c＃在异步方法返回后调用方法

Question

我希望只有在async方法返回后才执行Method2。 有没有办法做到这一点 ？

public class ViewModelBase
{

    public ICommand ClickCommand {get; private set;}

     public ViewModelBase()
     { 
         ClickCommand= new DelegateCommand<object>(myAsyncMethod);
     }

    private async void myAsyncMethod(object Param)
    {
        await Task.Run(()=> 
               {
                 // Do stuff
               });
    }


  private void Method2()
  {
    //Do things
  }

}

WPF

<ig:XamBusyIndicator DataContext="{Binding vm}" IsBusy="{Binding IsRunning}">
    <ContentControl Content="{Binding DisplayType}">
        <ContentControl.Style>
            <Style TargetType="ContentControl">
                <Setter Property="ContentTemplate">
                    <Setter.Value>
                        <DataTemplate></DataTemplate>
                    </Setter.Value>
                </Setter>
                <Style.Triggers>
                   <Trigger Property="Content"
                             Value="One">
                        <Setter Property="ContentTemplate">
                            <Setter.Value>
                                <DataTemplate>
                                    <igDP:XamDataGrid 
                                        DataContext="{Binding DataContext}"
                                        DataSource="{Binding UnDustedCollection}"></igDP:XamDataGrid>
                                </DataTemplate>
                            </Setter.Value>
                        </Setter>
                    </Trigger>
                    <Trigger Property="Content"
                             Value="Two">
                        <Setter Property="ContentTemplate">
                            <Setter.Value>
                                <DataTemplate>
                                    <igDP:XamDataGrid 
                                        DataContext="{Binding DataContext}"
                                        DataSource="{Binding DustedCollection}"></igDP:XamDataGrid>     
                                </DataTemplate>
                            </Setter.Value>
                        </Setter>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </ContentControl.Style>
    </ContentControl>
</ig:XamBusyIndicator>

Answer 1

只需在await之后调用您的方法或在另一个异步方法中包装myAsyncMethod，并在那里进行类似的操作。

private async void myAsyncMethod(object Param)
{
    await Task.Run(()=> 
           {
             // Do stuff. Not going to have safe access to UI elements
           });

    // await completed asynchronously.
    Method2(); // this method will have safe access to UI elements 
}

请注意，如果您需要与按钮状态更紧密地集成 - How does a toolbar button know to await?有一些想法（由Scott Chamberlain撰写suggested）。