Microsoft KB Archive/305705

= How to programmatically start the default Internet Browser by using Visual Basic .NET or Visual Basic 2005 =

Article ID: 305705

Article Last Modified on 12/6/2006

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APPLIES TO


 * Microsoft Visual Basic 2005
 * Microsoft Visual Basic .NET 2003 Standard Edition
 * Microsoft Visual Basic .NET 2002 Standard Edition

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This article was previously published under Q305705





For a Microsoft Visual C# .NET version of this article, see 305703.

For a Microsoft Visual C++ .NET version of this article, see 307382.

IN THIS TASK
SUMMARY
 * Requirements
 * Specify the URL, FTP, or File to Open
 * Use the Process Class Start Method to Start the Browser
 * Provide Exception Handling
 * Complete Code Sample
 * Troubleshooting

REFERENCES



SUMMARY
This article demonstrates how to start the default Internet browser.

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Requirements

 * Microsoft Visual Studio .NET or Microsoft Visual Studio 2005

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Specify the URL, FTP, or File to Open
You can specify a URL, a file, or an FTP address. All three of these assignments are valid: Dim target As String = &quot;http://www.microsoft.com&quot; Dim target As String = &quot;ftp://ftp.microsoft.com&quot; Dim target As String = &quot;C:\Program Files\Microsoft Visual Studio\INSTALL.HTM&quot; back to the top

Use the Process Class Start Method to Start the Browser
The Process class contains a shared Start method. Because this is a shared method, you can call Start without having an instance of a Process class. System.Diagnostics.Process.Start(target) back to the top

Provide Exception Handling
Because you take advantage of the default UseShellExecute property when you call the Start method, you do not have to explicitly query the registry to determine which browser is the default. However, if you use this approach on a computer that does not have a browser installed, an exception occurs. This exception must be caught so that the appropriate action can be taken. This example explicitly traps for an error that is generated when the necessary registry key is not found and indicates that no browser is installed. In addition, a general exception handler is provided for other errors that may occur. The try...catch block is demonstrated in the complete code listing.

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Complete Code Sample
Dim target As String = &quot;http://www.microsoft.com&quot; 'Do not use more than one assignment at a time. 'This also works with FTP. 'Dim target As String = &quot;ftp://ftp.microsoft.com&quot; 'This also works with a file. 'Dim target As String = &quot;C:\Program Files\Microsoft Visual Studio\INSTALL.HTM&quot; Try System.Diagnostics.Process.Start(target)

Catch noBrowser As System.ComponentModel.Win32Exception _ When noBrowser.ErrorCode = -2147467259 MessageBox.Show(noBrowser.Message)

Catch other As System.ComponentModel.Win32Exception MessageBox.Show(other.Message)

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Troubleshooting
This code is highly dependent on the application-file type associations in the HKEY_CLASSES_ROOT hive of the registry. This can lead to unexpected results and exceptions if the registry is damaged. In addition, file types and extensions may also be associated with applications other than the browser. For example, HTM or HTML files may be associated with Web development software instead of the browser.

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