CefSharp v62修改方法(支持.net4.0)

吐槽一下，博客园久了没有上，账号没了，重新申请一个.

cesharp v62版本，内核采用最新的cef 62，支持最新的grid布局. 由于官方的cefsharp 采用.net4.5.2开发.怎么办怎么办.我只能用.net4.0.没办法啊，自己拿源码修改兼容呗.

仔细分析源码发现：

1.net4.5.2 引入了 async/await 关键字. 这个其实国外大神已经有源码放出来了，我们把代码直接引入cefsharp 这个工程. 就可以直接在4.0里使用 async/await;

2.net4.5 对task api 做了扩展， 我们只需要在.net4.0实现一下对应的api.就可以了.

3. 源码里面用了很多4.5才有的gettypeinfo 扩展方法错误. 它返回的类型是typeinfo，不用管它，把gettypeinfo 删掉. 直接type 调用就可以了.

4. 对task静态方法的扩展，需要修改一下，静态方法的调用方式.

以上是要点.下面贴源码：

本段源码是对：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);
 }
 }
}

这段是对 task 的扩展

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;
 }
 }
}

把在c#内添加以上代码里， 遇到 task.run 的时候，替换成 taskex.run，遇到 task.delay 替换为taskex.delay.

还有报 gettypeinfo 这个错误的地方，删之就ok了。

以上这篇cefsharp v62修改方法(支持.net4.0)就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。