BindingGroup.Name 屬性

定義

命名空間:

System.Windows.Data

組件:

PresentationFramework.dll

取得或設定名稱，這個名稱會識別用來包含和排除 BindingGroup 中 Binding 物件的 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

屬性值

String

可識別 BindingGroup 的名稱。

範例

下列範例是應用程式一部分，會檢查使用者是否已將兩個物件的屬性設定為相等值。 第一個範例會建立兩 TextBox 個控制項，每個控制項都是系結至不同來源的資料。 第一個 TextBox 的系結是 的 BindingGroup 一部分，因為 TextBox 繼承 DataContext 自其父系 StackPanel 的 和 BindingGroup 。

第二 TextBox 個上的系結是 的一部分 BindingGroup ，因為 Name BindingGroup 和 BindingGroupName 的 Binding 都設定為 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" />

下列範例顯示 ValidationRule 上一個範例所使用的 。 Validate在 方法中，此範例會從 BindingGroup 取得每個來源物件，並檢查 物件的屬性是否相等。

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

備註

如果 Name 為 null ，則系結具有與具有 BindingGroup 參與 BindingGroup 之專案的 物件相同 DataContext 之 來源的系結。

您可以藉由將 系結的 BindingGroup 和 BindingGroupName 系結的 屬性設定 Name 為相同值，來包含與父 BindingGroup 元素不同 DataContext 之 來源的系結。 您可以藉由將 系結的 BindingGroup 和 BindingGroupName 系結的 屬性設定 Name 為不同的值，排除與父 BindingGroup 元素具有相同來源 DataContext 的系結。