Debug Class
 

Provides a set of methods and properties that help debug your code.

Namespace:   System.Diagnostics
Assembly:  System (in System.dll)

Inheritance Hierarchy
SystemObject
  System.DiagnosticsDebug

Syntax
public static class Debug
public ref class Debug abstract sealed 
[<AbstractClass>]
[<Sealed>]
type Debug = class end
Public NotInheritable Class Debug
Properties
NameDescription
System_CAPS_pubproperty System_CAPS_static

Gets or sets a value indicating whether Flush should be called on the after every write.

System_CAPS_pubproperty System_CAPS_static

Gets or sets the indent level.

System_CAPS_pubproperty System_CAPS_static

Gets or sets the number of spaces in an indent.

System_CAPS_pubproperty System_CAPS_static

Gets the collection of listeners that is monitoring the debug output.

Methods
NameDescription
System_CAPS_pubmethod System_CAPS_static Assert

Checks for a condition; if the condition is false, displays a message box that shows the call stack.

System_CAPS_pubmethod System_CAPS_static Assert

Checks for a condition; if the condition is false, outputs a specified message and displays a message box that shows the call stack.

System_CAPS_pubmethod System_CAPS_static Assert

Checks for a condition; if the condition is false, outputs two specified messages and displays a message box that shows the call stack.

System_CAPS_pubmethod System_CAPS_static Assert

Checks for a condition; if the condition is false, outputs two messages (simple and formatted) and displays a message box that shows the call stack.

System_CAPS_pubmethod System_CAPS_static Close

Flushes the output buffer and then calls the Close method on each of the .

System_CAPS_pubmethod System_CAPS_static Fail

Emits the specified error message.

System_CAPS_pubmethod System_CAPS_static Fail

Emits an error message and a detailed error message.

System_CAPS_pubmethod System_CAPS_static Flush

Flushes the output buffer and causes buffered data to write to the collection.

System_CAPS_pubmethod System_CAPS_static Indent

Increases the current by one.

System_CAPS_pubmethod System_CAPS_static Print

Writes a message followed by a line terminator to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static Print

Writes a formatted string followed by a line terminator to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static Unindent

Decreases the current by one.

System_CAPS_pubmethod System_CAPS_static Write

Writes the value of the object's ToString method to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static Write

Writes a category name and the value of the object's ToString method to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static Write

Writes a message to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static Write

Writes a category name and message to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static WriteIf

Writes the value of the object's ToString method to the trace listeners in the collection if a condition is true.

System_CAPS_pubmethod System_CAPS_static WriteIf

Writes a category name and the value of the object's ToString method to the trace listeners in the collection if a condition is true.

System_CAPS_pubmethod System_CAPS_static WriteIf

Writes a message to the trace listeners in the collection if a condition is true.

System_CAPS_pubmethod System_CAPS_static WriteIf

Writes a category name and message to the trace listeners in the collection if a condition is true.

System_CAPS_pubmethod System_CAPS_static WriteLine

Writes the value of the object's ToString method to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static WriteLine

Writes a category name and the value of the object's ToString method to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static WriteLine

Writes a message followed by a line terminator to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static WriteLine

Writes a formatted message followed by a line terminator to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static WriteLine

Writes a category name and message to the trace listeners in the collection.

System_CAPS_pubmethod System_CAPS_static WriteLineIf

Writes the value of the object's ToString method to the trace listeners in the collection if a condition is true.

System_CAPS_pubmethod System_CAPS_static WriteLineIf

Writes a category name and the value of the object's ToString method to the trace listeners in the collection if a condition is true.

System_CAPS_pubmethod System_CAPS_static WriteLineIf

Writes a message to the trace listeners in the collection if a condition is true.

System_CAPS_pubmethod System_CAPS_static WriteLineIf

Writes a category name and message to the trace listeners in the collection if a condition is true.

Remarks

If you use methods in the Debug class to print debugging information and check your logic with assertions, you can make your code more robust without impacting the performance and code size of your shipping product.

