mark D onto blogging at DNJ.

It’s been a pleasure getting to know these guys and some other extremely sharp talent, through the local .Net User Group ( www.WeProgram.net ), academic affiliations ( www.Odu.edu/ItPro ) and Work (www.Keane.com).

I’ve really been contemplating starting a weblog for awhile, as means to express and share the depth of my geek·ti·tudeness, so I’m very happy to be here : ).

Thanks again,

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