如何创建像CameraCaptureUI.CaptureFileAsync对话？(How to cr

我想创建一个库的行为就像CaptureFileAsync方法，即在一个方法调用它会打开一个全屏幕网页标准的后退导航，并返回结果给调用者。

我希望能够调用同样的方式CaptureFileAsync被称为：

var dialog = new Library.Dialog();
var result = await dialog.Show();

在Show方法我目前导航到自己的网页，并返回一个Task可以被调用者期待已久的：

public Task<string> Show()
{
    var task = new Task<string>(() => result);

    var frame = ((Window.Current.Content) as Frame);
    frame.Navigate(typeof(DialogPage));

    return task;
}

我称task.Start()时被关闭对话框（或者通过导航回到或证实通过按压按钮取消），其导致的结果将被返回到等待呼叫者。

问题是，当Frame.GoBack()被调用时，前一页的新实例被创建和获取的结果返回给未显示任何更老的实例。 这不是如何CaptureFileAsync工作原理：在其案件调用页面的同一个实例被保留。

我的问题是：我怎么能显示我的内容库页面，而不会影响帧导航和无意中导致调用页面的新实例被创建？

Answer 1:

你可以把你所有的UI上的弹出。

Answer 2:

看看PopupHelper 。

它使用抽象的弹出窗口全部ickines和动画需要照顾，禁止以控制等方式接入

Answer 3:

我有同样的问题，这就是我想出了：

XAML

<Grid x:Name="MainGrid" 
      Background="#7F000000">
    <Grid Width="480" Height="180" HorizontalAlignment="Center" VerticalAlignment="Center" Background="Black">
        <StackPanel>
            <TextBlock Text="Custom Capture!" Style="{StaticResource HeaderTextBlockStyle}" Margin="20"/>
            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
                <Button x:Name="SaveButton" Content="Save" HorizontalAlignment="Center" Click="CloseButton_Click"/>
                <Button x:Name="CloseButton" Content="Close" HorizontalAlignment="Center" Click="CloseButton_Click"/>
            </StackPanel>
        </StackPanel>
    </Grid>
</Grid>

控制

public sealed partial class CustomCaptureControl : UserControl
{
    private StorageFile file;
    private ManualResetEvent reset;
    private Popup _mainPopup;

    /// <summary>
    /// 
    /// </summary>
    public CustomCaptureControl()
    {
        this.InitializeComponent();

        Rect windowBounds = CoreWindow.GetForCurrentThread().Bounds;
        this.MainGrid.Width = windowBounds.Width;
        this.MainGrid.Height = windowBounds.Height;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <returns></returns>
    public async Task<StorageFile> ShowAsync()
    {
        StorageFile file = await Task.Run(() => this.GetFile());
        return file;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <returns></returns>
    private async Task<StorageFile> GetFile()
    {
        //Launch Popup in UI thread
        await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => 
        {
            this._mainPopup = new Popup();
            this._mainPopup.Child = this;
            this._mainPopup.IsOpen = true;
        });

        //Await user input
        await Task.Run(() => this.AwaitUserInput());

        return this.file;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <returns></returns>
    private Task AwaitUserInput()
    {
        return Task.Run(() =>
        {
            this.reset = new ManualResetEvent(false);
            WaitHandle.WaitAll(new WaitHandle[] { this.reset });
        });
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private async void CloseButton_Click(object sender, RoutedEventArgs e)
    {
        Uri fileURI = new Uri("ms-appx:///Assets/SomeFile.pdf");
        this.file = await StorageFile.GetFileFromApplicationUriAsync(fileURI);

        this.reset.Set();

        this._mainPopup.IsOpen = false;
        this._mainPopup = null;
    }
}

用法

CustomCaptureControl capture = new CustomCaptureControl();
StorageFile file = await capture.ShowAsync();

文章来源: How to create a dialog like CameraCaptureUI.CaptureFileAsync?