创建生成记录器
记录器提供一种方法，通过此方法可自定义生成的输出并显示消息、错误或警告以响应特定生成事件。 每个记录器作为 .NET 类实现，此类实现 Microsoft.Build.Framework.dll 程序集中定义的 ILogger 接口。
在实现记录器时，有两种方法可供选择：
直接实现 ILogger 接口。
从 Microsoft.Build.Utilities.dll 程序集中定义的帮助程序类 Logger 中派生类。 Logger 实现 ILogger，并提供了一些 ILogger 成员的默认实现代码。
本主题将介绍如何编写派生自 Logger 的简单记录器，并在控制台上显示用于响应特定生成事件的消息。
注册事件
记录器的目的是收集有关生成进度的信息（正如生成引擎所报告的信息），随后以有用的方式报告该信息。 所有记录器都必须重写 Initialize 方法，即记录器用于注册事件的位置。 在此示例中，记录器注册 TargetStarted、ProjectStarted 和 ProjectFinished 事件。
public class MySimpleLogger : Logger
{
public override void Initialize(Microsoft.Build.Framework.IEventSource eventSource)
{
//Register for the ProjectStarted, TargetStarted, and ProjectFinished events
eventSource.ProjectStarted += new ProjectStartedEventHandler(eventSource_ProjectStarted);
eventSource.TargetStarted += new TargetStartedEventHandler(eventSource_TargetStarted);
eventSource.ProjectFinished += new ProjectFinishedEventHandler(eventSource_ProjectFinished);
}
响应事件
记录器注册特定事件后，这些事件出现时，记录器需要处理这些事件。 对于 ProjectStarted 和 ProjectFinished 事件，记录器只写入一个短语，以及事件涉及的项目文件的名称。 记录器中的所有消息都写入到控制台窗口。
void eventSource_ProjectStarted(object sender, ProjectStartedEventArgs e)
{
Console.WriteLine("Project Started: " + e.ProjectFile);
}
void eventSource_ProjectFinished(object sender, ProjectFinishedEventArgs e)
{
Console.WriteLine("Project Finished: " + e.ProjectFile);
}
响应记录器详细信息值
在某些情况下，如果 MSBuild.exe -verbosity 开关包含特定值，建议仅记录事件信息。 在此示例中，仅当 verbosity 开关设置的 Verbosity 属性为 LoggerVerbosityDetailed 时，TargetStarted 事件处理程序才记录消息。
void eventSource_TargetStarted(object sender, TargetStartedEventArgs e)
{
if (Verbosity == LoggerVerbosity.Detailed)
{
Console.WriteLine("Target Started: " + e.TargetName);
}
}
指定记录器
将记录器编译到程序集后，你需要告诉 MSBuild 在生成过程中使用该记录器。 为此，可结合使用 -logger 开关和 MSBuild.exe。 有关可用于 MSBuild.exe 的开关的详细信息，请参阅命令行参考。
以下命令行生成项目 MyProject.csproj，并使用在 SimpleLogger.dll 中实现的记录器类。 -nologo 开关隐藏横幅和版权所有消息，-noconsolelogger 开关禁用默认的 MSBuild 控制台记录器。
MSBuild -nologo -noconsolelogger -logger:SimpleLogger.dll
以下命令行通过相同记录器生成项目，但是 Verbosity 级别为 Detailed。
MSBuild -nologo -noconsolelogger -logger:SimpleLogger.dll -verbosity:Detailed
示例 1
描述
下面的示例包含记录器的完整代码。
代码
using System;
using Microsoft.Build.Utilities;
using Microsoft.Build.Framework;
namespace SimpleLogger
{
public class MySimpleLogger : Logger
{
public override void Initialize(Microsoft.Build.Framework.IEventSource eventSource)
{
//Register for the ProjectStarted, TargetStarted, and ProjectFinished events
eventSource.ProjectStarted += new ProjectStartedEventHandler(eventSource_ProjectStarted);
eventSource.TargetStarted += new TargetStartedEventHandler(eventSource_TargetStarted);
eventSource.ProjectFinished += new ProjectFinishedEventHandler(eventSource_ProjectFinished);
}
void eventSource_ProjectStarted(object sender, ProjectStartedEventArgs e)
{
Console.WriteLine("Project Started: " + e.ProjectFile);
}
void eventSource_ProjectFinished(object sender, ProjectFinishedEventArgs e)
{
Console.WriteLine("Project Finished: " + e.ProjectFile);
}
void eventSource_TargetStarted(object sender, TargetStartedEventArgs e)
{
if (Verbosity == LoggerVerbosity.Detailed)
{
Console.WriteLine("Target Started: " + e.TargetName);
}
}
}
}
示例 2
描述
以下示例演示如何实现将日志写入到文件的记录器（而非在控制台窗口中显示记录器）。
代码
using System;
using System.IO;
using System.Security;
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
namespace MyLoggers
{
// This logger will derive from the Microsoft.Build.Utilities.Logger class,
// which provides it with getters and setters for Verbosity and Parameters,
// and a default empty Shutdown() implementation.
public class BasicFileLogger : Logger
{
/// <summary>
/// Initialize is guaranteed to be called by MSBuild at the start of the build
/// before any events are raised.
