| title | Send messages to the Output window | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| description | Write run-time messages to the Output window in Visual Studio using the Debug class or the Trace class, which are part of the System.Diagnostics class library. | ||||||||||||
| ms.date | 10/03/2024 | ||||||||||||
| ms.topic | how-to | ||||||||||||
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| author | mikejo5000 | ||||||||||||
| ms.author | mikejo | ||||||||||||
| ms.subservice | debug-diagnostics |
You can write run-time messages to the Output window using the xref:System.Diagnostics.Debug class or the xref:System.Diagnostics.Trace class, which are part of the xref:System.Diagnostics class library. Use the xref:System.Diagnostics.Debug class if you only want output in the Debug version of your program. Use the xref:System.Diagnostics.Trace class if you want output in both the Debug and Release versions.
The xref:System.Diagnostics.Trace and xref:System.Diagnostics.Debug classes provide the following output methods:
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Various Write methods, which output information without breaking execution. These methods replace the
Debug.Printmethod used in older versions of Visual Basic. -
xref:System.Diagnostics.Debug.Assert%2A?displayProperty=fullName and xref:System.Diagnostics.Trace.Assert%2A?displayProperty=fullName methods, which break execution and output information if a specified condition fails. By default, the
Assertmethod displays the information in a dialog box. For more information, see Assertions in managed code. -
The xref:System.Diagnostics.Debug.Fail%2A?displayProperty=fullName and xref:System.Diagnostics.Trace.Fail%2A?displayProperty=fullName methods, which always break execution and output information. By default, the
Failmethods display the information in a dialog box.
The Output window can also display information about:
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Modules the debugger has loaded or unloaded.
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Exceptions that are thrown.
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Processes that exit.
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Threads that exit.