Showing posts with label VB.NET. Show all posts

.NET Programming for Absolute Beginners [Free Video Series]

Channel 9 has just launched an absolute beginner programming series to help people learn to program. This FREE training series is created for programmers who have no experience with C# or VB.NET

The series of 49 episodes (24 episodes for C# and 25 for VB.NET) walks you through fundamentals, getting the .NET tools, writing C# and VB.NET code, debugging features, customizations and much more to learn concepts applicable to video games, mobile environments, and client applications

You can access the series as well as read descriptions for each episode in the link given below:

Visual Basic Development for Absolute Beginners

C# Development for Absolute Beginners

Similarly you may also want to look at the Free Learning Resources section to access .NET training videos, articles, podcasts, ebooks and much more.

Remove all Lower Case Letters using C#

I came across a discussion where the OP wanted to use only the first letter of a word in a string. The first letter of each word was capitalized, so his requirement was to abbreviate the sentence by removing all lower case letters in a string.

For example: ‘We Love DevCurry.com’ would become ‘WLDC’

Here’s how this can be achieved with a Regular expression. Use the following code:

using System;
using System.Text.RegularExpressions;

namespace WordCapital
{
class Program
{
static void Main(string[] args)
{
string fulltext = "We Love DevCurry.com";
Console.WriteLine("Full Text: {0}", fulltext);
Regex rgx = new Regex("[^A-Z]");
Console.WriteLine("Abbreviated Text : {0}", 
rgx.Replace(fulltext, ""));
Console.ReadLine();
}
}
}

In the code above, we are using Regex to match all characters that are not capitalized and then replace it with an empty string.

OUTPUT

Use Anonymous Method with a Delegate in C#

A colleague of mine asked me a question - ‘How can we use an Anonymous method with a Delegate and when should we do it”.

By using anonymous methods, you reduce the coding overhead in instantiating delegates, by eliminating the need to create a separate method. You can use it to run code snippets that would otherwise require a named method or use it as a quick event-handler with no name.

Here’s the code that shows how to do it. Comments have been placed inline to understand the code

namespace ConsoleApplication2
{
// Define a Delegate
delegate int AddThenMultiply(int i, int j);

class Class1
{     
    static void Main(string[] args)
    {
        // Instatiate delegate type using anonymous method
        AddThenMultiply atm = delegate(int i, int j)
                            {
                                return (i + j) * 2;
                            };

        // Anonymous delegate call
        int result = atm(2, 3);
        Console.WriteLine("Result is: " + result);
        Console.ReadLine();
    }

}
}

OUTPUT

Determine if your Laptop is Running on battery using C# or VB.NET

Here’s some code to programmatically find out if your laptop is currently running on battery power. I have created a Windows Form application and added the following code on a button click event which uses the SystemInformation.PowerStatus property

private void btnPower_Click(object sender, EventArgs e)
{
   PowerLineStatus status = SystemInformation.PowerStatus.PowerLineStatus;
    if (status == PowerLineStatus.Offline)
        MessageBox.Show("Running on Battery");
    else
        MessageBox.Show("Running on Power");


}

VB.NET (Converted Code)

Private Sub btnPower_Click(ByVal sender As Object, ByVal e As EventArgs)
 Dim st As PowerLineStatus = SystemInformation.PowerStatus.PowerLineStatus
 If st = PowerLineStatus.Offline Then
     MessageBox.Show("Running on Battery")
 Else
     MessageBox.Show("Running on Power")
 End If

End Sub

Check Database connection using C# or VB.NET

As a programmer, one of the most common tasks in your application is to connect to the database. Here’s a very simple way to check your database connection before you start any task or use this as a service to check the connection and pause tasks if the connection breaks.

private static bool DBConnectionStatus()
{
    try
    {
        using (SqlConnection sqlConn =
            new SqlConnection("YourConnectionString"))
            {
                sqlConn.Open();
                return (sqlConn.State == ConnectionState.Open);
            }
    }
    catch (SqlException)
    {
        return false;
    }
    catch (Exception)
    {
        return false;
    }
}

VB.NET (Converted Code)

Private Function DBConnectionStatus() As Boolean
    Try
        Using sqlConn As New SqlConnection("YourConnectionString")
                sqlConn.Open()
                Return (sqlConn.State = ConnectionState.Open)
        End Using
    Catch e1 As SqlException
        Return False
    Catch e2 As Exception
        Return False
    End Try
End Function

The code above opens a connection to the database and returns a boolean depending on the database status.

