我有一个包含照片和说明的flipview。我想要点击photo1，然后descbox1不可见。如果再次点击photo1，则会出现descbox1。
XAML：
<FlipView x:Name="narrowFlipview"
ItemsSource="{Binding Group.Items}"
SelectedItem="{Binding Item, Mode=TwoWay}"
Foreground="{x:Null}"
Visibility="Collapsed">
<FlipView.ItemTemplate>
<DataTemplate>
<Grid x:Name="content1"
Margin="0,0,0,0">
<Image x:Name="photo1"
Margin="0,0,10,10"
Source="{Binding ImagePath}"
Tapped="photo_Tapped" />
<Grid x:Name="detail"
VerticalAlignment="Bottom"
Height="200">
<Grid.RowDefinitions>
<RowDefinition Height="auto" />
<RowDefinition Height="auto" />
</Grid.RowDefinitions>
<Button x:Name="hideBtn"
Height="50"
Width="50"
Margin="0,0,5,0"
HorizontalAlignment="Right"
VerticalAlignment="Bottom"
Grid.Row="0"
Click="hideBtn_Click">
<Button.Background>
<ImageBrush Stretch="Uniform"
ImageSource="images/media/ikon-56-app-white-down.png" />
</Button.Background>
</Button>
<Button x:Name="detailBtn"
Height="50"
Width="50"
Margin="0,0,5,0"
HorizontalAlignment="Right"
VerticalContentAlignment="Bottom"
Grid.Row="1"
Visibility="Collapsed"
Click="detailBtn_Click">
<Button.Background>
<ImageBrush Stretch="Uniform"
ImageSource="images/media/ikon-56-app-white-up.png" />
</Button.Background>
</Button>
<ScrollViewer x:Name="descBox1"
Grid.Row="1"
Height="150"
Background="#95000000"
VerticalScrollBarVisibility="Auto">
<TextBlock x:Name="descriptionText1"
Text="{Binding Description}"
Margin="20,20,20,0"
TextWrapping="Wrap"
TextAlignment="Justify"
VerticalAlignment="Top"
Height="auto"
Foreground="White"
FontSize="21" />
</ScrollViewer>
</Grid>
</Grid>
</DataTemplate>
</FlipView.ItemTemplate>
</FlipView>
我尝试使用以下代码：
private DependencyObject FindChildControl<T>(DependencyObject control, string ctrlName)
{
int childNumber = VisualTreeHelper.GetChildrenCount(control);
for (int i = 0; i < childNumber; i++)
{
DependencyObject child = VisualTreeHelper.GetChild(control, i);
FrameworkElement fe = child as FrameworkElement;
// Not a framework element or is null
if (fe == null) return null;
if (child is T && fe.Name == ctrlName)
{
// Found the control so return
return child;
}
else
{
// Not found it - search children
DependencyObject nextLevel = FindChildControl<T>(child, ctrlName);
if (nextLevel != null)
return nextLevel;
}
}
return null;
}
public bool _IsOn;
public bool IsOn
{
get
{
return _IsOn;
}
set
{
_IsOn = value;
}
}
private void photo_Tapped(object sender, TappedRoutedEventArgs e)
{
ScrollViewer descBox1 = FindChildControl<ScrollViewer>(this, "descBox1") as ScrollViewer;
Button hideBtn = FindChildControl<Button>(this, "hideBtn") as Button;
Button detailBtn = FindChildControl<Button>(this, "detaiBtn") as Button;
IsOn = !IsOn;
if (_IsOn)
{
descBox1.Visibility = Visibility.Collapsed;
hideBtn.Visibility = Visibility.Collapsed;
detailBtn.Visibility = Visibility.Visible;
}
else
{
descBox1.Visibility = Visibility.Visible;
hideBtn.Visibility = Visibility.Visible;
detailBtn.Visibility = Visibility.Collapsed;
}
}
但是当我点击photo1时，descBox1不会崩溃，hiddenBtn不会崩溃，detailBtn将不可见。 如何处理？
答案 0 :(得分：0)
根据您的要求，我认为在这里使用Binding来控制这些控件的可见性将是一个更简单的解决方案。例如，我们可以利用Tag property。
参考备注：
标记属性的方案是在所有FrameworkElement.Tag property类上提供通用属性，这些类支持自身的数据绑定，动画和样式，但属性值没有平台子系统的任何隐含含义，如布局，应用程序模型，文本，输入等。
在这里，我们可以使用此属性存储Visibility，在其他控件中，将Visibility属性绑定到此属性，如：
