Question

当我按下按钮时，appbarbutton和滑块不会隐藏。当我调试我可以确认已通知“崩溃或可见”。不知道我做了什么错。请帮助解决问题。

我正在为xbox one构建通用Windows平台（UWP）。

<Page
x:Class="AvProStreaming.MainPage"
IsTabStop="false"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:AvProStreaming"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="RosyBrown">

<SwapChainPanel x:Name="DXSwapChainPanel">
    <Grid x:Name="ExtendedSplashGrid" Background="#FFFFFF">
        <Image x:Name="ExtendedSplashImage" Source="Assets/SplashScreen.png" VerticalAlignment="Center" HorizontalAlignment="Center"/>
    </Grid>

    <Slider x:Name="slider" Background="Cyan" HorizontalAlignment="Stretch" Margin="10,444,10,0" VerticalAlignment="Top" Height="46"
          Visibility="{Binding IsHide}" />

    <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Bottom" Height="150" >

        <AppBarButton Foreground="Cyan" Icon="Back" Name="Backward" Label="Back" Click="MenuItem_Selected" 
                     Visibility="{Binding IsHide}" Margin="30"/>
        <AppBarButton Foreground="Cyan" Icon="Play" Name="Play" Label="Play" Click="MenuItem_Selected" 
                     Visibility="Collapsed" Margin="30"/>
        <AppBarButton Foreground="Cyan" Icon="Pause" Name="Pause" Label="Pause" Click="MenuItem_Selected" 
                     Visibility="{Binding IsHide}" Margin="30"/>
        <AppBarButton Foreground="Cyan" Icon="Forward" x:Name="Forward" Label="Forward" Click="MenuItem_Selected" 
                     Visibility="{Binding IsHide}" Margin="30"/>

    </StackPanel>

</SwapChainPanel>

public sealed partial class MainPage : Page, INotifyPropertyChanged
{
    private WinRTBridge.WinRTBridge _bridge;

    private SplashScreen splash;
    private Rect splashImageRect;
    private WindowSizeChangedEventHandler onResizeHandler;

    private Visibility _IsHide;
    public Visibility IsHide
    {
        get { return _IsHide; }
        set
        {
            _IsHide = value;
            OnPropertyChanged("IsHide");
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged(string property)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(property));
        }
    }......

private void MainPage_KeyDown(object sender, KeyRoutedEventArgs e)
    {
        Debug.WriteLine("Keydown");

        if (!App.IsXbox())
            e.Handled = true;

       if (e.OriginalKey == Windows.System.VirtualKey.GamepadMenu)
        {
            Debug.WriteLine("GamepadView button clicked");
            IsHide = Visibility.Collapsed;
        }
    }

Answer 1

没有显式指定源对象的绑定要求目标元素的DataContext（或其父元素之一）绑定到拥有绑定源属性的类的实例。

因此，将DataContext = this;添加到构造函数中可以解决问题。

Xaml UWP按钮隐藏/显示无法使用INotifyPropertyChanged

1 个答案: