Visual.GetVisualChild(Int32) Method

Definition

返回父级 Visual 中的指定 VisualCollectionReturns the specified Visual in the parent VisualCollection.

protected:
 virtual System::Windows::Media::Visual ^ GetVisualChild(int index);
protected virtual System.Windows.Media.Visual GetVisualChild (int index);
abstract member GetVisualChild : int -> System.Windows.Media.Visual
override this.GetVisualChild : int -> System.Windows.Media.Visual
Protected Overridable Function GetVisualChild (index As Integer) As Visual

Parameters

index
Int32

VisualCollection 中的可视对象的索引。The index of the visual object in the VisualCollection.

Returns

Visual

VisualCollection 中指定 index 值处的子级。The child in the VisualCollection at the specified index value.

Examples

下面的示例定义 GetVisualChild的重写实现。The following example defines an overridden implementation of GetVisualChild.

// Provide a required override for the GetVisualChild method.
protected override Visual GetVisualChild(int index)
{
    if (index < 0 || index >= _children.Count)
    {
        throw new ArgumentOutOfRangeException();
    }

    return _children[index];
}
' Provide a required override for the GetVisualChild method.
Protected Overrides Function GetVisualChild(ByVal index As Integer) As Visual
    If index < 0 OrElse index >= _children.Count Then
        Throw New ArgumentOutOfRangeException()
    End If

    Return _children(index)
End Function

Remarks

默认情况下,Visual 没有子级。By default, a Visual has no children. 因此,默认实现始终引发 ArgumentOutOfRangeExceptionTherefore, the default implementation always throws an ArgumentOutOfRangeException.

Notes to Inheritors

派生自 Visual 的类必须重写此方法和 VisualChildrenCount 属性才能正确枚举可视化树。A class that derives from Visual must override this method, and also the VisualChildrenCount property, for the visual tree to be enumerated correctly.

Applies to