BindingGroup.Items Property

Definition

BindingGroup의 바인딩 개체에 사용되는 소스를 가져옵니다.Gets the sources that are used by the Binding objects in the BindingGroup.

public:
 property System::Collections::IList ^ Items { System::Collections::IList ^ get(); };
public System.Collections.IList Items { get; }
member this.Items : System.Collections.IList
Public ReadOnly Property Items As IList

Property Value

IList

BindingGroup의 바인딩 개체에 사용되는 소스입니다.The sources that are used by the Binding objects in the BindingGroup.

Examples

다음 예제는 사용자가 값과 동일 하 게 두 개체의 속성을 설정 하는지 여부를 확인 하는 애플리케이션의 일부입니다.The following examples are part of an application that checks whether the user has set the properties of two objects to equal values. 첫 번째 예제에서는 두 개의 TextBox 각각은 서로 다른 소스에 바인딩된 데이터 컨트롤입니다.The first example creates two TextBox controls, each of which are data bound to a different source. 첫 번째의 바인딩을 TextBox 해당 소스를 가져옵니다 object1에서 DataContextTextBox 컨트롤의 부모 요소 (의 StackPanel).The binding of the first TextBox gets its source, object1, from the DataContext of the TextBox control's parent element (the StackPanel). 두 번째 TextBox, 바인딩 소스를로 object2합니다.On the second TextBox, the source of the binding is set to object2. 예제에서는 Label 유효성 검사 오류를 표시 하는 합니다.The example also creates a Label that displays validation errors.

<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" />

다음 예제는 ValidationRule 앞의 예제를 사용 하는 합니다.The following example shows the ValidationRule that the previous example uses. Validate 메서드를 예제에서 각 원본 개체를 가져옵니다는 BindingGroup 개체 속성이 같은지 여부를 확인 합니다.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

Remarks

원본에 추가 됨에 따라 사용 되는 각 개체는 Items 속성을 한 번에 여러 바인딩에 대 한 개체를 원본으로 사용 되는 경우에 합니다.Each object that is used as a source is added into the Items property once, even if the object is used as the source for multiple bindings. 종종 항목이 하나만에서 Items는 개체인를 DataContext 를 사용 하는 요소는 BindingGroup.Often, there is just one item in Items, which is the object that is the DataContext of the element that uses the BindingGroup. 하지만 이기는 BindingGroup 여러 원본에 있어야 합니다.It is possible for a BindingGroup to have multiple sources, however. 예를 들어 동일한 바인딩 개체 공유 BindingGroupName 다양 한 원본 개체를 사용 하지만 원본으로 사용 되는 각 개체에는 Items합니다.For example, if Binding objects share the same BindingGroupName but use different source objects, each object that is used as a source is in Items.

여러 개체에 있을 수도 있습니다 Items 원본의 중첩 된 속성에 바인딩 경로 확인 하는 경우.There can also be multiple objects in Items if the path of a Binding resolves to a nested property of the source. 예를 들어를 TextBox 컨트롤의 바인딩의 일부인를 BindingGroup 및 해당 DataContextCustomer 형식의 속성이 있는 개체 Address합니다.For example, suppose a TextBox control's binding is a part of a BindingGroup and its DataContext is a Customer object, which has a property of type Address. 경우는 PathBindingAddress.ZipCode 속성인을 Address 에 추가 됩니다는 Items 속성.If the Path of the Binding is the Address.ZipCode property, the Address is added to the Items property.

Applies to