TraceSource Class
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Provides a set of methods and properties that enable applications to trace the execution of code and associate trace messages with their source.
public ref class TraceSourcepublic class TraceSourcetype TraceSource = classPublic Class TraceSource- Inheritance
-
TraceSource
Examples
The following code example shows the use of the TraceSource class to forward traces to listeners. The example also demonstrates switch and filter usage.
/////////////////////////////////////////////////////////////////////////////////
//
// NAME TraceSource2.cpp : main project file
//
/////////////////////////////////////////////////////////////////////////////////
// The following configuration file can be used with this sample.
// When using a configuration file #define ConfigFile.
// <source name="TraceTest" switchName="SourceSwitch" switchType="System.Diagnostics.SourceSwitch" >
// <add name="console" type="System.Diagnostics.ConsoleTraceListener" initializeData="false" />
// <remove name ="Default" />
// <!-- You can set the level at which tracing is to occur -->
// <add name="SourceSwitch" value="Warning" />
// <!-- You can turn tracing off -->
// <!--add name="SourceSwitch" value="Off" -->
// <trace autoflush="true" indentsize="4"></trace>
#define TRACE
//#define ConfigFile
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Diagnostics;
using namespace System::Reflection;
using namespace System::IO;
using namespace System::Security::Permissions;
void DisplayProperties(TraceSource^ ts); // Forward Declaration
int main()
{
TraceSource^ ts = gcnew TraceSource("TraceTest");
try
{
// Initialize trace switches.
#if(!ConfigFile)
SourceSwitch^ sourceSwitch = gcnew SourceSwitch("SourceSwitch", "Verbose");
ts->Switch = sourceSwitch;
int idxConsole = ts->Listeners->Add(gcnew System::Diagnostics::ConsoleTraceListener());
ts->Listeners[idxConsole]->Name = "console";
#endif
DisplayProperties(ts);
ts->Listeners["console"]->TraceOutputOptions |= TraceOptions::Callstack;
ts->TraceEvent(TraceEventType::Warning, 1);
ts->Listeners["console"]->TraceOutputOptions = TraceOptions::DateTime;
// Issue file not found message as a warning.
ts->TraceEvent(TraceEventType::Warning, 2, "File Test not found");
// Issue file not found message as a verbose event using a formatted string.
ts->TraceEvent(TraceEventType::Verbose, 3, "File {0} not found.", "test");
// Issue file not found message as information.
ts->TraceInformation("File {0} not found.", "test");
ts->Listeners["console"]->TraceOutputOptions |= TraceOptions::LogicalOperationStack;
// Issue file not found message as an error event.
ts->TraceEvent(TraceEventType::Error, 4, "File {0} not found.", "test");
// Test the filter on the ConsoleTraceListener.
ts->Listeners["console"]->Filter = gcnew SourceFilter("No match");
ts->TraceData(TraceEventType::Error, 5,
"SourceFilter should reject this message for the console trace listener.");
ts->Listeners["console"]->Filter = gcnew SourceFilter("TraceTest");
ts->TraceData(TraceEventType::Error, 6,
"SourceFilter should let this message through on the console trace listener.");
ts->Listeners["console"]->Filter = nullptr;
// Use the TraceData method.
ts->TraceData(TraceEventType::Warning, 7, gcnew array<Object^>{ "Message 1", "Message 2" });
// Activity tests.
ts->TraceEvent(TraceEventType::Start, 9, "Will not appear until the switch is changed.");
ts->Switch->Level = SourceLevels::ActivityTracing | SourceLevels::Critical;
ts->TraceEvent(TraceEventType::Suspend, 10, "Switch includes ActivityTracing, this should appear");
ts->TraceEvent(TraceEventType::Critical, 11, "Switch includes Critical, this should appear");
ts->Flush();
ts->Close();
Console::WriteLine("Press enter key to exit.");
Console::Read();
}
catch (Exception ^e)
{
// Catch any unexpected exception.
Console::WriteLine("Unexpected exception: " + e->ToString());
Console::Read();
}
}
void DisplayProperties(TraceSource^ ts)
{
Console::WriteLine("TraceSource name = " + ts->Name);
// Console::WriteLine("TraceSource switch level = " + ts->Switch->Level); // error C3063: operator '+': all operands must have the same enumeration type
Console::WriteLine("TraceSource switch level = {0}", ts->Switch->Level); // SUCCESS: does compile. Weird
Console::WriteLine("TraceSource Attributes Count " + ts->Attributes->Count); // SUCCESS: also compiles. Really weird
Console::WriteLine("TraceSource Attributes Count = {0}", ts->Attributes->Count); // SUCCESS: okay, I give up. Somebody call me a cab.
