Trace.Assert Method

Source:

Trace.cs

Source:

Trace.cs

Source:

Trace.cs

public:
 static void Assert(bool condition);

[System.Diagnostics.Conditional("TRACE")]
public static void Assert (bool condition);

[System.Diagnostics.Conditional("TRACE")]
[System.Runtime.CompilerServices.OverloadResolutionPriority(-1)]
public static void Assert (bool condition);

[<System.Diagnostics.Conditional("TRACE")>]
static member Assert : bool -> unit

[<System.Diagnostics.Conditional("TRACE")>]
[<System.Runtime.CompilerServices.OverloadResolutionPriority(-1)>]
static member Assert : bool -> unit

Public Shared Sub Assert (condition As Boolean)

Parameters

Attributes

ConditionalAttribute OverloadResolutionPriorityAttribute

Examples

The following example creates an index for an array. Then some action is performed that sets the value of the index. Next the code calls Assert to verify the index value is valid. If it is not valid, the Assert outputs the call stack.

protected:
   // Create an index for an array.
   int index;

   void Method()
   {
      // Perform some action that sets the index.
      // Test that the index value is valid.
      #if defined(TRACE)
      Trace::Assert( index > -1 );
      #endif
   }

// Create an index for an array.
int index;

void Method()
{
    // Perform some action that sets the index.

    // Test that the index value is valid.
    Trace.Assert(index > -1);
}

' Create an index for an array.
Protected index As Integer    

Protected Sub Method()
    ' Perform some action that sets the index.
    ' Test that the index value is valid. 
    Trace.Assert(index > -1)
End Sub

Remarks

Use the Trace.Assert method if you want to do assertions in release builds. The Debug.Assert method works only in debug builds. For more information, see Assertions in Managed Code.

Typically, the Assert(Boolean) method is used to identify logic errors during program development. Assert(Boolean) evaluates the condition. If the result is false, it sends a failure message to the Listeners collection. You can customize this behavior by adding a TraceListener to, or removing one from, the Listeners collection.

When the application runs in user-interface mode, it displays a message box that shows the call stack with file and line numbers. The message box contains three buttons: Abort, Retry, and Ignore. Clicking the Abort button terminates the application. Clicking Retry sends you to the code in the debugger if your application is running in a debugger, or offers to open a debugger if it is not. Clicking Ignore continues with the next instruction in the code.

For .NET Framework apps, you can change the behavior of the DefaultTraceListener in the configuration file that corresponds to the name of your application. In this file, you can enable and disable the assert message box or set the DefaultTraceListener.LogFileName property. The configuration file should be formatted as follows:

<configuration>  
  <system.diagnostics>  
    <switches>  
      <add name="mySwitch" value="4"/>  
    </switches>  
    <trace autoflush="false" indentsize="4"/>  
    <assert assertuienabled="true" logfilename=".\TraceLog.txt"/>  
  </system.diagnostics>  
</configuration>  

See also

• Debug
• Trace
• BooleanSwitch
• TraceSwitch
• TraceListener
• DefaultTraceListener
• ConditionalAttribute

Source:

Trace.cs

Source:

Trace.cs

Source:

Trace.cs

public:
 static void Assert(bool condition, System::String ^ message);

[System.Diagnostics.Conditional("TRACE")]
public static void Assert (bool condition, string? message);

[System.Diagnostics.Conditional("TRACE")]
public static void Assert (bool condition, string? message = default);

[System.Diagnostics.Conditional("TRACE")]
public static void Assert (bool condition, string message);

[<System.Diagnostics.Conditional("TRACE")>]
static member Assert : bool * string -> unit

Public Shared Sub Assert (condition As Boolean, message As String)

Public Shared Sub Assert (condition As Boolean, Optional message As String = Nothing)

Parameters

Attributes

ConditionalAttribute

Examples

The following example checks to see that the type parameter is valid. If the type passed in is null, the Assert outputs a message.

public:
   static void MyMethod( Type^ type, Type^ baseType )
   {
     #if defined(TRACE)
     Trace::Assert( type != nullptr, "Type parameter is null" );
     #endif
      
      // Perform some processing.
   }

public static void MyMethod(Type type, Type baseType)
{
    Trace.Assert(type != null, "Type parameter is null");

    // Perform some processing.
}

Public Shared Sub MyMethod(type As Type, baseType As Type)
    Trace.Assert( Not (type Is Nothing), "Type parameter is null")

    ' Perform some processing.
End Sub

Remarks

Use the Trace.Assert method if you want to do assertions in release builds. The Debug.Assert method works only in debug builds. For more information, see Assertions in Managed Code.