<ScrollViewer x:Name="descBox1"
Grid.Row="1"
Height="150"
Background="#95000000"
VerticalScrollBarVisibility="Auto"
Visibility="{Binding Tag, ElementName=photo1}">
<TextBlock x:Name="descriptionText1"
Height="auto"
Margin="20,20,20,0"
VerticalAlignment="Top"
FontSize="21"
Foreground="White"
Text="{Binding Description}"
TextAlignment="Justify"
TextWrapping="Wrap" />
</ScrollViewer>
然后在photo_Tapped方法中，我们可以更改Tag的值来控制“descBox1”的可见性。
private void photo_Tapped(object sender, TappedRoutedEventArgs e)
{
var tag = (sender as Image)?.Tag?.ToString();
//if we didn't set Tag in Image, its value should be null and descBox1 will be Visible
if (string.IsNullOrEmpty(tag) || tag.Equals("Visible"))
{
(sender as Image).Tag = Visibility.Collapsed;
}
else
{
(sender as Image).Tag = Visibility.Visible;
}
}
“hiddenBtn”类似，我们只需要将Mode的{{1}}设置为Binding，这样当我们更改其可见性时，“descBox1”和“detailBtn”将会也会自动更改其可见性。
TwoMay<Button x:Name="hideBtn"
Grid.Row="0"
Width="50"
Height="50"
Margin="0,0,5,0"
HorizontalAlignment="Right"
VerticalAlignment="Bottom"
Click="hideBtn_Click"
Visibility="{Binding Tag, ElementName=photo1, Mode=TwoWay}">
<Button.Background>
<ImageBrush ImageSource="images/media/ikon-56-app-white-down.png" Stretch="Uniform" />
</Button.Background>
</Button>
“detailBtn”与“hiddenBtn”相同，但其可见性与“hiddenBtn”相反。所以我们需要private void hideBtn_Click(object sender, RoutedEventArgs e)
{
ChangeButtonVisibility(sender);
}
private void ChangeButtonVisibility(object sender)
{
var visibility = (sender as Button)?.Visibility;
if (visibility.Equals(Visibility.Visible))
{
(sender as Button).Visibility = Visibility.Collapsed;
}
else
{
(sender as Button).Visibility = Visibility.Visible;
}
}
如下：
InvertedVisibilityConverter在“detailBtn”中，设置public class InvertedVisibilityConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, string language)
{
return InvertedVisibility(value);
}
public object ConvertBack(object value, Type targetType, object parameter, string language)
{
return InvertedVisibility(value);
}
private object InvertedVisibility(object value)
{
var visibility = value?.ToString();
if (string.IsNullOrEmpty(visibility) || visibility.Equals("Visible"))
{
return Visibility.Collapsed;
}
else
{
return Visibility.Visible;
}
}
}
如下：
Binding<Button x:Name="detailBtn"
Grid.Row="1"
Width="50"
Height="50"
Margin="0,0,5,0"
HorizontalAlignment="Right"
VerticalContentAlignment="Bottom"
Click="detailBtn_Click"
Visibility="{Binding Tag, ElementName=photo1, Mode=TwoWay, Converter={StaticResource InvertedVisibilityConverter}}">
<Button.Background>
<ImageBrush ImageSource="images/media/ikon-56-app-white-up.png" Stretch="Uniform" />
</Button.Background>
</Button>
更新：为了使所有private void detailBtn_Click(object sender, RoutedEventArgs e)
{
ChangeButtonVisibility(sender);
}
中的可见性具有相同的行为，我们需要一个可以“全局”存储可见性的依赖属性。因此，我们可以使用FlipViewItem的{{1}}属性而不是FlipView的{{1}}属性，并在Tag中设置Image，如下所示：< / p>
Tag在此之后，所有Image的{{1}}将具有相同的值。由于这是一种双向绑定，当我们更改一个Binding的{{1}}值时，它会自动更改<Image x:Name="photo1"
Margin="0,0,10,10"
Source="{Binding ImagePath}"
Tag="{Binding Tag, ElementName=narrowFlipview, Mode=TwoWay}"
Tapped="photo_Tapped" />
的值，然后传播到所有其他Image }。
在“descBox1”，“hiddenBtn”和“detailBtn”等其他控件中，我们还可以将Tag从Image更改为Tag更改为FlipView.Tag。以“detailBtn”为例：
Images并且无需更改代码隐藏，在XAML中编辑Binding之后，它应该能够实现您想要的效果。