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[英]C++/WinRT WinUI3: How to get html source code by WebView2?
[英]How to get the parent of an object in WinUI3 with C++/WinRT?
这是 xaml 的样子:
<ListView HorizontalContentAlignment="Stretch"
x:Name="listViewMessages"
Grid.Column="1"
ItemsSource="{x:Bind MessageViewModel.Messages}"
Height="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=ActualHeight}"
ItemClick="listViewMessages_ItemClick">
<ListView.HeaderTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
...
</Grid.ColumnDefinitions>
</Grid>
</DataTemplate>
</ListView.HeaderTemplate>
<ListView.ItemTemplate>
<DataTemplate x:DataType="local:Message">
<Grid HorizontalAlignment="{x:Bind Path=MineToHorizontalAlignment()}" Background="{x:Bind Path=MineBackgroundColor()}" CornerRadius="8" Margin="0,6,0,2" Padding="6">
<Grid.ColumnDefinitions>
...
</Grid.ColumnDefinitions>
...
<Button Grid.Column="5" Click="Button_Click">D</Button>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
因此,当我单击按钮时,我想获取单击按钮的列表视图项。
我怎样才能做到这一点?
编辑:我将 xaml 示例更改为更具体的示例。
您需要使用VisualTreeHelper 类来遍历可视化树。 这是一个 C++/WinRT 实用程序,用于递归地遍历父母:
template <typename T>
T GetParent(DependencyObject obj)
{
if (!obj)
return nullptr;
auto parent = Microsoft::UI::Xaml::Media::VisualTreeHelper::GetParent(obj);
if (!parent)
return nullptr;
auto parentAs = parent.try_as<T>();
if (parentAs)
return parentAs;
return GetParent<T>(parent);
}
它的价值是 C# 的对应物:
public static T GetParent<T>(DependencyObject obj) => (T)GetParent(obj, typeof(T));
public static object GetParent(DependencyObject obj, Type type)
{
if (obj == null)
return null;
var parent = VisualTreeHelper.GetParent(obj);
if (parent == null)
return null;
if (type.IsAssignableFrom(parent.GetType()))
return parent;
return GetParent(parent, type);
}
所以你会这样称呼它:
void MainWindow::Button_Click(IInspectable const& sender, RoutedEventArgs const&)
{
auto listView = GetParent<Controls::ListView>(sender.try_as<DependencyObject>());
}
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