EventAttribute.Message Property

Definition

Namespace:

System.Diagnostics.Tracing

Assemblies:

netstandard.dll, System.Diagnostics.Tracing.dll

Source:

EventSource.cs

Gets or sets the message for the event.

public:
 property System::String ^ Message { System::String ^ get(); void set(System::String ^ value); };

public string? Message { get; set; }

member this.Message : string with get, set

Public Property Message As String

Property Value

String

The message for the event.

Examples

The following example shows how to use the Message property to specify event messages. This code example is part of a larger example provided for the EventSource class.

[Event(1, Message = "Application Failure: {0}", Level = EventLevel.Error, Keywords = Keywords.Diagnostic)]
public void Failure(string message) { WriteEvent(1, message); }

<[Event](1, Message:="Application Failure: {0}", Level:=EventLevel.Error, Keywords:=Keywords.Diagnostic)> _
Public Sub Failure(ByVal message As String)
    WriteEvent(1, message)
End Sub

[Event(2, Message = "Starting up.", Keywords = Keywords.Perf, Level = EventLevel.Informational)]
public void Startup() { WriteEvent(2); }

<[Event](2, Message:="Starting up.", Keywords:=Keywords.Perf, Level:=EventLevel.Informational)> _
Public Sub Startup()
    WriteEvent(2)
End Sub

[Event(3, Message = "loading page {1} activityID={0}", Opcode = EventOpcode.Start,
    Task = Tasks.Page, Keywords = Keywords.Page, Level = EventLevel.Informational)]
public void PageStart(int ID, string url) { if (IsEnabled()) WriteEvent(3, ID, url); }

<[Event](3, Message:="loading page {1} activityID={0}", Opcode:=EventOpcode.Start, Task:=Tasks.Page, Keywords:=Keywords.Page, Level:=EventLevel.Informational)> _
Public Sub PageStart(ByVal ID As Integer, ByVal url As String)
    If IsEnabled() Then
        WriteEvent(3, ID, url)
    End If
End Sub

Remarks

You can use standard .NET Framework substitution operators (for example, {1}) in the string). They will be replaced with the string representation of the corresponding part of the event payload.

[Event(1, Message = "Application Failure: {0}", Level = EventLevel.Error, Keywords = Keywords.Diagnostic)]  
        public void Failure(string message) { WriteEvent(1, message); }