Question

我正在尝试在我的应用程序中“注入”自定义跟踪方法。

我希望尽可能优雅，不需要修改现有的大部分代码，并且可以轻松启用/禁用它。

我能想到的一个解决方案是创建一个自定义public class MethodSnifferAttribute : Attribute { private Stopwatch sw = null; public void BeforeExecution() { sw = new Stopwatch(); sw.Start(); } public void ExecutionEnd() { sw.Stop(); LoggerManager.Logger.Log("Execution time: " + sw.ElapsedMilliseconds); } } public class MyClass { [MethodSniffer] public void Function() { // do a long task } }，我将它附加到我想要跟踪的方法上。

基本理念：

.NET

是否有任何现有的nav-tab属性为调用/结束方法提供回调？

Answer 1

除非您手动调用，否则不会调用

属性的方法。有一些安全属性可以由CLR调用，但这超出了这个问题的主题，无论如何都不会有用。

有一些技术可以在不同的级别重写代码。源代码编织，IL编织等。

您需要查看某种方法来修改IL并重写它以便执行计时。别担心，你不必写所有这些。人们已经做到了。例如，您可以使用PostSharp。

这里有article，提供了一个示例

[Serializable]
[DebuggerStepThrough]
[AttributeUsage(AttributeTargets.Method)]
public sealed class LogExecutionTimeAttribute : OnMethodInvocationAspect
{
    private static readonly ILog Log = LogManager.GetLogger(typeof(LogExecutionTimeAttribute));

    // If no threshold is provided, then just log the execution time as debug
    public LogExecutionTimeAttribute() : this (int.MaxValue, true)
    {
    }
    // If a threshold is provided, then just flag warnning when threshold's exceeded
    public LogExecutionTimeAttribute(int threshold) : this (threshold, false)
    {
    }
    // Greediest constructor
    public LogExecutionTimeAttribute(int threshold, bool logDebug)
    {
        Threshold = threshold;
        LogDebug = logDebug;
    }

    public int Threshold { get; set; }
    public bool LogDebug { get; set; }

    // Record time spent executing the method
    public override void OnInvocation(MethodInvocationEventArgs eventArgs)
    {
        var sw = Stopwatch.StartNew();
        eventArgs.Proceed();
        sw.Stop();
        var timeSpent = sw.ElapsedMilliseconds;

        if (LogDebug)
        {
            Log.DebugFormat(
                "Method [{0}{1}] took [{2}] milliseconds to execute",
                eventArgs.Method.DeclaringType.Name,
                eventArgs.Method.Name,
                timeSpent);
        }

        if (timeSpent > Threshold)
        {
            Log.WarnFormat(
                "Method [{0}{1}] was expected to finish within [{2}] milliseconds, but took [{3}] instead!",
                eventArgs.Method.DeclaringType.Name,
                eventArgs.Method.Name,
                Threshold,
                timeSpent);
       }
}

注意：我已修改文章中的示例以使用StopWatch而不是DateTime，因为DateTime并不准确。

Answer 2

您可以使用PostSharp（可用作NuGet包）轻松跟踪方法执行时间。执行该操作的自定义方法级属性的代码（取自here）：

  [Serializable]
  [DebuggerStepThrough]
  [AttributeUsage(AttributeTargets.Method)]
  public sealed class LogExecutionTimeAttribute : OnMethodInvocationAspect
  {
  private static readonly ILog Log = LogManager.GetLogger(typeof(LogExecutionTimeAttribute));

  // If no threshold is provided, then just log the execution time as debug
  public LogExecutionTimeAttribute() : this (int.MaxValue, true)
  {
  }
  // If a threshold is provided, then just flag warnning when threshold's exceeded
  public LogExecutionTimeAttribute(int threshold) : this (threshold, false)
  {
  }
  // Greediest constructor
  public LogExecutionTimeAttribute(int threshold, bool logDebug)
  {
    Threshold = threshold;
    LogDebug = logDebug;
  }

  public int Threshold { get; set; }
  public bool LogDebug { get; set; }

  // Record time spent executing the method
  public override void OnInvocation(MethodInvocationEventArgs eventArgs)
  {
    var start = DateTime.Now;
    eventArgs.Proceed();
    var timeSpent = (DateTime.Now - start).TotalMilliseconds;

    if (LogDebug)
    {
    Log.DebugFormat(
    "Method [{0}{1}] took [{2}] milliseconds to execute",
    eventArgs.Method.DeclaringType.Name,
    eventArgs.Method.Name,
    timeSpent);
    }

    if (timeSpent > Threshold)
    {
    Log.WarnFormat(
    "Method [{0}{1}] was expected to finish within [{2}] milliseconds, but took [{3}] instead!",
    eventArgs.Method.DeclaringType.Name,
    eventArgs.Method.Name,
    Threshold,
    timeSpent);
    }
  }

跟踪方法执行时间

2 个答案: