異步后如何在主線程上運行代碼

Question

我的代碼只能在主線程上運行，但是在該代碼可以運行之前，我需要初始化一個對象。 無論如何，我可以強制異步代碼運行同步嗎？ 等待之后的函數是API調用，因此我無法直接修改它們。

    public partial class MainWindow : Window
    {
        private MustBeInit mbi;

        public MainWindow() {
            InitializeComponent();
            // async code that initializes mbi
            InitMbi(); 
            // mbi must be done at this point
            SomeCodeThatUsesMbi();
        }

        public async void InitMbi() {
            mbi = new MustBeInit();
            await mbi.DoSomethingAsync();
            await mbi.DoSomethingElseAsync();

            // is there any way i can run these two methods as not await and
            // run them synchronous?
        }

        public void SomeCodeThatUsesMbi() {
            DoSomethingWithMbi(mbi); // mbi cannot be null here
        }
    }

Answer 1

您不能在構造函數中使用await，但可以將整個內容放入預訂Window的Loaded事件的異步事件處理程序中：

public MainWindow()
{
   this.Loaded += async (s, e) => 
   {
        await InitMbi(); 
        // mbi must be done at this point
        SomeCodeThatUsesMbi();
   };

   InitializeComponent();
}

並且不要忘記將InitMbi()的返回值更改為Task ：

public async Task InitMbi()

Answer 2

 // is there any way i can run these two methods as not await and // run them synchronous? 

是的，只需在方法調用之前刪除await ：

public async void InitMbi() {
    mbi = new MustBeInit();
    mbi.DoSomethingAsync();
    mbi.DoSomethingElseAsync();

    // is there any way i can run these two methods as not await and
    // run them synchronous?
}

但是請注意，這將阻塞您的主線程！