Console::WriteLine("TraceSource switch = " + ts->Switch->DisplayName);
array<SwitchAttribute^>^ switches = SwitchAttribute::GetAll(TraceSource::typeid->Assembly);
for (int i = 0; i < switches->Length; i++)
{
Console::WriteLine("Switch name = " + switches[i]->SwitchName);
Console::WriteLine("Switch type = " + switches[i]->SwitchType);
}
#if(ConfigFile)
// Get the custom attributes for the TraceSource.
Console::WriteLine("Number of custom trace source attributes = "
+ ts.Attributes.Count);
foreach (DictionaryEntry de in ts.Attributes)
Console::WriteLine("Custom trace source attribute = "
+ de.Key + " " + de.Value);
// Get the custom attributes for the trace source switch.
foreach (DictionaryEntry de in ts.Switch.Attributes)
Console::WriteLine("Custom switch attribute = "
+ de.Key + " " + de.Value);
#endif
Console::WriteLine("Number of listeners = " + ts->Listeners->Count);
for each (TraceListener ^ traceListener in ts->Listeners)
{
Console::Write("TraceListener: " + traceListener->Name + "\t");
// The following output can be used to update the configuration file.
Console::WriteLine("AssemblyQualifiedName = " +
(traceListener->GetType()->AssemblyQualifiedName));
}
}
// The following configuration file can be used with this sample.
// When using a configuration file #define ConfigFile.
// <source name="TraceTest" switchName="SourceSwitch" switchType="System.Diagnostics.SourceSwitch" >
// <add name="console" type="System.Diagnostics.ConsoleTraceListener" initializeData="false" />
// <remove name ="Default" />
// <!-- You can set the level at which tracing is to occur -->
// <add name="SourceSwitch" value="Warning" />
// <!-- You can turn tracing off -->
// <!--add name="SourceSwitch" value="Off" -->
// <trace autoflush="true" indentsize="4"></trace>
#define TRACE
//#define ConfigFile
using System;
using System.Collections;
using System.Diagnostics;
using System.Reflection;
using System.IO;
using System.Security.Permissions;
namespace Testing
{
class TraceTest
{
// Initialize the trace source.
static TraceSource ts = new TraceSource("TraceTest");
[SwitchAttribute("SourceSwitch", typeof(SourceSwitch))]
static void Main()
{
try
{
// Initialize trace switches.
#if(!ConfigFile)
SourceSwitch sourceSwitch = new SourceSwitch("SourceSwitch", "Verbose");
ts.Switch = sourceSwitch;
int idxConsole = ts.Listeners.Add(new System.Diagnostics.ConsoleTraceListener());
ts.Listeners[idxConsole].Name = "console";
#endif
DisplayProperties(ts);
ts.Listeners["console"].TraceOutputOptions |= TraceOptions.Callstack;
ts.TraceEvent(TraceEventType.Warning, 1);
ts.Listeners["console"].TraceOutputOptions = TraceOptions.DateTime;
// Issue file not found message as a warning.
ts.TraceEvent(TraceEventType.Warning, 2, "File Test not found");
// Issue file not found message as a verbose event using a formatted string.
ts.TraceEvent(TraceEventType.Verbose, 3, "File {0} not found.", "test");
// Issue file not found message as information.
ts.TraceInformation("File {0} not found.", "test");
ts.Listeners["console"].TraceOutputOptions |= TraceOptions.LogicalOperationStack;
// Issue file not found message as an error event.
ts.TraceEvent(TraceEventType.Error, 4, "File {0} not found.", "test");
// Test the filter on the ConsoleTraceListener.
ts.Listeners["console"].Filter = new SourceFilter("No match");
ts.TraceData(TraceEventType.Error, 5,
"SourceFilter should reject this message for the console trace listener.");
ts.Listeners["console"].Filter = new SourceFilter("TraceTest");
ts.TraceData(TraceEventType.Error, 6,
"SourceFilter should let this message through on the console trace listener.");
ts.Listeners["console"].Filter = null;
// Use the TraceData method.
ts.TraceData(TraceEventType.Warning, 7, new object());
ts.TraceData(TraceEventType.Warning, 8, new object[] { "Message 1", "Message 2" });
// Activity tests.
ts.TraceEvent(TraceEventType.Start, 9, "Will not appear until the switch is changed.");
ts.Switch.Level = SourceLevels.ActivityTracing | SourceLevels.Critical;
ts.TraceEvent(TraceEventType.Suspend, 10, "Switch includes ActivityTracing, this should appear");
ts.TraceEvent(TraceEventType.Critical, 11, "Switch includes Critical, this should appear");
ts.Flush();
ts.Close();
Console.WriteLine("Press any key to exit.");
Console.Read();
}
catch (Exception e)
{
// Catch any unexpected exception.