Programmatically find CLR version for a .NET assembly

When it comes to extracting information from an assembly, Red Gate’s Reflector or the .NET Framework ILDASM tool are two obvious choices.

However if you have to programmatically determine the CLR version of an assembly it was compiled against, then use the Assembly.ImageRuntimeVersion property as shown below

Note: Add a namespace reference to System.Reflection

static void Main(string[] args)
{
    Assembly asmbly = null;
    asmbly = Assembly.ReflectionOnlyLoadFrom(@"C:/FckEdit/FredCK.FCKeditorV1.dll");
    Console.WriteLine("CLR version of 1st Assembly " + asmbly.ImageRuntimeVersion);
    asmbly = Assembly.ReflectionOnlyLoadFrom(@"C:/FckEdit/FredCK.FCKeditorV2.dll");
    Console.WriteLine("CLR version of 2nd Assembly " + asmbly.ImageRuntimeVersion);
    Console.ReadLine();
}

As you can see, we use ReflectionOnlyLoadFrom to load an assembly into reflection only context and then use the ImageRuntimeVersion property to get the version of the CLR saved in the assembly’s manifest.

OUTPUT

Convert DateTime to Different TimeZones

The TimeZoneInfo.ConvertTimeBySystemTimeZoneId in .NET 3.5 and 4.0, converts a time to the time in another time zone, based on a time zone identifier. Here’s how to use this method using different time zone identifiers like “India Standard Time”, “Pacific Standard Time” and so on:

static void Main(string[] args)
{
    DateTime dt = DateTime.Now;
    Console.WriteLine("Time in Different TimeZones:\n");

    Console.WriteLine("Indian Standard Time (IST): {0}",
                TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt,
                TimeZoneInfo.Local.Id, "India Standard Time"));
    Console.WriteLine("Eastern Standard Time (EST): {0}",
                TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt,
                TimeZoneInfo.Local.Id, "Eastern Standard Time"));
    Console.WriteLine("Pacific Standard Time (PST): {0}",
                TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt,
                TimeZoneInfo.Local.Id, "Pacific Standard Time"));
    Console.WriteLine("Greenwich Mean Time (GMT): {0}",
                TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt,
                TimeZoneInfo.Local.Id, "GMT Standard Time"));
    Console.ReadLine();
}

VB.NET (Converted Code)

Imports Microsoft.VisualBasic

Sub Main()
    Dim dt As Date = Date.Now
    Console.WriteLine("Time in Different TimeZones:" & vbLf)

    Console.WriteLine("Indian Standard Time (IST): {0}", TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt, TimeZoneInfo.Local.Id, "India Standard Time"))
    Console.WriteLine("Eastern Standard Time (EST): {0}", TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt, TimeZoneInfo.Local.Id, "Eastern Standard Time"))
    Console.WriteLine("Pacific Standard Time (PST): {0}", TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt, TimeZoneInfo.Local.Id, "Pacific Standard Time"))
    Console.WriteLine("Greenwich Mean Time (GMT): {0}", TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dt, TimeZoneInfo.Local.Id, "GMT Standard Time"))
    Console.ReadLine()
End Sub

OUTPUT

Programmatically Determine the Operating System using .NET

Here’s how to programmatically determine the Windows OS you are using. I will make use of the ManagementObjectSearcher class here

using System;
using System.Management;

namespace ConsoleApplication1
{
class Program
{
    public static void Main()
    {
        string winos = "Select Name from Win32_OperatingSystem";
        ManagementObjectSearcher mos =
            new ManagementObjectSearcher(winos);           
        foreach (ManagementObject mo in mos.Get())
        {
            Console.WriteLine("OS Name:  {0}", mo["Name"]);
        }
        Console.ReadLine();
    }
}
}

