好幾個小時的谷歌搜索和stakoverflow閱讀,我一直無法找到這個問題的答案。 我有一個UserControl
用於顯示一個ProgressBar
與DependencyProperty
類型double
。UserControl中的DependencyProperty不能綁定在ListItem模板中
MainPage.xaml.cs中包含DataContext
:
void MainPage_Loaded(object sender,RoutedEventArgs e)
{
setDataContext();
MainGameListBox.ItemsSource = vm.GameList;
}
這是什麼在MainPage.xaml:
<ListBox Grid.Row="1" Grid.ColumnSpan="2" x:Name="MainGameListBox"
SelectionChanged="listBoxGameSearch_SelectionChanged" >
<!-- set its ItemsPanel to be a WrapPanel -->
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<toolkit1:WrapPanel />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<toolkit1:ContextMenuService.ContextMenu>
<toolkit1:ContextMenu>
<toolkit1:MenuItem Header="Pin to start" Click="PinGameToStart_Click" />
</toolkit1:ContextMenu>
</toolkit1:ContextMenuService.ContextMenu>
<Grid Width="173" Height="173"
Background="{StaticResource PhoneAccentBrush}" Margin="12">
<Grid.RowDefinitions>
<RowDefinition Height="32"/>
<RowDefinition Height="32"/>
<RowDefinition Height="32"/>
<RowDefinition Height="32"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="86.5"/>
<ColumnDefinition Width="86.5"/>
</Grid.ColumnDefinitions>
<Border Grid.Row="0" Grid.RowSpan="3" Grid.Column="0" Width="64"
Height="64" BorderBrush="#70BC1F" BorderThickness="2"
Margin="6,6,0,0" VerticalAlignment="Top"
HorizontalAlignment="Left">
<Image Source="{Binding GameTile,
Converter={StaticResource imageCacheConverter}}" />
</Border>
<view:CircularProgressChart x:Name="circularProgChart"
Grid.Row="0" Grid.Column="1"
Grid.RowSpan="3" Grid.ColumnSpan="2"
Margin="6"
Loaded="CircularProgressChart_Loaded"
CompletionPercent="{Binding CompletionPercentage}" />
</Grid>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
的CompletionPercent
是DP和UserControl
低於:
public partial class CircularProgressChart:UserControl
{
public double CompletionPercent
{
get { return (double)GetValue(CompletionPercentProperty); }
set { SetValue(CompletionPercentProperty, value); }
}
public static readonly DependencyProperty CompletionPercentProperty = DependencyProperty.Register("CompletionPercent", typeof(double), typeof(CircularProgressChart), new PropertyMetadata(0.0, CompletionPercentChanged));
public CircularProgressChart()
{
try
{
InitializeComponent();
DataContext = this;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
這是CompletionPercentage
地產:
public class Progress : INotifyPropertyChanged
{
private double _completionPercentage = 0.0;
public double CompletionPercentage
{
get{return _completionPercentage;}
set{
_completionPercentage = value;
NotifyPropertyChanged("CompletionPercentage");
}
}
protected void NotifyPropertyChanged(string name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(name));
}
}
}
問題,就是爲什麼在 CompletionPercent="{Binding CompletionPercentage}"
不被約束?它獲得默認值0,但是當更新CompletionPercentage
時,DP不會獲得更新。我檢查了NotifyPropertyChanged
方法,它正確觸發並在代碼的所有其他部分工作。