Console.WriteLine("Unexpected exception: " + e.ToString());
Console.Read();
}
}
public static void DisplayProperties(TraceSource ts)
{
Console.WriteLine("TraceSource name = " + ts.Name);
Console.WriteLine("TraceSource switch level = " + ts.Switch.Level);
Console.WriteLine("TraceSource switch = " + ts.Switch.DisplayName);
SwitchAttribute[] switches = SwitchAttribute.GetAll(typeof(TraceTest).Assembly);
for (int i = 0; i < switches.Length; i++)
{
Console.WriteLine("Switch name = " + switches[i].SwitchName);
Console.WriteLine("Switch type = " + switches[i].SwitchType);
}
#if(ConfigFile)
// Get the custom attributes for the TraceSource.
Console.WriteLine("Number of custom trace source attributes = "
+ ts.Attributes.Count);
foreach (DictionaryEntry de in ts.Attributes)
Console.WriteLine("Custom trace source attribute = "
+ de.Key + " " + de.Value);
// Get the custom attributes for the trace source switch.
foreach (DictionaryEntry de in ts.Switch.Attributes)
Console.WriteLine("Custom switch attribute = "
+ de.Key + " " + de.Value);
#endif
Console.WriteLine("Number of listeners = " + ts.Listeners.Count);
foreach (TraceListener traceListener in ts.Listeners)
{
Console.Write("TraceListener: " + traceListener.Name + "\t");
// The following output can be used to update the configuration file.
Console.WriteLine("AssemblyQualifiedName = " +
(traceListener.GetType().AssemblyQualifiedName));
}
}
}
}
' The following configuration file can be used with this sample.
' When using a configuration file #define ConfigFile.
' <source name="TraceTest" switchName="SourceSwitch" switchType="System.Diagnostics.SourceSwitch" >
' <add name="console" type="System.Diagnostics.ConsoleTraceListener" initializeData="false" />
' <remove name ="Default" />
' <!-- You can set the level at which tracing is to occur -->
' <add name="SourceSwitch" value="Warning" />
' <!-- You can turn tracing off -->
' <!--add name="SourceSwitch" value="Off" -->
' <trace autoflush="true" indentsize="4"></trace>
#Const TRACE = True
'#Const ConfigFile = True
Imports System.Collections
Imports System.Diagnostics
Imports System.Reflection
Imports System.IO
Imports System.Security.Permissions
Class TraceTest
' Initialize the trace source.
Private Shared ts As New TraceSource("TraceTest")
<SwitchAttribute("SourceSwitch", GetType(SourceSwitch))> _
Shared Sub Main()
Try
' Initialize trace switches.
#If (ConfigFile = False) Then
Dim sourceSwitch As New SourceSwitch("SourceSwitch", "Verbose")
ts.Switch = sourceSwitch
Dim idxConsole As New Integer()
idxConsole = ts.Listeners.Add(New System.Diagnostics.ConsoleTraceListener())
ts.Listeners(idxConsole).Name = "console"
#End If
DisplayProperties(ts)
ts.Listeners("console").TraceOutputOptions = ts.Listeners("console").TraceOutputOptions Or TraceOptions.Callstack
ts.TraceEvent(TraceEventType.Warning, 1)
ts.Listeners("console").TraceOutputOptions = TraceOptions.DateTime
' Issue file not found message as a warning.
ts.TraceEvent(TraceEventType.Warning, 2, "File Test not found")
' Issue file not found message as a verbose event using a formatted string.
ts.TraceEvent(TraceEventType.Verbose, 3, "File {0} not found.", "test")
' Issue file not found message as information.
ts.TraceInformation("File {0} not found.", "test")
ts.Listeners("console").TraceOutputOptions = ts.Listeners("console").TraceOutputOptions Or TraceOptions.LogicalOperationStack
' Issue file not found message as an error event.
