TextPattern.MarginLeadingAttribute 字段    
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
标识文本范围的 MarginLeading (PageSettings) 特性。
public: static initonly System::Windows::Automation::AutomationTextAttribute ^ MarginLeadingAttribute;public static readonly System.Windows.Automation.AutomationTextAttribute MarginLeadingAttribute; staticval mutable MarginLeadingAttribute : System.Windows.Automation.AutomationTextAttributePublic Shared ReadOnly MarginLeadingAttribute As AutomationTextAttribute 字段值
示例
以下示例演示如何在记事本Microsoft获取一系列文本的属性值。
注意
Microsoft记事本用作文本提供程序,仅用于例如目的。 Microsoft记事本不保证支持所请求的属性值。
private void GetMarginLeadingAttribute()
{
    // Start application.
    Process p = Process.Start("Notepad.exe", "text.txt");
    // target --> The root AutomationElement.
    AutomationElement target = AutomationElement.FromHandle(p.MainWindowHandle);
    // Specify the control type we're looking for, in this case 'Document'
    PropertyCondition cond = new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Document);
    AutomationElement textProvider = target.FindFirst(TreeScope.Descendants, cond);
    TextPattern textpatternPattern = textProvider.GetCurrentPattern(TextPattern.Pattern) as TextPattern;
    if (textpatternPattern == null)
    {
        Console.WriteLine("Root element does not contain a descendant that supports TextPattern.");
        return;
    }
    Object oAttribute = textpatternPattern.DocumentRange.GetAttributeValue(TextPattern.MarginLeadingAttribute);
    if (oAttribute == TextPattern.MixedAttributeValue)
    {
        Console.WriteLine("Mixed leading margins.");
    }
    else
    {
        Console.WriteLine(oAttribute.ToString());
    }
}
Private Sub GetMarginLeadingAttribute()
    ' Start application.
    Dim p As Process = Process.Start("Notepad.exe", "text.txt")
    ' target --> The root AutomationElement.
    Dim target As AutomationElement = AutomationElement.FromHandle(p.MainWindowHandle)
    ' Specify the control type we're looking for, in this case 'Document'
    Dim cond As PropertyCondition = New PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Document)
    Dim textProvider As AutomationElement = target.FindFirst(TreeScope.Descendants, cond)
    Dim textpatternPattern As TextPattern = CType(textProvider.GetCurrentPattern(TextPattern.Pattern), TextPattern)
    If (textpatternPattern Is Nothing) Then
        Console.WriteLine("Root element does not contain a descendant that supports TextPattern.")
        Return
    End If
    Dim oAttribute As Object = textpatternPattern.DocumentRange.GetAttributeValue(TextPattern.MarginLeadingAttribute)
    If (oAttribute = TextPattern.MixedAttributeValue) Then
        Console.WriteLine("Mixed leading margins.")
    Else
        Console.WriteLine(oAttribute.ToString())
    End If
End Sub
注解
此属性表示应用于页面的前导边距, (与调用文本范围关联的) 。
此标识符由UI 自动化客户端应用程序使用。 UI 自动化提供程序应使用 中的TextPatternIdentifiers等效字段。
UI 自动化客户端通过调用 GetAttributeValue获取 属性的值。
此属性的值的类型为 Double。 默认值是 zero。