/// <summary>
/// 执行委托并显示自定义等候窗体
/// </summary>
public static object RunDelegate(IWaitForm fmWait, Delegate del, params object[] args)
{
//利用AutoResetEvent.WaitOne的原子性，防止重入
if (!_areForWhole.WaitOne(0))
{
throw new WorkIsBusyException();
}
_isRunning = true;
try
{
if (fmWait == null)
{
throw new ArgumentNullException("fmWait");
}
if (del == null || del.GetInvocationList().Length != 1)
{
throw new ApplicationException("委托不能为空，且只能绑定1个方法！");
}
if (args == null)
{
throw new ArgumentNullException("args");
}
Reset();
_waitForm = fmWait;//需在开始异步任务前赋值，因为异步中可能用到
//更新上下文为UI线程上下文，因为如果在Main中Run，先前拿到的上下文也许时null，
//会导致在异步完成时用Post关闭窗体抛异常
_waitForm.Shown += (S, E) => _syncContext = SynchronizationContext.Current;
StartAsync(del, args);
Thread.Sleep(50); //给异步任务一点时间，如果在此时间内完成，就不弹窗
if (!_isCompleted)
{
//这里有可能出现异步先把wf关了的情况，所以要吃掉这种异常
try { _waitForm.ShowDialog(); }
catch (ObjectDisposedException) { }
}
//返回
if (Cancelled)
{
throw new WorkCancelledException();
}
if (_exception != null)
{
throw _exception;
}
return(_result);
}
finally
{
Release();
_areForWhole.Set();
_isRunning = false;
}
}
/// <summary>
/// 开始执行后台操作
/// </summary>
/// <param name="argument">要在DoWork事件处理程序中使用的参数</param>
/// <remarks>通过可选参数可以同时覆盖基类无参RunWorkerAsync，一石二鸟</remarks>
public new void RunWorkerAsync(object argument = null)
{
Form f;
activeForm = (f = Form.ActiveForm) != null && f.IsMdiContainer ? f.ActiveMdiChild : f;//记录当时的活动窗体
waitForm.CancelControlVisible = this.WorkerSupportsCancellation;
formClosed = false;
base.RunWorkerAsync(argument);
//这里要判断一下，极端情况下有可能还没等ShowDialog，窗体就已经被关闭了
if (!formClosed)
{
waitForm.ShowDialog();
}
}
/// <summary>
/// 开始执行后台操作
/// </summary>
/// <param name="argument">要在DoWork事件处理程序中使用的参数</param>
/// <remarks>通过可选参数可以同时覆盖基类无参RunWorkerAsync</remarks>
public new void RunWorkerAsync(object argument = null)
{
_waitForm.CancelControlVisible = this.WorkerSupportsCancellation;
_waitForm.CancelPending = false;//考虑该方法是可能重复进入的
base.RunWorkerAsync(argument);
//给异步任务一点时间，如果在此时间内完成，就不弹窗。
//不能用Sleep，因为异步任务完成是通过Post改IsBusy，
//Sleep会把Post也卡住，完了还是先走if，失去意义
DelayRun(50, () =>
{
if (IsBusy)
{
//这里有可能出现先把wf关了的情况，所以要吃掉这种异常
try { _waitForm.ShowDialog(); }
catch (ObjectDisposedException) { }
}
});
}
