问题描述
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。
I have a flipview which contains photos and descriptions. I want when photo1 be tapped, then descbox1 not visible. And if photo1 be tapped again, then descbox1 will appear.
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？
But when I tap photo1, descBox1 would not collapse, hiddenBtn would not collapsed, detailBtn would not visible.How to handle it?
推荐答案
根据您的要求，我认为使用绑定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。
According to your requirement, I'd think using Binding here to control these control's visibility would be a simpler solution. For example, we can take advantage of the Tag property.
：
Ref Remarks in FrameworkElement.Tag property:
这里我们可以使用这个属性来存储可见性，在其他控件中，将<可见性属性绑定到此属性，如：
Here we can use this property to store the Visibility and in other controls, bind ther Visibility property to this property like:
<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，我们可以更改标记用于控制descBox1可见性的值。
Then in photo_Tapped method, we can change Tag's value to control the visibility of "descBox1".
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，我们只需要设置 Binding 的模式到 TwoMay ，这样当我们更改其可见性，descBox1和detailBtn也会自动更改其可见性。
"hiddenBtn" is similar, we only need to set the Mode of the Binding to TwoMay, so that when we change its visibility, "descBox1" and "detailBtn" will also change their visibility automatically.
<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>
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;
}
}
detailBtn与hiddenBtn相同，但其可见性与hiddenBtn相反。所以我们需要一个 InvertedVisibilityConverter ，如下所示：
"detailBtn" is the same as "hiddenBtn", but its visibility is opposite to "hiddenBtn". So we will need a InvertedVisibilityConverter like following:
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;
}
}
}
在detailBtn中，设置绑定如下：
And in "detailBtn", setting Binding like following:
<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>
private void detailBtn_Click(object sender, RoutedEventArgs e)
{
ChangeButtonVisibility(sender);
}
更新： 为了使所有 FlipViewItem 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。所以我们可以使用 FlipView 的标记属性而不是 Image 的标记属性，并在图像中设置绑定如下所示：
Update: To make the visibilities in all FlipViewItems have the same behavior, we need a dependence property that can store the visibility "globally". So we can use FlipView's Tag property instead of Image's Tag property and in Image set the Binding like following:
<Image x:Name="photo1"
Margin="0,0,10,10"
Source="{Binding ImagePath}"
Tag="{Binding Tag, ElementName=narrowFlipview, Mode=TwoWay}"
Tapped="photo_Tapped" />
此后所有图片的标记将具有相同的值。由于这是一个双向绑定，当我们更改一个 Image 的标记值时，它会自动更改 FlipView.Tag 的值，然后传播到所有其他图像。
After this all Image's Tag will have the same value. And as this is a two-way binding, when we change one Image's Tag value, it will automatically change FlipView.Tag's value and then propagate to all other Images.
在descBox1，hiddenBtn和detailBtn等其他控件中，我们还可以通过更改 ElementName Binding / code>从 photo1 到 narrowFlipview 。以detailBtn为例：
In other controls like "descBox1", "hiddenBtn" and "detailBtn", we can also change their Binding by change ElementName from photo1 to narrowFlipview. Using "detailBtn" for example:
<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=narrowFlipview, Mode=TwoWay, Converter={StaticResource InvertedVisibilityConverter}}">
<Button.Background>
<ImageBrush ImageSource="images/media/ikon-56-app-white-up.png" Stretch="Uniform" />
</Button.Background>
</Button>
编辑后无需更改代码隐藏在XAML中绑定，它应该能够达到你想要的效果。
And there is no need to change the code-behind, after editing the Bindings in XAML, it should be able to achieve what you want.
这篇关于Flipview上的照片和描述的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！