C# Debug Timer

DebugTimer.cs

public class DebugTimer : IDisposable
{
  private readonly System.Diagnostics.Stopwatch _watch;
  private readonly string _blockName;
  
  /// <summary>
  /// Creates a timer.
  /// </summary>
  /// <param name="blockName">Name of the block that's being timed</param>
  public DebugTimer(string blockName)
  {
    _blockName = blockName;
    _watch = System.Diagnostics.Stopwatch.StartNew();
  }
  
  public void Dispose()
  {
    _watch.Stop();
    GC.SuppressFinalize(this);
    System.Diagnostics.Debug.WriteLine(_blockName + ": " + _watch.Elapsed.TotalSeconds + " seconds.");
  }

  ~DebugTimer()
  {
    throw new InvalidOperationException("Must Dispose() of all instances of " + this.GetType().FullName);
  }
}

Example.cs

public void Foo()
{
  using (new DebugTimer("Foo()"))
  {
    // Do work
  }
}

// In the Visual Studio Output window:
// Foo(): 1.2345 seconds.

If you're able to target C# 5/.Net 4.5 you can save yourself from potential refactoring issues falling out of sync by using the CallerMemberName Attribute.

public DebugTimer([System.Runtime.CompilerServices.CallerMemberName] string methodName = "") {
  _blockName = methodName;
  //...
}
/* ... */
public void Foo() {
  using (new DebugTimer()) {
    // Do work
  }
}

// In output window:
// Foo: 1.2345 seconds.

If you might need to call it in different places in the same method, you can extend the constructor to take an extra parameter to capture that info.