获取 UI 自动化元素的属性

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备注

本文档适用于想要使用 System.Windows.Automation 命名空间中定义的托管 UI 自动化类的 .NET Framework 开发人员。 有关 UI 自动化的最新信息，请参阅 Windows 自动化 API：UI 自动化。

本主题演示如何检索 UI 自动化元素的属性。

获取当前属性值

  1. 获取要得到其属性的 AutomationElement。

  2. 调用 GetCurrentPropertyValue 或检索 Current 属性结构，并从其成员之一获取值。

获取缓存的属性值

  1. 获取要得到其属性的 AutomationElement。 必须已在 CacheRequest 中指定了属性。

  2. 调用 GetCachedPropertyValue 或检索 Cached 属性结构，并从其成员之一获取值。

示例

以下示例演示了用于检索 AutomationElement 的当前属性的各种方法。

void PropertyCallsExample(AutomationElement elementList)
{
    // The following two calls are equivalent.
    string name = elementList.Current.Name;
    name = elementList.GetCurrentPropertyValue(AutomationElement.NameProperty) as string;

    // The following shows how to ignore the default property, which
    //  would probably be an empty string if the property is not supported.
    //  Passing "false" as the second parameter is equivalent to using the overload
    //  that does not have this parameter.
    object help = elementList.GetCurrentPropertyValue(AutomationElement.HelpTextProperty, true);
    if (help == AutomationElement.NotSupported)
    {
        help = "No help available";
    }
    string helpText = (string)help;
}

Sub PropertyCallsExample(ByVal elementList As AutomationElement)
    ' The following two calls are equivalent.
    Dim name As String = elementList.Current.Name
    name = CStr(elementList.GetCurrentPropertyValue(AutomationElement.NameProperty))

    ' The following shows how to ignore the default property, which 
    '  would probably be an empty string if the property is not supported.
    '  Passing "false" as the second parameter is equivalent to using the overload
    '  that does not have this parameter.
    Dim help As Object = elementList.GetCurrentPropertyValue(AutomationElement.HelpTextProperty, True)
    If help Is AutomationElement.NotSupported Then
        help = "No help available"
    End If
    Dim helpText As String = CStr(help)

End Sub

请参阅