ts.TraceEvent(TraceEventType.Error, 4, "File {0} not found.", "test")
' Test the filter on the ConsoleTraceListener.
ts.Listeners("console").Filter = New SourceFilter("No match")
ts.TraceData(TraceEventType.Error, 5, "SourceFilter should reject this message for the console trace listener.")
ts.Listeners("console").Filter = New SourceFilter("TraceTest")
ts.TraceData(TraceEventType.Error, 6, "SourceFilter should let this message through on the console trace listener.")
ts.Listeners("console").Filter = Nothing
' Use the TraceData method.
ts.TraceData(TraceEventType.Warning, 7, New Object())
ts.TraceData(TraceEventType.Warning, 8, New Object() {"Message 1", "Message 2"})
' Activity tests.
ts.TraceEvent(TraceEventType.Start, 9, "Will not appear until the switch is changed.")
ts.Switch.Level = SourceLevels.ActivityTracing Or SourceLevels.Critical
ts.TraceEvent(TraceEventType.Suspend, 10, "Switch includes ActivityTracing, this should appear")
ts.TraceEvent(TraceEventType.Critical, 11, "Switch includes Critical, this should appear")
ts.Flush()
ts.Close()
Console.WriteLine("Press any key to exit.")
Console.Read()
Catch e As Exception
' Catch any unexpected exception.
Console.WriteLine("Unexpected exception: " + e.ToString())
Console.Read()
End Try
End Sub
Public Shared Sub DisplayProperties(ByVal ts As TraceSource)
Console.WriteLine("TraceSource name = " + ts.Name)
Console.WriteLine("TraceSource switch level = " + ts.Switch.Level.ToString())
Console.WriteLine("TraceSource switch = " + ts.Switch.DisplayName.ToString())
Dim switches As SwitchAttribute() = SwitchAttribute.GetAll(GetType(TraceTest).Assembly)
Dim i As Integer
For i = 0 To switches.Length - 1
Console.WriteLine("Switch name = " + switches(i).SwitchName.ToString())
Console.WriteLine("Switch type = " + switches(i).SwitchType.ToString())
Next i
#If (ConfigFile) Then
' Get the custom attributes for the TraceSource.
Console.WriteLine("Number of custom trace source attributes = " + ts.Attributes.Count)
Dim de As DictionaryEntry
For Each de In ts.Attributes
Console.WriteLine("Custom trace source attribute = " + de.Key + " " + de.Value)
Next de
' Get the custom attributes for the trace source switch.
For Each de In ts.Switch.Attributes
Console.WriteLine("Custom switch attribute = " + de.Key + " " + de.Value)
Next de
#End If
Console.WriteLine("Number of listeners = " + ts.Listeners.Count.ToString())
Dim traceListener As TraceListener
For Each traceListener In ts.Listeners
Console.Write("TraceListener: " + traceListener.Name + vbTab)
' The following output can be used to update the configuration file.
Console.WriteLine("AssemblyQualifiedName = " + traceListener.GetType().AssemblyQualifiedName)
Next traceListener
End Sub
End Class
Remarks
The TraceSource class is used by applications to produce traces that can be associated with the application. TraceSource provides tracing methods that allow you to easily trace events, trace data, and issue informational traces.
In .NET Framework apps, trace output from TraceSource can be controlled by configuration file settings. The configuration file is located in the folder with the application executable and has the name of the application with the .config extension added. For example, the name of the configuration file for TraceSourceSample.exe is TraceSourceSample.exe.config. The configuration file can be used to specify where the trace information is to be sent and what levels of activity are to be traced. The following example shows the contents of a sample .NET Framework application configuration file.
<configuration>
<system.diagnostics>
<sources>
<source name="TraceTest" switchName="SourceSwitch"
switchType="System.Diagnostics.SourceSwitch" >
<listeners>
<add name="console" />
<remove name ="Default" />
</listeners>
</source>
</sources>
<switches>
<!-- You can set the level at which tracing is to occur -->
<add name="SourceSwitch" value="Warning" />
<!-- You can turn tracing off -->
<!--add name="SourceSwitch" value="Off" -->
</switches>
<sharedListeners>
<add name="console"
type="System.Diagnostics.ConsoleTraceListener"
initializeData="false"/>
</sharedListeners>
<trace autoflush="true" indentsize="4">
<listeners>
<add name="console" />
</listeners>
</trace>
</system.diagnostics>
</configuration>
The TraceSource class is identified by the name of a source, typically the name of the application. The trace messages coming from a particular component can be initiated by a particular trace source, allowing all messages coming from that component to be easily identified.
