我无法使用 VS2012 for Windows Phone 让它工作。如果我使用属性 ValidateOnExceptions=true 创建一个文本框并在设置器中抛出异常，则不会捕获异常，而只会在调试窗口中出现：
A first chance exception of type 'System.ArgumentException' occurred in PhoneApp1.DLL
An exception of type 'System.ArgumentException' occurred in PhoneApp1.DLL but was not handled in user code
System.Windows.Data Error: Cannot save value from target back to source. BindingExpression: Path='Thingy' DataItem='PhoneApp1.MyContext' (HashCode=38891250); target element is 'System.Windows.Controls.TextBox' (Name=''); target property is 'Text' (type 'System.String').. System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentException: I said don't type 'foo'!
at PhoneApp1.MyContext.set_Thingy(String value)
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture)
at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, Object[] index)
at System.Windows.CLRPropertyListener.set_Value(Object value)
at System.Windows.PropertyAccessPathStep.set_Value(Object value)
at System.Windows.Data.BindingExpression.UpdateValue().
我做了一个玩具示例来隔离问题 - 这是我的 xaml：
<phone:PhoneApplicationPage
x:Class="PhoneApp1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:my="clr-namespace:PhoneApp1;assembly=PhoneApp1"
mc:Ignorable="d"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"
SupportedOrientations="Portrait" Orientation="Portrait"
shell:SystemTray.IsVisible="True">
<!--LayoutRoot is the root grid where all page content is placed-->
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<!--TitlePanel contains the name of the application and page title-->
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
<TextBlock Text="Do NOT type 'foo' in this box"/>
<TextBox Text="{Binding Thingy, Mode=TwoWay, ValidatesOnExceptions=True}"/>
</StackPanel>
<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
</Grid>
</Grid>
</phone:PhoneApplicationPage>
我的主页：
/* imports snipped..*/
namespace PhoneApp1 {
public class MyContext {
private String _thingy = String.Empty;
public String Thingy {
get {
return _thingy;
}
set {
if (value == "foo") {
throw new ArgumentException("I said don't type 'foo'!");
}
_thingy = value;
}
}
public MyContext() {
}
}
public partial class MainPage : PhoneApplicationPage {
// Constructor
public MainPage() {
InitializeComponent();
this.DataContext = new MyContext();
}
}
}
我已经对此进行了搜索以寻找线索，但是当 ValidateOnExceptions=true 并且支持 WP8 时，这应该提供视觉反馈似乎非常明确：