FrameworkElement.BindingGroup FrameworkElement.BindingGroup FrameworkElement.BindingGroup FrameworkElement.BindingGroup Property

定义

获取或设置用于该元素的 BindingGroupGets or sets the BindingGroup that is used for the element.

public:
 property System::Windows::Data::BindingGroup ^ BindingGroup { System::Windows::Data::BindingGroup ^ get(); void set(System::Windows::Data::BindingGroup ^ value); };
[System.Windows.Localizability(System.Windows.LocalizationCategory.NeverLocalize)]
public System.Windows.Data.BindingGroup BindingGroup { get; set; }
member this.BindingGroup : System.Windows.Data.BindingGroup with get, set
Public Property BindingGroup As BindingGroup

属性值

用于该元素的 BindingGroupThe BindingGroup that is used for the element.

示例

以下示例是应用程序的一部分, 用于检查用户是否已将两个对象的属性设置为相等值。The following examples are part of an application that checks whether the user has set the properties of two objects to equal values. 第一个示例创建两TextBox个控件, 其中每个控件都绑定到不同的数据源。The first example creates two TextBox controls, each of which is bound to a different data source. 具有一个BindingGroup , 它包含ValidationRule用于检查两个字符串是否相等的。 StackPanelThe StackPanel has a BindingGroup that contains a ValidationRule that checks that the two strings are equal.

<StackPanel>
  <StackPanel.Resources>
    <src:Type1 x:Key="object1" />
    <src:Type2 x:Key="object2" />
  </StackPanel.Resources>

  <StackPanel Name="sp1"
              Margin="5"
              DataContext="{Binding Source={StaticResource object1}}"
              Validation.ValidationAdornerSite="{Binding ElementName=label1}"
              Orientation="Horizontal"
              HorizontalAlignment="Center">

    <StackPanel.BindingGroup>
      <BindingGroup Name="bindingGroup">
        <BindingGroup.ValidationRules>
          <src:BindingGroupValidationRule ValidatesOnTargetUpdated="True" />
        </BindingGroup.ValidationRules>
      </BindingGroup>
    </StackPanel.BindingGroup>

    <TextBlock Text="First string" />

    <TextBox Width="150"
             Text="{Binding Path=PropertyA}" />

    <TextBlock Text="Second string" />

    <TextBox Width="150"
             Text="{Binding Source={StaticResource object2}, 
      Path=PropertyB, BindingGroupName=bindingGroup, 
      TargetNullValue=please enter a string}" />

  </StackPanel>

  <Label Name="label1"
         Content="{Binding ElementName=sp1, Path=(Validation.Errors)[0].ErrorContent}"
         Margin="5"
         Foreground="Red"
         HorizontalAlignment="Center" />

  <Button HorizontalAlignment="Center"
          Click="Button_Click"
          IsDefault="True">
    _Submit
  </Button>

  <StackPanel Orientation="Horizontal">
    <TextBlock Text="First string:"
               FontWeight="Bold" />
    <TextBlock Text="{Binding Source={StaticResource object1}, 
      Path=PropertyA, TargetNullValue=--}" />
  </StackPanel>

  <StackPanel Orientation="Horizontal">
    <TextBlock Text="Second string:"
               FontWeight="Bold" />
    <TextBlock Text="{Binding Source={StaticResource object2}, 
      Path=PropertyB, TargetNullValue=--}" />
  </StackPanel>
</StackPanel>

下面的示例演示ValidationRule前面的示例使用的。The following example shows the ValidationRule that the previous example uses. 在方法重写中, 该示例BindingGroup从获取每个源对象, 并检查对象的属性是否相等。 ValidateIn the Validate method override, the example gets each source object from the BindingGroup and checks whether the properties of the objects are equal.