/// </summary>
public override void Initialize(IEventSource eventSource)
{
// The name of the log file should be passed as the first item in the
// "parameters" specification in the /logger switch. It is required
// to pass a log file to this logger. Other loggers may have zero or more than
// one parameters.
if (null == Parameters)
{
throw new LoggerException("Log file was not set.");
}
string[] parameters = Parameters.Split(';');
string logFile = parameters[0];
if (String.IsNullOrEmpty(logFile))
{
throw new LoggerException("Log file was not set.");
}
if (parameters.Length > 1)
{
throw new LoggerException("Too many parameters passed.");
}
try
{
// Open the file
this.streamWriter = new StreamWriter(logFile);
}
catch (Exception ex)
{
if
(
ex is UnauthorizedAccessException
|| ex is ArgumentNullException
|| ex is PathTooLongException
|| ex is DirectoryNotFoundException
|| ex is NotSupportedException
|| ex is ArgumentException
|| ex is SecurityException
|| ex is IOException
)
{
throw new LoggerException("Failed to create log file: " + ex.Message);
}
else
{
// Unexpected failure
throw;
}
}
// For brevity, we'll only register for certain event types. Loggers can also
// register to handle TargetStarted/Finished and other events.
eventSource.ProjectStarted += new ProjectStartedEventHandler(eventSource_ProjectStarted);
eventSource.TaskStarted += new TaskStartedEventHandler(eventSource_TaskStarted);
eventSource.MessageRaised += new BuildMessageEventHandler(eventSource_MessageRaised);
eventSource.WarningRaised += new BuildWarningEventHandler(eventSource_WarningRaised);
eventSource.ErrorRaised += new BuildErrorEventHandler(eventSource_ErrorRaised);
eventSource.ProjectFinished += new ProjectFinishedEventHandler(eventSource_ProjectFinished);
}
void eventSource_ErrorRaised(object sender, BuildErrorEventArgs e)
{
// BuildErrorEventArgs adds LineNumber, ColumnNumber, File, amongst other parameters
string line = String.Format(": ERROR {0}({1},{2}): ", e.File, e.LineNumber, e.ColumnNumber);
WriteLineWithSenderAndMessage(line, e);
}
void eventSource_WarningRaised(object sender, BuildWarningEventArgs e)
{
// BuildWarningEventArgs adds LineNumber, ColumnNumber, File, amongst other parameters
string line = String.Format(": Warning {0}({1},{2}): ", e.File, e.LineNumber, e.ColumnNumber);
WriteLineWithSenderAndMessage(line, e);
}
void eventSource_MessageRaised(object sender, BuildMessageEventArgs e)
{
// BuildMessageEventArgs adds Importance to BuildEventArgs
// Let's take account of the verbosity setting we've been passed in deciding whether to log the message
if ((e.Importance == MessageImportance.High && IsVerbosityAtLeast(LoggerVerbosity.Minimal))
|| (e.Importance == MessageImportance.Normal && IsVerbosityAtLeast(LoggerVerbosity.Normal))
|| (e.Importance == MessageImportance.Low && IsVerbosityAtLeast(LoggerVerbosity.Detailed))
)
{
WriteLineWithSenderAndMessage(String.Empty, e);
}
}
void eventSource_TaskStarted(object sender, TaskStartedEventArgs e)
{
// TaskStartedEventArgs adds ProjectFile, TaskFile, TaskName
// To keep this log clean, this logger will ignore these events.
}
void eventSource_ProjectStarted(object sender, ProjectStartedEventArgs e)
{
// ProjectStartedEventArgs adds ProjectFile, TargetNames
// Just the regular message string is good enough here, so just display that.
WriteLine(String.Empty, e);
indent++;
}
void eventSource_ProjectFinished(object sender, ProjectFinishedEventArgs e)
{
// The regular message string is good enough here too.
indent--;
WriteLine(String.Empty, e);
}
/// <summary>
/// Write a line to the log, adding the SenderName and Message
/// (these parameters are on all MSBuild event argument objects)
/// </summary>
private void WriteLineWithSenderAndMessage(string line, BuildEventArgs e)
{
if (0 == String.Compare(e.SenderName, "MSBuild", true /*ignore case*/))
{
// Well, if the sender name is MSBuild, let's leave it out for prettiness
WriteLine(line, e);
}
else
{
WriteLine(e.SenderName + ": " + line, e);
}
}
/// <summary>
/// Just write a line to the log
/// </summary>
private void WriteLine(string line, BuildEventArgs e)
{
for (int i = indent; i > 0; i--)
{
streamWriter.Write("\t");
}
streamWriter.WriteLine(line + e.Message);
}
/// <summary>
/// Shutdown() is guaranteed to be called by MSBuild at the end of the build, after all
/// events have been raised.
/// </summary>
public override void Shutdown()
{
// Done logging, let go of the file
streamWriter.Close();
}
private StreamWriter streamWriter;
private int indent;
}
}