TraceContext.Write Method
Definition
Important
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Writes trace information to the trace log.
Overloads
| Write(String) |
Writes a trace message to the trace log. |
| Write(String, String) |
Writes trace information to the trace log, including a message and any user-defined categories. |
| Write(String, String, Exception) |
Writes trace information to the trace log, including any user-defined categories, trace messages, and error information. |
Write(String)
Writes a trace message to the trace log.
public:
void Write(System::String ^ message);public void Write (string message);member this.Write : string -> unitPublic Sub Write (message As String)Parameters
- message
- String
The trace message to write to the log.
Remarks
Every time the Write method is called, a TraceContext trace message is added to the TraceRecords messages collection, which is accessible when you handle the TraceFinished event. The message is added with its IsWarning property set to false and its ErrorInfo property set to null.
See also
Applies to
Write(String, String)
Writes trace information to the trace log, including a message and any user-defined categories.
public:
void Write(System::String ^ category, System::String ^ message);public void Write (string category, string message);member this.Write : string * string -> unitPublic Sub Write (category As String, message As String)Parameters
- category
- String
The trace category that receives the message.
- message
- String
The trace message to write to the log.
Examples
The following code example demonstrates how to call the Write method to write an error trace message to the trace log. In this example, the delegate iterates through the trace messages and writes them as an HTML table; however, you can write the same information to a database or a profiling tool consumer.
<%@ 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
Every time the Write method is called, a TraceContext trace message is added to the TraceRecords messages collection, which is accessible when you handle the TraceFinished event. The message is added with its IsWarning property set to false and its ErrorInfo property set to null.
See also
Applies to
Write(String, String, Exception)
Writes trace information to the trace log, including any user-defined categories, trace messages, and error information.
public:
void Write(System::String ^ category, System::String ^ message, Exception ^ errorInfo);public void Write (string category, string message, Exception errorInfo);member this.Write : string * string * Exception -> unitPublic Sub Write (category As String, message As String, errorInfo As Exception)Parameters
- category
- String
The trace category that receives the message.
- message
- String
The trace message to write to the log.
Examples
The following code example demonstrates how to call the Write method to write an error trace message to the trace log. In this example, different exceptions are traced as errors and warnings. When the page throws an ArgumentException, it writes a warning message using the Warn method. When the page throws an InvalidOperationException, it writes an error message using the Write method.
<%@ 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);
try {
throw new ArgumentException("Trace Test");
}
catch (InvalidOperationException ioe) {
// You can write an error trace message using the Write method.
Trace.Write("Exception Handling", "Exception: Page_Load.", ioe);
}
catch (ArgumentException ae) {
// You can write a warning trace message using the Warn method.
Trace.Warn("Exception Handling", "Warning: Page_Load.", ae);
}
}
// 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.
foreach(object o in e.TraceRecords)
{
r = (TraceContextRecord)o;
if (r.IsWarning) {
Response.Write(String.Format("warning message: {0} <BR>", r.Message));
}
else {
Response.Write(String.Format("error message: {0} <BR>", r.Message));
}
}
}
</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
Try
Dim ae As New ArgumentException("Trace Test")
Throw ae
catch ioe As InvalidOperationException
' You can write an error trace message using the Write method.
Trace.Write("Exception Handling", "Exception: Page_Load.", ioe)
Catch ae As ArgumentException
' You can write a warning trace message using the Warn method.
Trace.Warn("Exception Handling", "Warning: Page_Load.", ae)
End Try
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.
For Each o In e.TraceRecords
r = CType(o, TraceContextRecord)
If r.IsWarning Then
Response.Write(String.Format("warning message: {0} <BR>", r.Message))
Else
Response.Write(String.Format("error message: {0} <BR>", r.Message))
End If
Next
End Sub ' OnTraceFinished
</script>
Remarks
Every time the Write method is called, a TraceContext trace message is added to the TraceRecords messages collection, which is accessible when you handle the TraceFinished event. The message is added with its IsWarning property set to false, and the ErrorInfo property is set to the object passed by the errorInfo parameter.
