单击按钮时通知主线程

Question

我正在尝试创建一个这样的弹出窗口

// Create a Popup
var Pop = new Popup() { IsOpen = true };

// Create a StackPanel for the Buttons
var SPanel = new StackPanel() { Background = MainGrid.Background };

// Set the comment
var TxtBlockComment = new TextBlock { Margin = new Thickness(20, 5, 20, 5), Text = Obj.Comment };

// Set the value
var TxtBoxValue = new TextBox { Name = "MeasureValue" };
TxtBoxValue.KeyUp += (sender, e) => { VerifyKeyUp(sender, Measure); };

// Create the button
var ButtonFill = new Button { Content = Loader.GetString("ButtonAccept"), Margin = new Thickness(20, 5, 20, 5), Style = (Style)App.Current.Resources["TextButtonStyle"] };
ButtonFill.Click += (sender, e) => { Obj.Value = TxtBoxValue.Text; };

// Add the items to the StackPanel
SPanel.Children.Add(TxtBlockComment);
SPanel.Children.Add(TxtBoxValue);
SPanel.Children.Add(ButtonFill);

// Set the child on the popup
Pop.Child = SPanel;

我想在ButtonFill.Click事件执行后通知主线程，这样我就可以继续那个线程了

但是我该怎么做呢？

Answer 1

我假设您要问的是如何实现类似于FileOpenPicker.PickSingleFileAsync 的对话框行为。您可以使用TaskCompletionSource 创建等待任务：

private Task<string> OpenPopupAsync()
{
    var taskSource = new TaskCompletionSource<string>();

    // Create a Popup
    var Pop = new Popup() { IsOpen = true };

    // Create a StackPanel for the Buttons
    var SPanel = new StackPanel() { Background = MainGrid.Background };

    // Set the comment
    var TxtBlockComment = new TextBlock { Margin = new Thickness(20, 5, 20, 5), Text = Obj.Comment };

    // Set the value
    var TxtBoxValue = new TextBox { Name = "MeasureValue" };
    TxtBoxValue.KeyUp += (sender, e) => { VerifyKeyUp(sender, Measure); };

    // Create the button
    var ButtonFill = new Button { Content = Loader.GetString("ButtonAccept"), Margin = new Thickness(20, 5, 20, 5), Style = (Style)App.Current.Resources["TextButtonStyle"] };
    ButtonFill.Click += (sender, e) => { Pop.IsOpen = false; taskSource.SetResult(TxtBoxValue.Text); };

    // Add the items to the StackPanel
    SPanel.Children.Add(TxtBlockComment);
    SPanel.Children.Add(TxtBoxValue);
    SPanel.Children.Add(ButtonFill);

    // Set the child on the popup
    Pop.Child = SPanel;

    return taskSource.Task;
}

简而言之：

• 您创建了一个TaskCompletionSource 的实例
• 您将其Task 属性作为等待任务返回
• 当你想让调用方法继续时，你调用SetResult

在调用方法中，您只需 await 让方法在继续执行之前返回：

string result = await OpenPopupAsync();
// continue execution after the method returns

我还建议您查看Callisto's Flyout 控件，以更简单地实现弹出窗口。

Answer 2

在类和事件的开头放置一个布尔属性，将该布尔属性设置为 true。

ButtonFill.Click += (sender, e) => { ButtonClicked = true; Obj.Value = TxtBoxValue.Text; };