public class Type1
{
    public string PropertyA { get; set; }

    public Type1()
    {
        PropertyA = "Default Value";
    }
}

public class Type2
{
    public string PropertyB { get; set; }

    public Type2()
    {
    }
}

public class BindingGroupValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
    {
        BindingGroup bg = value as BindingGroup;

        Type1 object1 = null;
        Type2 object2 = null;

        foreach (object item in bg.Items)
        {
            if (item is Type1)
            {
                object1 = item as Type1;
            }

            if (item is Type2)
            {
                object2 = item as Type2;
            }
        }

        if (object1 == null || object2 == null)
        {
            return new ValidationResult(false, "BindingGroup did not find source object.");
        }

        string string1 = bg.GetValue(object1, "PropertyA") as string;
        string string2 = bg.GetValue(object2, "PropertyB") as string;

        if (string1 != string2)
        {
            return new ValidationResult(false, "The two strings must be identical.");
        }

        return ValidationResult.ValidResult;

    }

}
Public Class Type1
    Public Property PropertyA() As String

    Public Sub New()
        PropertyA = "Default Value"
    End Sub
End Class

Public Class Type2
    Public Property PropertyB() As String

    Public Sub New()
    End Sub
End Class

Public Class BindingGroupValidationRule
    Inherits ValidationRule
    Public Overrides Function Validate(ByVal value As Object, ByVal cultureInfo As System.Globalization.CultureInfo) As ValidationResult
        Dim bg As BindingGroup = TryCast(value, BindingGroup)

        Dim object1 As Type1 = Nothing
        Dim object2 As Type2 = Nothing

        For Each item As Object In bg.Items
            If TypeOf item Is Type1 Then
                object1 = TryCast(item, Type1)
            End If

            If TypeOf item Is Type2 Then
                object2 = TryCast(item, Type2)
            End If
        Next item

        If object1 Is Nothing OrElse object2 Is Nothing Then
            Return New ValidationResult(False, "BindingGroup did not find source object.")
        End If

        Dim string1 As String = TryCast(bg.GetValue(object1, "PropertyA"), String)
        Dim string2 As String = TryCast(bg.GetValue(object2, "PropertyB"), String)

        If string1 <> string2 Then
            Return New ValidationResult(False, "The two strings must be identical.")
        End If

        Return ValidationResult.ValidResult

    End Function

End Class

若要调用ValidationRule, 请UpdateSources调用方法。To invoke the ValidationRule, call the UpdateSources method. 下面的示例在UpdateSources按钮的 click 事件发生时调用。The following example calls UpdateSources when the click event of the button occurs.

private void Button_Click(object sender, RoutedEventArgs e)
{
    sp1.BindingGroup.UpdateSources();
}
Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    sp1.BindingGroup.UpdateSources()
End Sub

注解

BindingGroup可用于验证对象的多个属性的值。A BindingGroup can be used to validate the values of multiple properties of an object. 例如, 假设应用程序提示用户输入地址, 然后Address使用属性StreetCityZipCodeCountry值填充类型为的对象, 其中的值为用户规定.For example, suppose that an application prompts the user to enter an address and then populates an object of type Address, which has the properties Street, City, ZipCode, and Country, with the values that the user provided. 应用程序有一个面板, 其中包含TextBox四个控件, 其中每个控件都绑定到对象的一个属性。The application has a panel that contains four TextBox controls, each of which is bound to one of the object's properties. 可以ValidationRule Address在中使用来验证对象。BindingGroupYou can use a ValidationRule in a BindingGroup to validate the Address object. 例如, ValidationRule可以确保邮政编码对地址的国家/地区有效。For example, the ValidationRule can ensure that the zip code is valid for the country/region of the address.

子元素继承其BindingGroup父元素, 就像任何其他可继承的属性一样。Child elements inherit the BindingGroup from their parent elements, just as with any other inheritable property.

依赖项属性信息Dependency Property Information

标识符字段Identifier field BindingGroupProperty
元数据属性设置为trueMetadata properties set to true Inherits

适用于