Typically, the Assert(Boolean, String) method is used to identify logic errors during program development. Assert(Boolean, String) evaluates the condition. If the result is false, it sends the specified diagnostic message to the Listeners collection. You can customize this behavior by adding a TraceListener to, or removing one from, the Listeners collection.

When the application runs in user-interface mode, it displays a message box that shows the call stack with file and line numbers. The message box contains three buttons: Abort, Retry, and Ignore. Clicking the Abort button terminates the application. Clicking Retry sends you to the code in the debugger if your application is running in a debugger, or offers to open a debugger if it is not. Clicking Ignore continues with the next instruction in the code.

For .NET Framework apps, you can change the behavior of the DefaultTraceListener in the configuration file that corresponds to the name of your application. In this file, you can enable and disable the assert message box or set the DefaultTraceListener.LogFileName property. The configuration file should be formatted as follows:

<configuration>  
  <system.diagnostics>  
    <switches>  
      <add name="mySwitch" value="4"/>  
    </switches>  
    <trace autoflush="false" indentsize="4"/>  
    <assert assertuienabled="true" logfilename=".\TraceLog.txt"/>  
  </system.diagnostics>  
</configuration>  

See also

• Debug
• Trace
• BooleanSwitch
• TraceSwitch
• TraceListener
• DefaultTraceListener
• ConditionalAttribute

Source:

Trace.cs

Source:

Trace.cs

Source:

Trace.cs

public:
 static void Assert(bool condition, System::String ^ message, System::String ^ detailMessage);

[System.Diagnostics.Conditional("TRACE")]
public static void Assert (bool condition, string? message, string? detailMessage);

[System.Diagnostics.Conditional("TRACE")]
public static void Assert (bool condition, string message, string detailMessage);

[<System.Diagnostics.Conditional("TRACE")>]
static member Assert : bool * string * string -> unit

Public Shared Sub Assert (condition As Boolean, message As String, detailMessage As String)

Parameters

Attributes

ConditionalAttribute

Examples

The following example checks to see that the type parameter is valid. If the type passed in is null, the Assert outputs a message.

public:
   static void MyMethod( Type^ type, Type^ baseType )
   {
      #if defined(TRACE)
      Trace::Assert( type != nullptr, "Type parameter is null", "Can't get object for null type" );
      #endif
      
      // Perform some processing.
   }

public static void MyMethod(Type type, Type baseType)
{
    Trace.Assert(type != null, "Type parameter is null",
       "Can't get object for null type");

    // Perform some processing.
}

Public Shared Sub MyMethod(type As Type, baseType As Type)
    Trace.Assert( Not (type Is Nothing), "Type parameter is null", _
        "Can't get object for null type")

    ' Perform some processing.
End Sub

Remarks

Use the Trace.Assert method if you want to do assertions in release builds. The Debug.Assert method works only in debug builds. For more information, see Assertions in Managed Code.

Typically, the Assert(Boolean, String, String) method is used to identify logic errors during program development. Assert evaluates the condition. If the result is false, it sends the specified diagnostic message and detailed message to the Listeners collection. You can customize this behavior by adding a TraceListener to, or removing one from, the Listeners collection.

When the application runs in user-interface mode, it displays a message box that shows the call stack with file and line numbers. The message box contains three buttons: Abort, Retry, and Ignore. Clicking the Abort button terminates the application. Clicking Retry sends you to the code in the debugger if your application is running in a debugger, or offers to open a debugger if it is not. Clicking Ignore continues with the next instruction in the code.

For .NET Framework apps, you can change the behavior of the DefaultTraceListener in the configuration file that corresponds to the name of your application. In this file, you can enable and disable the assert message box or set the DefaultTraceListener.LogFileName property. The configuration file should be formatted as follows:

<configuration>  
  <system.diagnostics>  
    <switches>  
      <add name="mySwitch" value="4"/>  
    </switches>  
    <trace autoflush="false" indentsize="4"/>  
    <assert assertuienabled="true" logfilename=".\TraceLog.txt"/>  
  </system.diagnostics>  
</configuration>  

See also

• Debug
• Trace
• BooleanSwitch
• TraceSwitch
• TraceListener
• DefaultTraceListener
• ConditionalAttribute