TraceContextRecord.Category 属性

定义

命名空间:

System.Web

程序集:

System.Web.dll

获取跟踪记录的用户定义的类别。

public:
 property System::String ^ Category { System::String ^ get(); };

public string Category { get; }

member this.Category : string

Public ReadOnly Property Category As String

属性值

String

表示跟踪记录的类别的字符串。

示例

下面的代码示例演示如何访问 Category 的 TraceContextRecord属性，并将其及其关联的跟踪消息打印到流中 Response 。

<%@ 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>

注解

类别用于更好地将跟踪消息组织到可识别的组中，但可以是任何字符串。 类 TraceContext 使用 String.Empty 作为仅 message 采用参数的方法的默认类别。 ASP.NET 的默认类别（启用跟踪时写入多个跟踪记录）为“aspx.page”。

另请参阅

• ASP.NET 跟踪概述