查找 .NET 4.5 进度源代码

以下是 ILSpy 的输出：

using System;
using System.Runtime;
using System.Threading;
namespace System
{
    [__DynamicallyInvokable]
    public class Progress<T> : IProgress<T>
    {
        private readonly SynchronizationContext m_synchronizationContext;
        private readonly Action<T> m_handler;
        private readonly SendOrPostCallback m_invokeHandlers;
        [__DynamicallyInvokable]
        public event EventHandler<T> ProgressChanged
        {
            [__DynamicallyInvokable]
            add
            {
                EventHandler<T> eventHandler = this.ProgressChanged;
                EventHandler<T> eventHandler2;
                do
                {
                    eventHandler2 = eventHandler;
                    EventHandler<T> value2 = (EventHandler<T>)Delegate.Combine(eventHandler2, value);
                    eventHandler = Interlocked.CompareExchange<EventHandler<T>>(ref this.ProgressChanged, value2, eventHandler2);
                }
                while (eventHandler != eventHandler2);
            }
            [__DynamicallyInvokable]
            remove
            {
                EventHandler<T> eventHandler = this.ProgressChanged;
                EventHandler<T> eventHandler2;
                do
                {
                    eventHandler2 = eventHandler;
                    EventHandler<T> value2 = (EventHandler<T>)Delegate.Remove(eventHandler2, value);
                    eventHandler = Interlocked.CompareExchange<EventHandler<T>>(ref this.ProgressChanged, value2, eventHandler2);
                }
                while (eventHandler != eventHandler2);
            }
        }
        [__DynamicallyInvokable]
        public Progress()
        {
            this.m_synchronizationContext = (SynchronizationContext.CurrentNoFlow ?? ProgressStatics.DefaultContext);
            this.m_invokeHandlers = new SendOrPostCallback(this.InvokeHandlers);
        }
        [__DynamicallyInvokable]
        public Progress(Action<T> handler) : this()
        {
            if (handler == null)
            {
                throw new ArgumentNullException("handler");
            }
            this.m_handler = handler;
        }
        [__DynamicallyInvokable]
        protected virtual void OnReport(T value)
        {
            Action<T> handler = this.m_handler;
            EventHandler<T> progressChanged = this.ProgressChanged;
            if (handler != null || progressChanged != null)
            {
                this.m_synchronizationContext.Post(this.m_invokeHandlers, value);
            }
        }
        [__DynamicallyInvokable, TargetedPatchingOptOut("Performance critical to inline this type of method across NGen image boundaries")]
        void IProgress<T>.Report(T value)
        {
            this.OnReport(value);
        }
        private void InvokeHandlers(object state)
        {
            T t = (T)((object)state);
            Action<T> handler = this.m_handler;
            EventHandler<T> progressChanged = this.ProgressChanged;
            if (handler != null)
            {
                handler(t);
            }
            if (progressChanged != null)
            {
                progressChanged(this, t);
            }
        }
    }
}

下载.NET Framework version 4.5并将其安装在您的 PC 上。然后获取类似dotPeek的副本，并使用它来查看Progress的源代码。

http://www.microsoft.com/en-us/download/details.aspx?id=8483

http://www.jetbrains.com/decompiler/

如果您对原始源代码感兴趣，Microsoft 已在互联网上提供。进度类的源代码可以在这里找到：

https://referencesource.microsoft.com/#mscorlib/system/progress.cs

源代码取自 ReSharper Decompiler：

// Decompiled with JetBrains decompiler
// Type: System.Progress`1
// Assembly: mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
// MVID: 85AB3664-E4CA-41A0-86E3-96342ED95AAA
// Assembly location: C:'Windows'Microsoft.NET'Framework'v4.0.30319'mscorlib.dll
using System.Threading;
namespace System
{
  /// <summary>Provides an <see cref="T:System.IProgress`1" /> that invokes callbacks for each reported progress value.</summary>
  /// <typeparam name="T">Specifies the type of the progress report value.</typeparam>
  [__DynamicallyInvokable]
  public class Progress<T> : IProgress<T>
  {
    private readonly SynchronizationContext m_synchronizationContext;
    private readonly Action<T> m_handler;
    private readonly SendOrPostCallback m_invokeHandlers;
    /// <summary>Raised for each reported progress value.</summary>
    [__DynamicallyInvokable]
    public event EventHandler<T> ProgressChanged;
    /// <summary>Initializes the <see cref="T:System.Progress`1" /> object.</summary>
    [__DynamicallyInvokable]
    public Progress()
    {
      this.m_synchronizationContext = SynchronizationContext.CurrentNoFlow ?? ProgressStatics.DefaultContext;
      this.m_invokeHandlers = new SendOrPostCallback(this.InvokeHandlers);
    }
    /// <summary>Initializes the <see cref="T:System.Progress`1" /> object with the specified callback.</summary>
    /// <param name="handler">A handler to invoke for each reported progress value. This handler will be invoked in addition to any delegates registered with the <see cref="E:System.Progress`1.ProgressChanged" /> event. Depending on the <see cref="T:System.Threading.SynchronizationContext" /> instance captured by the <see cref="T:System.Progress`1" /> at construction, it is possible that this handler instance could be invoked concurrently with itself.</param>
    [__DynamicallyInvokable]
    public Progress(Action<T> handler)
      : this()
    {
      if (handler == null)
        throw new ArgumentNullException("handler");
      this.m_handler = handler;
    }
    /// <summary>Reports a progress change.</summary>
    /// <param name="value">The value of the updated progress.</param>
    [__DynamicallyInvokable]
    protected virtual void OnReport(T value)
    {
      // ISSUE: reference to a compiler-generated field
      if (this.m_handler == null && this.ProgressChanged == null)
        return;
      this.m_synchronizationContext.Post(this.m_invokeHandlers, (object) value);
    }
    [__DynamicallyInvokable]
    void IProgress<T>.Report(T value)
    {
      this.OnReport(value);
    }
    private void InvokeHandlers(object state)
    {
      T e = (T) state;
      Action<T> handler = this.m_handler;
      // ISSUE: reference to a compiler-generated field
      EventHandler<T> progressChanged = this.ProgressChanged;
      if (handler != null)
        handler(e);
      if (progressChanged == null)
        return;
      progressChanged((object) this, e);
    }
  }
}