TraceSwitch TraceSwitch TraceSwitch TraceSwitch Constructors

Definition

Overloads

TraceSwitch(String, String) TraceSwitch(String, String) TraceSwitch(String, String) TraceSwitch(String, String)

Initializes a new instance of the TraceSwitch class, using the specified display name and description.

TraceSwitch(String, String, String) TraceSwitch(String, String, String) TraceSwitch(String, String, String) TraceSwitch(String, String, String)

Initializes a new instance of the TraceSwitch class, using the specified display name, description, and default value for the switch.

TraceSwitch(String, String) TraceSwitch(String, String) TraceSwitch(String, String) TraceSwitch(String, String)

Initializes a new instance of the TraceSwitch class, using the specified display name and description.

public:
 TraceSwitch(System::String ^ displayName, System::String ^ description);
public TraceSwitch (string displayName, string description);
new System.Diagnostics.TraceSwitch : string * string -> System.Diagnostics.TraceSwitch
Public Sub New (displayName As String, description As String)

Parameters

displayName
String String String String

The name to display on a user interface.

description
String String String String

The description of the switch.

Examples

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.

   // Class-level declaration.
   /* Create a TraceSwitch to use in the entire application.*/
private:
   static TraceSwitch^ mySwitch = gcnew TraceSwitch( "General", "Entire Application" );

public:
   static void MyMethod()
   {
      // Write the message if the TraceSwitch level is set to Error or higher.
      if ( mySwitch->TraceError )
         Console::WriteLine( "My error message." );
      
      // Write the message if the TraceSwitch level is set to Verbose.
      if ( mySwitch->TraceVerbose )
         Console::WriteLine( "My second error message." );
   }

   static void main()
   {
      // Run the method that prints error messages based on the switch level.
      MyMethod();
   }
//Class-level declaration.
 /* Create a TraceSwitch to use in the entire application.*/
 static TraceSwitch mySwitch = new TraceSwitch("General", "Entire Application");
 
 static public void MyMethod() {
    // Write the message if the TraceSwitch level is set to Error or higher.
    if(mySwitch.TraceError)
       Console.WriteLine("My error message.");
 
    // Write the message if the TraceSwitch level is set to Verbose.
    if(mySwitch.TraceVerbose)
       Console.WriteLine("My second error message.");
 }
 
 public static void Main(string[] args) {
    // Run the method that prints error messages based on the switch level.
    MyMethod();
 }
 
' Class-level declaration.
' Create a TraceSwitch to use in the entire application. 
Private Shared mySwitch As New TraceSwitch("General", "Entire Application")    

Public Shared Sub MyMethod()
    ' Write the message if the TraceSwitch level is set to Error or higher.
    If mySwitch.TraceError Then
        Console.WriteLine("My error message.")
    End If 
    ' Write the message if the TraceSwitch level is set to Verbose.
    If mySwitch.TraceVerbose Then
        Console.WriteLine("My second error message.")
    End If
End Sub

Public Shared Sub Main()
    ' Run the method that prints error messages based on the switch level.
    MyMethod()
End Sub

Remarks

To set the level of your TraceSwitch, edit the configuration file that corresponds to the name of your application. In this file, you can add a switch and set its value, remove a switch, 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>  

Note

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:

private:
    static TraceSwitch^ appSwitch = gcnew TraceSwitch("mySwitch",
        "Switch in config file");

public:
    static void Main(array<String^>^ args)
    {
        //...
        Console::WriteLine("Trace switch {0} configured as {1}",
        appSwitch->DisplayName, appSwitch->Level.ToString());
        if (appSwitch->TraceError)
        {
            //...
        }
    }
private static TraceSwitch appSwitch = new TraceSwitch("mySwitch",
    "Switch in config file");

public static void Main(string[] args)
{
    //...
    Console.WriteLine("Trace switch {0} configured as {1}",
    appSwitch.DisplayName, appSwitch.Level.ToString());
    if (appSwitch.TraceError)
    {
        //...
    }
}
Private Shared appSwitch As new TraceSwitch("mySwitch", _
    "Switch in config file")

Public Shared Sub Main(args As String())
    '...
    Console.WriteLine("Trace switch {0} configured as {1}",
    appSwitch.DisplayName, appSwitch.Level.ToString())
    If appSwitch.TraceError = True  Then
        '...
    End If
End Sub

When the TraceSwitch constructor cannot find initial switch settings in the configuration file, the Level property of the new switch is set to TraceLevel.Off.

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.

Note

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

See also

TraceSwitch(String, String, String) TraceSwitch(String, String, String) TraceSwitch(String, String, String) TraceSwitch(String, String, String)

Initializes a new instance of the TraceSwitch class, using the specified display name, description, and default value for the switch.

public:
 TraceSwitch(System::String ^ displayName, System::String ^ description, System::String ^ defaultSwitchValue);
public TraceSwitch (string displayName, string description, string defaultSwitchValue);
new System.Diagnostics.TraceSwitch : string * string * string -> System.Diagnostics.TraceSwitch
Public Sub New (displayName As String, description As String, defaultSwitchValue As String)

Parameters

displayName
String String String String

The name to display on a user interface.

description
String String String String

The description of the switch.

defaultSwitchValue
String String String String

The default value of the switch.

Remarks

The displayName parameter is used to set the value of the DisplayName property, the description parameter is use to set the value of the Description property, and the defaultSwitchValue parameter is saved as a field and used to initialize the Value property on first reference. See the TraceSwitch(String, String) constructor for more information and a code example.

Applies to