Wpf 使用依赖项属性参数化ValidationRules时出现问题
因此,我编写了以下DP和ValidationRule:Wpf 使用依赖项属性参数化ValidationRules时出现问题,wpf,dependency-properties,validationrules,Wpf,Dependency Properties,Validationrules,因此,我编写了以下DP和ValidationRule: public class ComparisonValue : DependencyObject { public Object ComparisonObject { get { return (Object)GetValue(ComparisonObjectProp); } set { SetValue(ComparisonObjectProp, value);
public class ComparisonValue : DependencyObject
{
public Object ComparisonObject
{
get { return (Object)GetValue(ComparisonObjectProp); }
set {
SetValue(ComparisonObjectProp, value);
}
}
public static readonly DependencyProperty ComparisonObjectProp =
DependencyProperty.Register("ComparisonObject", typeof(object), typeof(ComparisonValue), new UIPropertyMetadata(null));
}
public class ObjectComparisonValidator : ValidationRule
{
private ComparisonValue _ObjectToCompare;
public ComparisonValue ObjectToCompare
{
get
{
return _ObjectToCompare;
}
set
{
_ObjectToCompare = value;
}
}
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
if (value != null)
{
if (!value.Equals(ObjectToCompare.ComparisonObject))
{
return new ValidationResult(false, "Values are not equal");
}
else
{
return new ValidationResult(true, null);
}
}
else
{
if (value != ObjectToCompare.ComparisonObject)
{
return new ValidationResult(false, "Values are not equal");
}
else
{
return new ValidationResult(true, null);
}
}
}
}
然后在我的XAML中有以下标记:
<UserControl.Resources>
<l:EnumToStringConverter x:Key="CustomEnumConverter"/>
<l:BooleanToBrushConverter x:Key="BooleanToBrushConverter"/>
<l:ObjectComparisonValidator x:Key="ObjectComparisonValidator"/>
<l:ComparisonValue x:Key="ComparisonValue"/>
</UserControl.Resources>
....
<TextBox Grid.Row="2" Grid.Column="1" Grid.ColumnSpan="2" Height="25" Text="{Binding Path=NetworkKey.Value, UpdateSourceTrigger=PropertyChanged}">
<TextBox.Background>
<Binding Path="NetworkKey.Changed" Converter="{StaticResource BooleanToBrushConverter}">
<Binding.ConverterParameter>
<x:Array Type="Brush">
<SolidColorBrush Color="Yellow"/>
<SolidColorBrush Color="White"/>
</x:Array>
</Binding.ConverterParameter>
</Binding>
</TextBox.Background>
</TextBox>
....
<TextBox Grid.Row="3" Grid.Column="1" Grid.ColumnSpan="2" Height="25">
<TextBox.Text>
<Binding Path="DuplicateNetworkKey.Value" UpdateSourceTrigger="PropertyChanged">
<Binding.ValidationRules>
<l:ObjectComparisonValidator>
<l:ObjectComparisonValidator.ObjectToCompare>
<l:ComparisonValue ComparisonObject="{Binding Path=NetworkKey.Value}"/>
</l:ObjectComparisonValidator.ObjectToCompare>
</l:ObjectComparisonValidator>
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
<TextBox.Background>
<Binding Path="DuplicateNetworkKey.Changed" Converter="{StaticResource BooleanToBrushConverter}">
<Binding.ConverterParameter>
<x:Array Type="Brush">
<SolidColorBrush Color="Yellow"/>
<SolidColorBrush Color="White"/>
</x:Array>
</Binding.ConverterParameter>
</Binding>
</TextBox.Background>
</TextBox>
....
....
现在我遇到的问题是,验证规则的Validate方法被调用,但是当NetworkKey的绑定被触发时,对象的ComparisonValue中的Setter永远不会被调用,因此任何时候验证规则运行时,ObjectComparisonValidator.ObjectToCompare的ComparisonObject属性都为null,因此验证失败。我给ComparisonObject的装订有什么问题
只需要澄清一下,NetworkKey和DuplicateKey(VM中的道具)的类型是INPC类。下面是他们的代码:
public class ValueField<T> : AChangeReportingViewModel, INotifyPropertyChanged
{
private T _OriginalVal;
public T OriginalVal
{
get
{
return _OriginalVal;
}
set
{
_OriginalVal = value;
Value = value;
Changed = false;
PropertyChanged(this, new PropertyChangedEventArgs("OriginalVal"));
}
}
private T _Value;
public T Value
{
get
{
return _Value;
}
set
{
_Value = value;
if (_Value == null)
{
if (_OriginalVal != null) Changed = true;
}
else
{
Changed = !_Value.Equals(_OriginalVal);
}
PropertyChanged(this, new PropertyChangedEventArgs("Value"));
}
}
private Boolean _Changed;
public Boolean Changed
{
get
{
return _Changed;
}
set
{
if (_Changed != value)
{
if (value) ChangeMade();
else ChangeReversed();
}
_Changed = value;
PropertyChanged(this, new PropertyChangedEventArgs("Changed"));
}
}
public event PropertyChangedEventHandler PropertyChanged = delegate { };
}
公共类值字段:AChangeReportingViewModel,INotifyPropertyChanged
{
私人T_OriginalVal;
公共原版
{
得到
{
返回原始值;
}
设置
{
_原始值=值;
价值=价值;
更改=错误;
房地产变更(即新的房地产变更开发项目(“原始”);
}
}
私人T_值;
公共价值
{
得到
{
返回_值;
}
设置
{
_价值=价值;
如果(_值==null)
{
如果(_OriginalVal!=null)更改为true;
}
其他的
{
更改=!\u值。等于(\u原始值);
}
PropertyChanged(即新PropertyChangedEventArgs(“价值”);
}
}
私有布尔值改变;
公共布尔值已更改
{
得到
{
返回-更改;
}
设置
{
如果(_Changed!=值)
{
如果(值)已更改();
else变反了();
}
_改变=价值;
PropertyChanged(即新PropertyChangedEventArgs(“已更改”);
}
}
公共事件PropertyChangedEventHandler PropertyChanged=委托{};
}
它类似于
ElementName
绑定,但不能在可视化树之外进行绑定。请注意,本例中的“Root”是Root UI元素的名称。这是一个非常简单的解决方法。。。比我发现的其他解决方案更好,比如创建绑定代理资源等等。谢谢
<Binding Path="DuplicateNetworkKey.Value" UpdateSourceTrigger="PropertyChanged">
<Binding.ValidationRules>
<l:ObjectComparisonValidator>
<l:ObjectComparisonValidator.ObjectToCompare>
<l:ComparisonValue ComparisonObject="{Binding Path=NetworkKey.Value}"/>
</l:ObjectComparisonValidator.ObjectToCompare>
</l:ObjectComparisonValidator>
</Binding.ValidationRules>
</Binding>
<l:ComparisonValue ComparisonObject="{Binding Source={x:Reference Root}
Path=DataContext.NetworkKey.Value}"/>