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[英]UWP GridView/ListView get the RightTapped Item supporting both mouse and Xbox Controller
[英]UWP: how to get the RightTapped GridView Item
我有一個像下面的GridView
<GridView
SelectionMode="None"
IsItemClickEnabled="True"
IsRightTapEnabled="True"
ItemsSource="{x:Bind SymbolItems}"
ItemClick="SymbolGridView_ItemClick"
RightTapped="SymbolGridView_RightTapped">
<GridView.ItemTemplate>
<DataTemplate x:DataType="data:SoundSymbolItem">
<local:SymbolControl/>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
我有一個ItemClick
處理程序,我可以成功獲取被單擊的symbolItem
private void SymbolGridView_ItemClick(object sender, ItemClickEventArgs e)
{
var symbolItem = (SymbolItem)e.ClickedItem;
MyMediaElement.Source = new Uri(this.BaseUri, symbolItem.SymbolAudio);
}
現在,我想為RightTapped
事件做類似的事情,但它無法獲得正確的被點擊項目。
private void SymbolGridView_RightTapped(object sender, RightTappedRoutedEventArgs e)
{
SymbolItem symbolItem = (sender as GridViewItem).DataContext as SymbolItem;
MyMediaElement.Source = new Uri(this.BaseUri, symbolItem.ExampleAudio);
}
我在這個問題上建模答案Get RightTapped GridViewItem以在上面編寫我的右擊處理程序,但是它不起作用。 當我右鍵單擊gridview項時,將觸發NullReferenceException。
如果ItemTemplate中的SymbolControl稍微復雜一點,並且其中的元素可能具有自己的DataContext,則可以使用以下輔助方法獲取對父ListViewItemPresenter的引用,然后將其DataContext強制轉換為Symbol項目:
private void SymbolGridView_RightTapped(object sender, RightTappedRoutedEventArgs e)
{
ListViewItemPresenter lvi = e.OriginalSource as ListViewItemPresenter;
if (lvi == null)
lvi = FindParent<ListViewItemPresenter>(e.OriginalSource as DependencyObject);
if (lvi != null)
{
SymbolItem clickedItem = lvi.DataContext as SymbolItem;
if (clickedItem != null)
MyMediaElement.Source = new Uri(this.BaseUri, symbolItem.ExampleAudio);
}
}
private static T FindParent<T>(DependencyObject dependencyObject) where T : DependencyObject
{
var parent = VisualTreeHelper.GetParent(dependencyObject);
if (parent == null) return null;
var parentT = parent as T;
return parentT ?? FindParent<T>(parent);
}
您應該在gridview中設置SelectionMode="Single"
並設置IsRightTapEnabled="True"
。
我的模特有一個Student
班:
public class Student : NotifyProperty
{
public string Name
{
set
{
_name = value;
OnPropertyChanged();
}
get
{
return _name;
}
}
private string _name;
}
我的視圖模型有一個List<Student>
。
我將列表設置為gridview的源。
我的GridView是
<GridView x:Name="SymbolGridView"
SelectionMode="Single"
IsItemClickEnabled="True"
IsRightTapEnabled="True"
ItemsSource="{x:Bind View.Student}"
ItemClick="SymbolGridView_OnItemClick"
RightTapped="SymbolGridView_OnRightTapped">
<GridView.ItemTemplate>
<DataTemplate x:DataType="view:ViewModel">
<TextBlock Text="{Binding Name}"></TextBlock>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
SymbolGridView_OnRightTapped
的OriginalSource是TextBlock。但是,如果您的DataTemlpate是Grid,則OriginalSource是Grid。
我們可以使用var student = (e.OriginalSource as TextBlock)?.DataContext as Student;
得到學生。
OriginalSource.DataContext是您的選擇項
但是,如果使用網格,則OriginalSource可能是ListViewItemPresenter。因此,簡單的方法是使用var student = (e.OriginalSource as FrameworkElement)?.DataContext as Student;
請參閱: http : //lindexi.oschina.io/lindexi/post/win10-uwp-%E5%8F%B3%E5%87%BB%E9%80%89%E6%8B%A9GridViewItem
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