You can write multithreaded
applications in Microsoft Visual C# .NET or in Microsoft Visual C#. This article describes how a simple Visual C# application
can create and manage threads.
Back to the top
Requirements
The following list outlines the recommended hardware, software,
network infrastructure, and service packs that you need:
| • | Microsoft Windows 2000, Microsoft Windows XP, or Microsoft Windows Server 2003 |
| • | Microsoft Visual C# .NET or Microsoft Visual C# 2005 |
This article assumes that you are familiar with the following
topics:
| • | Visual C# programming |
| • | Visual Studio .NET Integrated Development Environment
(IDE) or Visual Studio 2005 IDE |
Back to the top
Create a Visual C# application with threads
| 1. | Start Microsoft Visual Studio .NET, Microsoft Visual Studio 2005, or Microsoft Visual C# 2005 Express Edition. |
| 2. | Create a new Visual C# Windows Application project
named ThreadWinApp. |
| 3. | Add a Button control to the form. By
default, the button is named Button1. |
| 4. | Add a ProgressBar component to the form.
By default, the progress bar is named ProgressBar1. |
| 5. | Right-click the form, and then click View
Code. |
| 6. | Add the following statement to the beginning of the file:using System.Threading; |
| 7. | Add the following Click event handler for
Button1:private void button1_Click(object sender, System.EventArgs e)
{
MessageBox.Show("This is the main thread");
} |
| 8. | Add the following variable to the Form1 class:private Thread trd;
|
| 9. | Add the following method to the Form1 class:private void ThreadTask()
{
int stp;
int newval;
Random rnd=new Random();
while(true)
{
stp=this.progressBar1.Step*rnd.Next(-1,2);
newval = this.progressBar1.Value + stp;
if (newval > this.progressBar1.Maximum)
newval = this.progressBar1.Maximum;
else if (newval < this.progressBar1.Minimum)
newval = this.progressBar1.Minimum;
this.progressBar1.Value = newval;
Thread.Sleep(100);
}
} |
| 10. | Add the following Load event handler for Form1. This code creates a new
thread, makes the thread a background thread, and then starts the thread.private void Form1_Load(object sender, System.EventArgs e)
{
Thread trd = new Thread(new ThreadStart(this.ThreadTask));
trd.IsBackground = true;
trd.Start();
} |
Back to the top
Verify that it works
| 1. | Build and run the application. Notice that the value in
ProgressBar1 changes randomly. This is the new thread in
operation. |
| 2. | To demonstrate that the main thread is independent of the
thread that changes the value of ProgressBar1, click the
button on the form. You receive a dialog box with the following error message:This is the main thread |
Wait for input. Notice that the value in
ProgressBar1 continues to change.
Back to the top
Troubleshoot
In more complex applications, make sure that you synchronize
multiple threads when you access shared variables. For more information, see
the
lock statement and related topics in the Visual C# .NET
Online Help documentation.
Back to the top
For more information, visit the following Microsoft Web site
or the .NET Framework SDK Documentation:
Back to the top
Help and Support