VB.NET

Imports System
Imports System.Management

Namespace ConsoleApplication1
Friend Class Program
    Public Shared Sub Main()
        Dim winos As String = "Select Name from Win32_OperatingSystem"
        Dim mos As New ManagementObjectSearcher(winos)
        For Each mo As ManagementObject In mos.Get()
            Console.WriteLine("OS Name:  {0}", mo("Name"))
        Next mo
        Console.ReadLine()
    End Sub
End Class
End Namespace

Here the Win32_OperatingSystem WMI class represents a Windows-based operating system installed on a computer.

OUTPUT

Detect if a String contains Special Characters

There are many ways to detect if a String contains Special Characters. In this code snippet, I will show a quick way to detect special characters using Regex.

static void Main(string[] args)
{
    string str = "Th!s $tri^g c@n$ist $pecial ch@rs";
    Match match = Regex.Match(str, "[^a-z0-9]",
            RegexOptions.IgnoreCase);
    while (match.Success)
    {
        string key = match.Value;
        Console.Write(key);
        match = match.NextMatch();
    }
    Console.ReadLine();
}

VB. NET

Shared Sub Main(ByVal args() As String)
    Dim str As String = "Th!s $tri^g c@n$ist $pecial ch@rs"
    Dim match As Match = Regex.Match(str, "[^a-z0-9]", _
RegexOptions.IgnoreCase)
    Do While match.Success
        Dim key As String = match.Value
        Console.Write(key)
        match = match.NextMatch()
    Loop
    Console.ReadLine()
End Sub

Regex.Match searches the input string for the first occurrence of the regular expression specified. The Success property of the Match object tells us whether the regular expression pattern has been found in the input string. If yes, then print the first match and retrieve subsequent matches by repeatedly calling the Match.NextMatch method.

OUTPUT

Random File Names using .NET

It helps to have knowledge of .NET classes. I was recently working on a requirement where some files were to be generated on the fly and stored on the disk. The requirement was that the files had to be generated with random characters and random extensions, to add extra security to the files. System.IO.Path.GetRandomFileName() returns a random folder name or file name which makes the task very simple, as shown below:

static void Main(string[] args)
{
    for (int i = 1; i < 10; i++)
        Console.WriteLine(System.IO.Path.GetRandomFileName());
    Console.ReadLine();
}

VB.NET

Shared Sub Main(ByVal args() As String)
    For i As Integer = 1 To 9
        Console.WriteLine(System.IO.Path.GetRandomFileName())
    Next i
    Console.ReadLine()
End Sub

Note: If you want to physically create some files on the disk, just pass these random names to a FileStream object inside the for loop. GetRandomFileName() does not create a physical file like GetTempFileName() does.

OUTPUT

Free C# and VB.NET Training Videos

When you are in the need of learning a new programming language or technology, a training video can do wonders! Here are some free C# and VB.NET Training Videos for both the novice and experienced.

So grab some popcorn this weekend, sit back and learn!

C# Training Videos

“How Do I?” Videos for Visual C#

C# Training on Google Videos

C# Training Videos on YouTube

MSDN C# On-Demand Webcast

Channel 9 C# Videos

VB.NET Training Videos

"How Do I" Videos — Visual Basic

VB.NET Training on Google Videos

VB.NET Training Videos on You Tube

MSDN Visual Basic On-Demand Webcasts

Channel 9 VB.NET Videos

Enum.TryParse in .NET 4.0

If you are using .NET 4.0, then Enum.TryParse<TEnum> is now provided out of the box and support flags enumeration. As given in the documentation, Enum.TryParse<> ‘Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object. The return value indicates whether the conversion succeeded.’