TraceSource defines tracing methods but does not actually provide any specific mechanism for generating and storing tracing data. The tracing data is produced by trace listeners, which are plug-ins that can be loaded by trace sources.
Note
You should not call the tracing methods during finalization. Doing so can result in an ObjectDisposedException being thrown.
You can customize the tracing output's target by adding or removing TraceListener instances to or from the collection stored in the TraceSource.Listeners property. By default, trace output is produced using an instance of the DefaultTraceListener class.
The preceding .NET Framework app configuration file example demonstrates removing the DefaultTraceListener and adding a ConsoleTraceListener to produce the trace output for the trace source. For more information, see <listeners> and <sharedListeners>.
Note
Adding a trace listener to the Listeners collection can cause an exception to be thrown while tracing, if a resource used by the trace listener is not available. The conditions and the exception thrown depend on the trace listener and cannot be enumerated in this topic. It may be useful to place calls to the TraceSource methods in try/catch blocks to detect and handle any exceptions from trace listeners.
The SourceSwitch class provides the means to dynamically control the tracing output. For .NET Framework apps, the preceding configuration file example shows how you can turn off tracing from a trace source and control the level at which tracing occurs. You can modify the value of the source switch without recompiling your application. For information on using the configuration file to set a switch, see Switch and How to: Create, Initialize and Configure Trace Switches.
Note
If you modify a configuration file while an application is executing, the application must be stopped and restarted or the Refresh method must be called before the new settings take effect.
The TraceEventType enumeration is used to define the event type of the trace message. Trace filters use the TraceEventType to determine if a trace listener should produce the trace message.
The trace listeners can optionally have an additional layer of filtering through a trace filter. If a trace listener has an associated filter, the listener calls the ShouldTrace method on that filter to determine whether or not to produce the trace information.
The trace listeners use the values of the Trace class properties Indent, IndentSize, and AutoFlush to format trace output. In .NET Framework apps, you can use configuration file attributes to set the Indent, IndentSize, and AutoFlush properties. The following example sets the AutoFlush property to false and the IndentSize property to 3.
<configuration>
<system.diagnostics>
<trace autoflush="false" indentsize="3" />
</system.diagnostics>
</configuration>
Constructors
| TraceSource(String, SourceLevels) |
Initializes a new instance of the TraceSource class, using the specified name for the source and the default source level at which tracing is to occur. |
| TraceSource(String) |
Initializes a new instance of the TraceSource class, using the specified name for the source. |
Properties
| Attributes |
Gets the custom switch attributes defined in the application configuration file. |
| DefaultLevel |
Gets the default level assigned in the constructor. |
| Listeners |
Gets the collection of trace listeners for the trace source. |
| Name |
Gets the name of the trace source. |
| Switch |
Gets or sets the source switch value. |
Methods
| Close() |
Closes all the trace listeners in the trace listener collection. |
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| Flush() |
Flushes all the trace listeners in the trace listener collection. |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetSupportedAttributes() |
Gets the custom attributes supported by the trace source. |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
| TraceData(TraceEventType, Int32, Object) |
Writes trace data to the trace listeners in the Listeners collection using the specified event type, event identifier, and trace data. |
| TraceData(TraceEventType, Int32, Object[]) |
Writes trace data to the trace listeners in the Listeners collection using the specified event type, event identifier, and trace data array. |
| TraceEvent(TraceEventType, Int32, String, Object[]) |
Writes a trace event to the trace listeners in the Listeners collection using the specified event type, event identifier, and argument array and format. |
| TraceEvent(TraceEventType, Int32, String) |
Writes a trace event message to the trace listeners in the Listeners collection using the specified event type, event identifier, and message. |
| TraceEvent(TraceEventType, Int32) |
Writes a trace event message to the trace listeners in the Listeners collection using the specified event type and event identifier. |
| TraceInformation(String, Object[]) |
Writes an informational message to the trace listeners in the Listeners collection using the specified object array and formatting information. |
| TraceInformation(String) |
Writes an informational message to the trace listeners in the Listeners collection using the specified message. |
| TraceTransfer(Int32, String, Guid) |
Writes a trace transfer message to the trace listeners in the Listeners collection using the specified numeric identifier, message, and related activity identifier. |
Events
| Initializing |
Occurs when a TraceSource needs to be initialized. |
Applies to
Thread Safety
This type is thread safe.
