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TraceSwitch Class

Provides a multilevel switch to control tracing and debug output without recompiling your code.

System.Object
  System.Diagnostics.Switch
    System.Diagnostics.TraceSwitch

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

type TraceSwitch =  
    class 
        inherit Switch 
    end

The TraceSwitch type exposes the following members.

  NameDescription
Public methodTraceSwitch(String, String)Initializes a new instance of the TraceSwitch class, using the specified display name and description.
Public methodTraceSwitch(String, String, String)Initializes a new instance of the TraceSwitch class, using the specified display name, description, and default value for the switch.
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  NameDescription
Public propertyAttributesGets the custom switch attributes defined in the application configuration file. (Inherited from Switch.)
Public propertyDescriptionGets a description of the switch. (Inherited from Switch.)
Public propertyDisplayNameGets a name used to identify the switch. (Inherited from Switch.)
Public propertyLevelGets or sets the trace level that determines the messages the switch allows.
Protected propertySwitchSettingGets or sets the current setting for this switch. (Inherited from Switch.)
Public propertyTraceErrorGets a value indicating whether the switch allows error-handling messages.
Public propertyTraceInfoGets a value indicating whether the switch allows informational messages.
Public propertyTraceVerboseGets a value indicating whether the switch allows all messages.
Public propertyTraceWarningGets a value indicating whether the switch allows warning messages.
Protected propertyValueGets or sets the value of the switch. (Inherited from Switch.)
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  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Protected methodGetSupportedAttributesGets the custom attributes supported by the switch. (Inherited from Switch.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Protected methodOnSwitchSettingChangedUpdates and corrects the level for this switch. (Overrides Switch.OnSwitchSettingChanged().)
Protected methodOnValueChangedSets the SwitchSetting property to the integer equivalent of the Value property. (Overrides Switch.OnValueChanged().)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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You can use a trace switch to filter out messages based on their importance. The TraceSwitch class provides the TraceError, TraceWarning, TraceInfo, and TraceVerbose properties to test the level of the switch. The Level property gets or sets the switch's TraceLevel.

You can set the level of a TraceSwitch through the application configuration file and then use the configured TraceSwitch level in your application. Alternately, you can create a TraceSwitch in your code and set the level directly to instrument a specific section of code.

To configure a TraceSwitch, edit the configuration file for your application. In this file, you can add or remove a switch, set a switch's value, or clear all the switches previously set by the application. The configuration file should be formatted like the following example:

<configuration>
  <system.diagnostics>
    <switches>
      <add name="mySwitch" value="1" />
    </switches>
  </system.diagnostics>
</configuration>

This configuration section defines a TraceSwitch with the DisplayName set to mySwitch, and the Level set to 1, which corresponds to the enumeration value TraceLevel.Error.

NoteNote

In the .NET Framework version 2.0, you can use text to specify the value for a switch. For example, true for a BooleanSwitch or the text representing an enumeration value, such as Error for a TraceSwitch. The line <add name="mySwitch" value="Error" /> is equivalent to <add name="mySwitch" value="1" />.

In your application, you can use the configured switch level by creating a TraceSwitch with the same name, as shown in the following example:

No code example is currently available or this language may not be supported.

By default, the switch Level property is set using the value specified in the configuration file. If the TraceSwitch constructor cannot find initial switch settings in the configuration file, the Level of the new switch defaults to TraceLevel.Off.

You must enable tracing or debugging to use a switch. The following syntax is compiler specific. If you use compilers other than C# or Visual Basic, refer to the documentation for your compiler.

  • To enable debugging in C#, add the /d:DEBUG flag to the compiler command line when you compile your code, or add #define DEBUG to the top of your file. In Visual Basic, add the /d:DEBUG=True flag to the compiler command line.

  • To enable tracing in C#, add the /d:TRACE flag to the compiler command line when you compile your code, or add #define TRACE to the top of your file. In Visual Basic, add the /d:TRACE=True flag to the compiler command line.

NoteNote

These debug and trace compiler switches are not required when using the TraceSwitch class in isolation. They are only required in conjunction with Trace or Debug methods that are conditionally compiled.

For more information on instrumenting your application, see Debug and Trace. For more information about configuring and using trace switches, see Trace Switches.

NoteNote

To improve performance, you can make TraceSwitch members static in your class.

TopicLocation
How to: Configure Trace Switches.NET Framework: Debugging
How to: Create and Initialize Trace Switches.NET Framework: Debugging
How to: Configure Trace Switches.NET Framework: Debugging
How to: Create and Initialize Trace Switches.NET Framework: Debugging

The following code example creates a new TraceSwitch and uses the switch to determine whether to print error messages. The switch is created at the class level. MyMethod writes the first error message if the Level property is set to TraceLevel.Error or higher. However, MyMethod does not write the second error message if the Level is less than TraceLevel.Verbose.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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