Here’s how to use it:

[Flags]
enum Result { Fail = 0, Pass = 1, Grace = 2 };

static void Main(string[] args)
{
    string a = (Result.Pass || Result.Grace).ToString();
    Result b;
    bool success = Enum.TryParse<Result>(a, out b);
    Console.WriteLine("{0} = {1}", success, b);
    Console.ReadLine();
}

OUTPUT

Concatenate Items of a List<String>

Here’s a simple way to concatenate items of a List<string>

static void Main(string[] args)
{
    List<string> strList = new List<string>()
    {
        "Jake", "Brian", "Raj", "Finnie", "Carol"
    };

    string str = string.Join(";", strList.ToArray());

    Console.WriteLine(str);
    Console.ReadLine();
}

VB.NET

Sub Main(ByVal args() As String)
    Dim strList As New List(Of String)() _
              From {"Jake", "Brian", "Raj", "Finnie", "Carol"}

    Dim str As String = string.Join(";", strList.ToArray())

    Console.WriteLine(str)
    Console.ReadLine()
End Sub

OUTPUT

Programmatically determine Total Free Space available on your Hard Drive

The DriveInfo.AvailableFreeSpace property indicates the amount of available free space on a drive. Here’s how to use this property to programmatically retrieve the total free space of all logical drives (including CD/DVD drives) on your machine.

static void Main(string[] args)
{
    foreach (DriveInfo drive in DriveInfo.GetDrives())
    {
        try
        {
            Console.WriteLine("{0} has {1} MB free space available",
            drive.RootDirectory, (drive.AvailableFreeSpace / 1024) / 1024);
        }
        catch (IOException io)
        {
            Console.WriteLine(io.Message);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }
    Console.ReadLine();
}

VB.NET

Shared Sub Main(ByVal args() As String)
    For Each drive As DriveInfo In DriveInfo.GetDrives()
        Try
            Console.WriteLine("{0} has {1} MB free space available", _
drive.RootDirectory, (drive.AvailableFreeSpace \ 1024) / 1024)
        Catch io As IOException
            Console.WriteLine(io.Message)
        Catch ex As Exception
            Console.WriteLine(ex.Message)
        End Try
    Next drive
    Console.ReadLine()
End Sub

OUTPUT

Detect an Empty String in .NET 4.0

In the previous versions of .NET, we used the String.IsNullOrEmpty method to find out whether the specified string is null or an Empty string. However this method did not tell us if the string contained only whitespaces. You had to use the Trim().Length method to detect that.

.NET 4.0 makes this simpler by introducing the String.IsNullOrWhiteSpace method to find out whether a specified string is null, empty, or consists only of white-space characters.

So the following piece of code

static void Main(string[] args)
{
    string str = new String(' ', 10);
    Console.WriteLine(String.IsNullOrWhiteSpace(str));
    Console.ReadLine();
}

will return True.

Generate Stronger Random Numbers using C# and VB.NET

The RNGCryptoServiceProvider Class implements a cryptographic Random Number Generator (RNG) using the implementation provided by the cryptographic service provider (CSP). Here’s how to generate random numbers using this class. Make sure you import the System.Security.Cryptography namespace before using this sample code

static void GenerateRandomNumber()
{
    byte[] byt = new byte[4];
    RNGCryptoServiceProvider rngCrypto =
        new RNGCryptoServiceProvider();
    rngCrypto.GetBytes(byt);
    int randomNumber = BitConverter.ToInt32(byt, 0);
    Console.WriteLine(randomNumber);
}

VB.NET

Shared Sub GenerateRandomNumber()
    Dim byt As Byte() = New Byte(4) {}
    Dim rngCrypto As New RNGCryptoServiceProvider()
    rngCrypto.GetBytes(byt)
    Dim randomNumber As Integer = BitConverter.ToInt32(byt, 0)
    Console.WriteLine(randomNumber)
End Sub

Programmatically determine if a Windows Service is running and stop it

The ServiceController class makes it easy to retrieve information about a windows service and manipulate it. Here’s some code. Before running this example, make sure you have added a reference to System.ServiceProcess

static void Main(string[] args)
{
    try
    {
       ServiceController controller = new ServiceController("SERVICENAME");

        if (controller.Status.Equals(ServiceControllerStatus.Running)
            && controller.CanStop)
        {
            controller.Stop();
            Console.WriteLine("Service Stopped");
        }         
        Console.ReadLine();
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
}

