CefSharp v62修改方法(支持.net4.0)

namespace System.Threading.Tasks{ public static class TaskEx { public static TaskAwaiter GetAwaiter(this Task task) {  return new TaskAwaiter(task); } public static TaskAwaiter<T> GetAwaiter<T>(this Task<T> task) {  return new TaskAwaiter<T>(task); } } public struct TaskAwaiter : INotifyCompletion { readonly Task task; internal TaskAwaiter(Task task) {  this.task = task; } internal static TaskScheduler TaskScheduler {  get  {  if (SynchronizationContext.Current == null)   return TaskScheduler.Default;  else   return TaskScheduler.FromCurrentSynchronizationContext();  } } public bool IsCompleted {  get { return task.IsCompleted; } } public void OnCompleted(Action continuation) {  this.task.ContinueWith(  delegate (Task task) {   continuation();  }, TaskAwaiter.TaskScheduler); } public void GetResult() {  try  {  task.Wait();  }  catch (AggregateException ex)  {  throw ex.InnerExceptions[0];  } } } public struct TaskAwaiter<T> : INotifyCompletion { readonly Task<T> task; internal TaskAwaiter(Task<T> task) {  this.task = task; } public bool IsCompleted {  get { return task.IsCompleted; } } public void OnCompleted(Action continuation) {  this.task.ContinueWith(  delegate (Task<T> task) {   continuation();  }, TaskAwaiter.TaskScheduler); } public T GetResult() {  try  {  return task.Result;  }  catch (AggregateException ex)  {  throw ex.InnerExceptions[0];  } } }}namespace System.Runtime.CompilerServices{ public interface INotifyCompletion { void OnCompleted(Action continuation); } public interface ICriticalNotifyCompletion : INotifyCompletion { [SecurityCritical] void UnsafeOnCompleted(Action continuation); } public interface IAsyncStateMachine { void MoveNext(); void SetStateMachine(IAsyncStateMachine stateMachine); } public struct AsyncVoidMethodBuilder { public static AsyncVoidMethodBuilder Create() {  return new AsyncVoidMethodBuilder(); } public void SetException(Exception exception) {  throw exception; } public void SetResult() { } public void SetStateMachine(IAsyncStateMachine stateMachine) {  // Should not get called as we don't implement the optimization that this method is used for.  throw new NotImplementedException(); } public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine {  stateMachine.MoveNext(); } public void AwaitOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : INotifyCompletion where TStateMachine : IAsyncStateMachine {  awaiter.OnCompleted(stateMachine.MoveNext); } public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : ICriticalNotifyCompletion where TStateMachine : IAsyncStateMachine {  awaiter.OnCompleted(stateMachine.MoveNext); } } public struct AsyncTaskMethodBuilder { TaskCompletionSource<object> tcs; public Task Task { get { return tcs.Task; } } public static AsyncTaskMethodBuilder Create() {  AsyncTaskMethodBuilder b;  b.tcs = new TaskCompletionSource<object>();  return b; } public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine {  stateMachine.MoveNext(); } public void SetStateMachine(IAsyncStateMachine stateMachine) {  // Should not get called as we don't implement the optimization that this method is used for.  throw new NotImplementedException(); } public void AwaitOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : INotifyCompletion where TStateMachine : IAsyncStateMachine {  awaiter.OnCompleted(stateMachine.MoveNext); } public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : ICriticalNotifyCompletion where TStateMachine : IAsyncStateMachine {  awaiter.OnCompleted(stateMachine.MoveNext); } public void SetResult() {  tcs.SetResult(null); } public void SetException(Exception exception) {  tcs.SetException(exception); } } public struct AsyncTaskMethodBuilder<T> { TaskCompletionSource<T> tcs; public Task<T> Task { get { return tcs.Task; } } public static AsyncTaskMethodBuilder<T> Create() {  AsyncTaskMethodBuilder<T> b;  b.tcs = new TaskCompletionSource<T>();  return b; } public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine {  stateMachine.MoveNext(); } public void SetStateMachine(IAsyncStateMachine stateMachine) {  // Should not get called as we don't implement the optimization that this method is used for.  throw new NotImplementedException(); } public void AwaitOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : INotifyCompletion where TStateMachine : IAsyncStateMachine {  awaiter.OnCompleted(stateMachine.MoveNext); } public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : ICriticalNotifyCompletion where TStateMachine : IAsyncStateMachine {  AwaitOnCompleted(ref awaiter, ref stateMachine); } public void SetResult(T result) {  tcs.SetResult(result); } public void SetException(Exception exception) {  tcs.SetException(exception); } }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading;using System.Threading.Tasks;namespace CefSharp{ public class TaskEx { public static Task<T> FromResult<T>(T t) {  return Task.Factory.StartNew<T>(() => t); } public static Task Run(Action action) {  var tcs = new TaskCompletionSource<object>();  new Thread(() => {   try   {   action();   tcs.SetResult(null);   }   catch (Exception ex)   {   tcs.SetException(ex);   }  })  { IsBackground = true }.Start();  return tcs.Task; } public static Task<TResult> Run<TResult>(Func<TResult> function) {  var tcs = new TaskCompletionSource<TResult>();  new Thread(() =>  {   try   {   tcs.SetResult(function());   }   catch (Exception ex)   {   tcs.SetException(ex);   }  })  { IsBackground = true }.Start();  return tcs.Task; } public static Task Delay(int milliseconds) {  var tcs = new TaskCompletionSource<object>();  var timer = new System.Timers.Timer(milliseconds) { AutoReset = false };  timer.Elapsed += delegate { timer.Dispose(); tcs.SetResult(null); };  timer.Start();  return tcs.Task; } }}