吐槽一下，博客園久了沒有上，賬號沒了，重新申請一個.

cesharp v62版本，內(nèi)核采用最新的Cef 62，支持最新的Grid布局. 由于官方的cefsharp 采用.net4.5.2開發(fā).怎么辦怎么辦.我只能用.net4.0.沒辦法啊，自己拿源碼修改兼容唄.

仔細分析源碼發(fā)現(xiàn)：

1.net4.5.2 引入了 async/await 關(guān)鍵字. 這個其實國外大神已經(jīng)有源碼放出來了，我們把代碼直接引入cefsharp 這個工程. 就可以直接在4.0里使用 async/await;

2.net4.5 對task api 做了擴展， 我們只需要在.net4.0實現(xiàn)一下對應(yīng)的api.就可以了.

3. 源碼里面用了很多4.5才有的GetTypeInfo 擴展方法錯誤. 它返回的類型是typeinfo，不用管它，把GetTypeInfo 刪掉. 直接Type 調(diào)用就可以了.

4. 對Task靜態(tài)方法的擴展，需要修改一下，靜態(tài)方法的調(diào)用方式.

以上是要點.下面貼源碼：

本段源碼是對：async/await的支持：

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); } }}