VB.NET

Shared Sub Main(ByVal args() As String)
    Try
        Dim controller As New ServiceController("SERVICENAME")

        If controller.Status.Equals(ServiceControllerStatus.Running)_

          AndAlso controller.CanStop Then
            controller.Stop()
            Console.WriteLine("Service Stopped")
        End If
        Console.ReadLine()
    Catch ex As Exception
        Console.WriteLine(ex.Message)
    End Try
End Sub

Make sure you have permission to stop the service or else you will get an exception.

Create Nested Directories in C# and VB.NET

A lot of developers do not know that Directory.CreateDirectory() can be used to create directories and subdirectories as specified by the path. Here’s an example

static void Main(string[] args)
{
    try
    {
        Directory.CreateDirectory(@"D:\ParentDir\ChildDir\SubChildDir\");
        Console.WriteLine("Directories Created");
        Console.ReadLine();
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
}

VB.NET

Shared Sub Main(ByVal args() As String)
    Try
        Directory.CreateDirectory("D:\ParentDir\ChildDir\SubChildDir\")
        Console.WriteLine("Directories Created")
        Console.ReadLine()
    Catch ex As Exception
        Console.WriteLine(ex.Message)
    End Try
End Sub

OUTPUT

C# 4.0 New Features, Videos, Articles and Books

I was collecting some learning material on C# 4.0 and stumbled across some useful videos, articles and documents available on C# 4.0. I am just listing a few of them. Check them out!

Please note that C# 4.0 is in Beta as of this writing.

Convert String to Base64 and Base64 to String

The System.Text.Encoding class provides methods to convert string to Base64 and vice versa

String to Base64

The conversion involves two processes:

a. Convert string to a byte array

b. Use the Convert.ToBase64String() method to convert the byte array to a Base64 string

byte[] byt = System.Text.Encoding.UTF8.GetBytes(strOriginal);
// convert the byte array to a Base64 string
strModified = Convert.ToBase64String(byt);

VB.NET

Dim byt As Byte() = System.Text.Encoding.UTF8.GetBytes(strOriginal)
' convert the byte array to a Base64 string
strModified = Convert.ToBase64String(byt)

Base64 string to Original String

In order to convert a Base64 string back to the original string, use FromBase64String(). The conversion involves two processes:

a. The FromBase64String() converts the string to a byte array

b. Use the relevant Encoding method to convert the byte array to a string, in our case UTF8.GetString();

byte[] b = Convert.FromBase64String(strModified);
strOriginal = System.Text.Encoding.UTF8.GetString(b);

VB.NET

Dim b As Byte() = Convert.FromBase64String(strModified)
strOriginal = System.Text.Encoding.UTF8.GetString(b)

Check out some additional String functions over here 30 Common String Operations in C# and VB.NET

.NET Programming for Absolute Beginners [Free Video Series]

Remove all Lower Case Letters using C#

Use Anonymous Method with a Delegate in C#

Determine if your Laptop is Running on battery using C# or VB.NET

Check Database connection using C# or VB.NET

Programmatically find CLR version for a .NET assembly

Convert DateTime to Different TimeZones

Programmatically Determine the Operating System using .NET

Detect if a String contains Special Characters

Random File Names using .NET

Free C# and VB.NET Training Videos

C# Training Videos

VB.NET Training Videos

Other Free Videos

Enum.TryParse in .NET 4.0

Concatenate Items of a List<String>

Programmatically determine Total Free Space available on your Hard Drive

Detect an Empty String in .NET 4.0

Generate Stronger Random Numbers using C# and VB.NET

Programmatically determine if a Windows Service is running and stop it

Create Nested Directories in C# and VB.NET

C# 4.0 New Features, Videos, Articles and Books

Samples and Documents

Articles

Books

Training Videos

Convert String to Base64 and Base64 to String

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