我正在写一个 Windows Phone 8.1（WINRT）应用程序。
我的列表框带有 datatemplate 。在datatemplate里面，我有一个网格和一个文本块。 如何从c＃设置网格或文本块的宽度？
我尝试使用来自互联网的DependencyObject VisualTreeHelper方法，但它无效。
XAML：
<SemanticZoom x:Name="CategorySemanticZoom"
IsZoomOutButtonEnabled="True"
CanChangeViews="True"
Grid.Row="1">
<SemanticZoom.ZoomedInView>
<ListView x:Name="Category_ListViewDetail" IsSwipeEnabled="True" IsTapEnabled="True"
IsItemClickEnabled="True"
IsZoomedInView="True"
ItemClick="Category_ListViewDetail_ItemClick" >
<ListView.ItemTemplate>
<DataTemplate>
<Grid x:Name="SubCategoryName_grid"
x:FieldModifier="public"
>
<TextBlock
Text="{Binding SubCategoryName}"
x:Name="SubCategoryName_TextBlock"
FontSize="26"
Margin="30,0,10,0"
TextTrimming="CharacterEllipsis"/>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.HeaderTemplate>
<DataTemplate>
<Border Background="{StaticResource DefaultTheme_DarkBlueColor}"
CornerRadius="6"
HorizontalAlignment="Left"
Margin="10,20,10,20"
Tapped="Border_Tapped"
VerticalAlignment="Center">
<TextBlock Text="{Binding CategoryName}"
/>
</Border>
</DataTemplate>
</GroupStyle.HeaderTemplate>
<GroupStyle.Panel>
<ItemsPanelTemplate>
<VariableSizedWrapGrid Orientation="Vertical"
Margin="0 0 0 0"
ItemHeight="55"/>
</ItemsPanelTemplate>
</GroupStyle.Panel>
</GroupStyle>
</ListView.GroupStyle>
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Vertical" />
</ItemsPanelTemplate>
</ListView.ItemsPanel>
</ListView>
</SemanticZoom.ZoomedInView>
<SemanticZoom.ZoomedOutView>
<ListView x:Name="Category_ListViewSummary"
Background="LightGray"
IsZoomedInView="False"
Opacity=".85">
<ListView.ItemTemplate>
<DataTemplate>
<Border Background="{StaticResource DefaultTheme_DarkBlueColor}"
CornerRadius="6"
HorizontalAlignment="Left"
Margin="10,10,10,10" >
<TextBlock Text="{Binding Group.CategoryName}"
/>
</Border>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</ListView.ItemsPanel>
</ListView>
</SemanticZoom.ZoomedOutView>
</SemanticZoom>
如何从C＃设置 SubCategoryName_grid 或 SubCategoryName_TextBlock 的宽度？
答案 0 :(得分：1)
DependencyObject findElementInItemsControlItemAtIndex(ItemsControl itemsControl,
int itemOfIndexToFind,
string nameOfControlToFind)
{
if (itemOfIndexToFind >= itemsControl.Items.Count) return null;
DependencyObject depObj = null;
object o = itemsControl.Items[itemOfIndexToFind];
if (o != null)
{
var item = itemsControl.ItemContainerGenerator.ContainerFromItem(o);
if (item != null)
{
depObj = getVisualTreeChild(item, nameOfControlToFind);
return depObj;
}
}
return null;
}
DependencyObject getVisualTreeChild(DependencyObject obj, String name)
{
DependencyObject dependencyObject = null;
int childrenCount = VisualTreeHelper.GetChildrenCount(obj);
for (int i = 0; i < childrenCount; i++)
{
var oChild = VisualTreeHelper.GetChild(obj, i);
var childElement = oChild as FrameworkElement;
if (childElement != null)
{
//Code to take care of Paragraph/Run
if (childElement is RichTextBlock || childElement is TextBlock)
{
dependencyObject = childElement.FindName(name) as DependencyObject;
if (dependencyObject != null)
return dependencyObject;
}
if (childElement.Name == name)
{
return childElement;
}
}
dependencyObject = getVisualTreeChild(oChild, name);
if (dependencyObject != null)
return dependencyObject;
}
return dependencyObject;
}
private void Category_ListViewDetail_Loaded(object sender, RoutedEventArgs e)
{
ListView ListViewObject = sender as ListView;
//For changing Detail Sub Categories Width:
int CategoriesCount = ListViewObject.Items.Count;
for (int i = 0; i < CategoriesCount; i++)
{
TextBlock SubCategory_TextBlockObject = findElementInItemsControlItemAtIndex(ListViewObject, i, "SubCategoryName_TextBlock") as TextBlock;
if (SubCategory_TextBlockObject != null)
{
SubCategory_TextBlockObject.Width = Window.Current.Bounds.Width - 50;
}
}
for (int i = 0; i < CategoriesCount; i++)
{
TextBlock Category_TextBlockObject = findElementInItemsControlItemAtIndex(ListViewObject, i, "CategoryName_InDetailView_Textblock") as TextBlock;
if (Category_TextBlockObject != null)
{
Category_TextBlockObject.Width = Window.Current.Bounds.Width - 30;
}
}
}
private void Category_ListViewSummary_Loaded(object sender, RoutedEventArgs e)
{
//For changing Summary Categories Width:
ListView ListViewObject = sender as ListView;
int CategoriesCount = GetCategoriesResultObject.MasterCategories[0].Categories.Count;
for(int i=0;i<CategoriesCount;i++)
{
TextBlock Category_TextBlockObject = findElementInItemsControlItemAtIndex(ListViewObject, i, "CategoryName_Textblock") as TextBlock;
if (Category_TextBlockObject != null)
{
Category_TextBlockObject.Width = Window.Current.Bounds.Width - 30;
}
}
}