我在WP 7上有一个奇怪的绑定问题。代码在WP8上运行没有问题,但是当我在WP7上运行相同的(以下)代码时,绑定不起作用,而TextBlock.Text是“”。这是代码(绑定在第二个TextBlock的Text属性上设置):
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,35">
<ListBox x:Name="MainListBox" Margin="0,0,-12,0" SelectionChanged="MainListBox_SelectionChanged">
<StackPanel x:Name="MeasurementUnitPropertyPanel" toolkit:TiltEffect.IsTiltEnabled="True" Margin="12,0,0,0" Orientation="Horizontal" MinHeight="100">
<TextBlock x:Name="MeasurementUnitPropertyLabel" Width="235" Margin="0,30,0,0" HorizontalAlignment="Left" Text="{Binding Path=AppResources.MeasurementUnitPropertyLabel, Source={StaticResource LocalizedStrings}}" Style="{StaticResource PhoneTextLargeStyle}" FontSize="28">
<TextBlock.Foreground>
<SolidColorBrush Color="Black"/>
</TextBlock.Foreground>
</TextBlock>
<TextBlock x:Name="MeasurementUnitPropertyValue" Width="185" Margin="0,30,0,0" TextAlignment="Right" Text="{Binding MeasurementUnit}" Style="{StaticResource PhoneTextLargeStyle}" FontSize="28">
<TextBlock.Foreground>
<SolidColorBrush Color="{StaticResource DarkGrayThemeColor}"/>
</TextBlock.Foreground>
</TextBlock>
</StackPanel>
...
然后我在OnNavigatedTo方法中设置DataContext(或在构造函数中,问题是相同的)...
// When page is navigated to set data context to selected item in list
protected override void OnNavigatedTo(NavigationEventArgs e)
{
viewModel = new ClimateSettingsViewModel();
DataContext = viewModel;
//MeasurementUnitPropertyValue.DataContext = viewModel.MeasurementUnit; //This does not work too...
//Other stuff...
}
(部分)ClimateSettingsViewModel类:
class ClimateSettingsViewModel : INotifyPropertyChanged
{
/// <summary>
/// Sample ViewModel property; this property is used in the view to display its value using a Binding.
/// </summary>
/// <returns></returns>
public String MeasurementUnit
{
get
{
return ClimateSettings.MeasurementUnitValues[App.UserData.SelectedConfiguration.ClimateSettings.MeasurementUnit];
}
/*
set
{
if (value != ClimateSettings.MeasurementUnitValues[App.UserData.SelectedConfiguration.ClimateSettings.MeasurementUnit])
{
App.UserData.SelectedConfiguration.ClimateSettings.MeasurementUnit = value;
NotifyPropertyChanged("MeasurementUnit");
}
}*/
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (null != handler)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
App平台是WP OS 7.1。提前谢谢!
答案 0 :(得分:0)
经过进一步调查后,Windows Phone 7和Windows Phone 8实现了不同的反射。
在Windows Phone 7上,如果您尝试访问私人或内部功能,您将获得MethodAccessException
,但在Windows Phone 8上它将正常工作。
调试时只需打开所有异常,此错误就会跳起来。