BindingGroup.Name 属性

定义

获取或设置标识 BindingGroup 的名称,该名称可用于在 BindingGroup 中包括和排除绑定对象。Gets or sets the name that identifies the BindingGroup, which can be used to include and exclude Binding objects in the BindingGroup.

public:
 property System::String ^ Name { System::String ^ get(); void set(System::String ^ value); };
public string Name { get; set; }
member this.Name : string with get, set
Public Property Name As String

属性值

String

标识 BindingGroup 的名称。The name that identifies the BindingGroup.

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. 第一个示例创建两个 TextBox 控件,其中每个控件都绑定到不同的源。The first example creates two TextBox controls, each of which are data bound to a different source. 第一个的绑定 TextBox 是的一部分, BindingGroup 因为 TextBox 继承 DataContext BindingGroup 其父对象中的和 StackPanelThe binding of the first TextBox is part of the BindingGroup because the TextBox inherits the DataContext and BindingGroup from its parent StackPanel.

第二个的绑定 TextBox 是的一部分,原因是的和的均 BindingGroup Name BindingGroup BindingGroupName Binding 设置为 bindingGroupThe binding on the second TextBox is part of the BindingGroup because the Name of the BindingGroup and the BindingGroupName of the Binding are both set to bindingGroup.

<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" />

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. Validate 方法中,该示例从获取每个源对象 BindingGroup ,并检查对象的属性是否相等。In the Validate method, 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

注解

如果 Namenull ,则具有与具有参与的元素的相同的源的绑定 DataContext BindingGroup BindingGroupIf Name is null, bindings that have a source that is the same object as the DataContext of the element that has the BindingGroup participate in the BindingGroup.

可以包含与父元素的源不同的绑定,该 DataContext 父元素的 BindingGroup 设置为 Name BindingGroup ,并将 BindingGroupName 绑定的属性设置为相同的值。You can include bindings that have a source that is different from the DataContext of the parent element that has the BindingGroup by setting Name of the BindingGroup and the BindingGroupName property of a binding to the same value. 您可以排除与父元素具有相同源的绑定, DataContext 该父元素的 BindingGroup 设置为 Name BindingGroup ,并将绑定的 BindingGroupName 属性设置为不同的值。You can exclude bindings that have the same source as DataContext of the parent element that has the BindingGroup by setting Name of the BindingGroup and the BindingGroupName property of a binding to different values.

适用于