This class provides methods to display an Assert dialog box, and to emit an assertion that will always fail. This class provides write methods in the following variations: Write, WriteLine, WriteIf and WriteLineIf.

The BooleanSwitch and TraceSwitch classes provide means to dynamically control the tracing output. You can modify the values of these switches without recompiling your application. For information on using the configuration file to set a switch, see the Switch class and the Trace Switches topic.

You can customize the tracing output's target by adding TraceListener instances to or removing instances from the collection. The collection is shared by both the Debug and the Trace classes; adding a trace listener to either class adds the listener to both. By default, the DefaultTraceListener class emits trace output.

System_CAPS_noteNote

Adding a trace listener to the collection can cause an exception to be thrown while tracing, if a resource used by the trace listener is not available. The conditions and the exception thrown depend on the trace listener and cannot be enumerated in this topic. It may be useful to place calls to the Debug methods in try/catch blocks to detect and handle any exceptions from trace listeners.

You can modify the level of indentation using the Indent method or the property. To modify the indent spacing, use the property. You can specify whether to automatically flush the output buffer after each write by setting the property to true.

To set the and for Debug, you can edit the configuration file corresponding to the name of your application. The configuration file should be formatted as shown in the following example.

<configuration>
  <system.diagnostics>
    <trace autoflush="true" indentsize="7" />
  </system.diagnostics>
</configuration>

The ConditionalAttribute attribute is applied to the methods of Debug. Compilers that support ConditionalAttribute ignore calls to these methods unless "DEBUG" is defined as a conditional compilation symbol. Refer to a compiler's documentation to determine whether ConditionalAttribute is supported and the syntax for defining a conditional compilation symbol.

System_CAPS_noteNote

In Visual Studio C# and Visual Basic projects, by default, the "DEBUG" conditional compilation symbol is defined for debug builds, and the "TRACE" symbol is defined for both debug and release builds. For information about how to disable this behavior, see the Visual Studio documentation. For information about conditional debugging in Visual C++, see Debug Class (C++/CLI).

To define the "DEBUG" conditional compilation symbol in C#, add the /d:DEBUG option to the compiler command line when you compile your code using a command line, or add #define DEBUG to the top of your file. In Visual Basic, add the /d:DEBUG=True option to the compiler command line or add #Const DEBUG=True to the file.

Examples

The following example uses Debug to indicate the beginning and end of a program's execution. The example also uses Indent and Unindent to distinguish the tracing output.

// Specify /d:DEBUG when compiling.

using System;
using System.Data;
using System.Diagnostics;

class Test
{
    static void Main()
    {
       Debug.Listeners.Add(new TextWriterTraceListener(Console.Out));
       Debug.AutoFlush = true;
       Debug.Indent();
       Debug.WriteLine("Entering Main");
       Console.WriteLine("Hello World.");
       Debug.WriteLine("Exiting Main"); 
       Debug.Unindent();
    }
}
' Specify /d:DEBUG=True when compiling.

Imports System
Imports System.Data
Imports System.Diagnostics

Class Test

    Shared Sub Main()

        Debug.Listeners.Add(New TextWriterTraceListener(Console.Out))
        Debug.AutoFlush = True
        Debug.Indent()
        Debug.WriteLine("Entering Main")
        Console.WriteLine("Hello World.")
        Debug.WriteLine("Exiting Main")
        Debug.Unindent()

    End Sub

End Class
// Specify /DDEBUG when compiling.

#using <System.dll>
using namespace System;
using namespace System::Diagnostics;

int main( void )
{
   #if defined(DEBUG)
   Debug::Listeners->Add( gcnew TextWriterTraceListener( Console::Out ) );
   Debug::AutoFlush = true;
   Debug::Indent();
   Debug::WriteLine( "Entering Main" );
   #endif
   Console::WriteLine( "Hello World." );
   #if defined(DEBUG)
   Debug::WriteLine( "Exiting Main" );
   Debug::Unindent();
   #endif
   return 0;
}
Version Information
Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Thread Safety

This type is thread safe.

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