当 DataTemplate 为 Button 时,ListBox 项返回字符串 [英] ListBox items return string, when DataTemplate is Button
问题描述
我正在创建一个 WP 8.1 Silverlight 应用程序.
I am creating a WP 8.1 Silverlight app.
我有一个字符串名称的 ObservableCollection
,它被设置为 ListBox
的 ItemsSource
.ListBox
中的按钮名称.然后我想从 ListBox
中提取按钮,但返回值是 string
类型.
I have an ObservableCollection
of string names, that is set to the ItemsSource
of a ListBox
. Which are the names of buttons in the ListBox
. I then want to extract the buttons from the ListBox
, but the return value is of type string
.
xaml 代码为:
<ListBox x:Name="Game_ScrollViewer_online" Margin="41,104,128,6" SelectedValuePath="Current_game_button">
<ListBox.ItemTemplate>
<DataTemplate>
<Button x:Name="Current_game_button" Content="{Binding}"
HorizontalAlignment="Center" Height="80" Margin="-14,6,-15,0"
VerticalAlignment="Top" Width="210" Template="{StaticResource Button_CurrentLayout1}"
RenderTransformOrigin="0.5,0.5" Foreground="#FFCBECCB" FontFamily="Times New Roman"
Click="LoadGame_online" FontSize="16">
</Button>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
然后我想提取按钮元素:
I then want to extract the button element:
for (int i = 0; i < Game_ScrollViewer_online.Items.Count; i++)
{
var tempType = Game_ScrollViewer_online.Items[i].GetType();
Button tempBut = (Game_ScrollViewer_online.Items[i] as Button);
//Do stuff with button
}
但如前所述,返回类型是字符串.
But as said the return type is string.
为什么不是按钮?有没有办法访问按钮?
Why is it not button ? And is there a way to access the button?
推荐答案
您需要 FrameworkTemplate.FindName Method (String, FrameworkElement)
用于此目的:
You need FrameworkTemplate.FindName Method (String, FrameworkElement)
for this purpose:
private childItem FindVisualChild<childItem>(DependencyObject obj)
where childItem : DependencyObject
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
{
DependencyObject child = VisualTreeHelper.GetChild(obj, i);
if (child != null && child is childItem)
return (childItem)child;
else
{
childItem childOfChild = FindVisualChild<childItem>(child);
if (childOfChild != null)
return childOfChild;
}
}
return null;
}
那么:
for (int i = 0; i < Game_ScrollViewer_online.Items.Count; i++)
{
ListBoxItem GameListBoxItem = (ListBoxItem)(Game_ScrollViewer_online.ItemContainerGenerator.ContainerFromIndex(i));
ContentPresenter contentPresenter = FindVisualChild<ContentPresenter>(GameListBoxItem);
DataTemplate myDataTemplate = contentPresenter.ContentTemplate;
Button tempBut = (Button) myDataTemplate.FindName("Current_game_button", contentPresenter);
//Do stuff with button
}
要解决丢失的 FindName
使用 FindDescendant
像这样:
To solve missing FindName
use FindDescendant
like this:
public T FindDescendant<T>(DependencyObject obj) where T : DependencyObject
{
if (obj is T)
return obj as T;
int childrenCount = VisualTreeHelper.GetChildrenCount(obj);
if (childrenCount < 1)
return null;
for (int i = 0; i < childrenCount; i++)
{
DependencyObject child = VisualTreeHelper.GetChild(obj, i);
if (child is T)
return child as T;
}
for (int i = 0; i < childrenCount; i++)
{
DependencyObject child = FindDescendant<T>(VisualTreeHelper.GetChild(obj, i));
if (child != null && child is T)
return child as T;
}
return null;
}
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