Edit

Kongsi melalui

TraceContextRecord.Category Property

  • Reference

Definition

Namespace:
System.Web
Assembly:
System.Web.dll

Gets the user-defined category for the trace record.

public:
 property System::String ^ Category { System::String ^ get(); };
public string Category { get; }
member this.Category : string
Public ReadOnly Property Category As String

Property Value

String

A string that represents a category for the trace record.

Examples

The following code example demonstrates how to access the Category property of a TraceContextRecord, and print it and its associated trace message to the Response stream.

<%@ Page language="c#" Trace="true" %>
<script runat="server">
void Page_Load(object sender, EventArgs e)
{
    // Register a handler for the TraceFinished event.
    Trace.TraceFinished += new 
        TraceContextEventHandler(this.OnTraceFinished);

    // Write a trace message.
    Trace.Write("Web Forms Infrastructure Methods", "USERMESSAGE: Page_Load complete.");
}
 
// A TraceContextEventHandler for the TraceFinished event.
void OnTraceFinished(object sender, TraceContextEventArgs e)
{
    TraceContextRecord r = null;    
    
    // Iterate through the collection of trace records and write 
    // them to the response stream.
    Response.Write("<table>");
    foreach(object o in e.TraceRecords)
    {
        r = (TraceContextRecord)o;
        Response.Write(String.Format("<tr><td>{0}</td><td>{1}</td></tr>", r.Message, r.Category));        
    }
    Response.Write("</table>");
}       
</script>

<%@ Page language="VB" Trace="true" %>
<script runat="server">
' The Page_Load method.
Private Sub Page_Load(sender As Object, e As EventArgs)

    ' Register a handler for the TraceFinished event.
    AddHandler Trace.TraceFinished, AddressOf OnTraceFinished

    ' Write a trace message.
    Trace.Write("Web Forms Infrastructure Methods", "USERMESSAGE: Page_Load complete.")
End Sub ' Page_Load
 
' A TraceContextEventHandler for the TraceFinished event.
Private Sub OnTraceFinished(sender As Object, e As TraceContextEventArgs)

    Dim r As TraceContextRecord
    Dim o As Object
    
    ' Iterate through the collection of trace records and write 
    ' them to the response stream.
    Response.Write("<table>")
    For Each o In e.TraceRecords
        r = CType(o, TraceContextRecord)
        Response.Write(String.Format("<tr><td>{0}</td><td>{1}</td></tr>", r.Message, r.Category))
    Next
    Response.Write("</table>")

End Sub ' OnTraceFinished
</script>

Remarks

The category is used to better organize trace messages into recognizable groups, but can be any string. The TraceContext class uses String.Empty as its default category for methods that take only a message parameter. The default category for ASP.NET, which writes several trace records when tracing is enabled, is "aspx.page".

Applies to

See also