AutomationElement.FindFirst(TreeScope, Condition) 方法

  • 參考

定義

命名空間:
System.Windows.Automation
組件:
UIAutomationClient.dll

傳回符合指定條件的第一個子項目或子系元素。

public:
 System::Windows::Automation::AutomationElement ^ FindFirst(System::Windows::Automation::TreeScope scope, System::Windows::Automation::Condition ^ condition);
public System.Windows.Automation.AutomationElement FindFirst (System.Windows.Automation.TreeScope scope, System.Windows.Automation.Condition condition);
member this.FindFirst : System.Windows.Automation.TreeScope * System.Windows.Automation.Condition -> System.Windows.Automation.AutomationElement
Public Function FindFirst (scope As TreeScope, condition As Condition) As AutomationElement

參數

scope
TreeScope

指定搜尋範圍之值的位元組合。

condition
Condition

包含符合準則的物件。

傳回

AutomationElement

符合條件的第一個元素，沒有符合的元素時則為 null。

範例

下列範例示範如何從其識別碼尋找子視窗。

/// <summary>
/// Find a UI Automation child element by ID.
/// </summary>
/// <param name="controlName">Name of the control, such as "button1"</param>
/// <param name="parentElement">Parent element, such as an application window, or the 
/// AutomationElement.RootElement when searching for the application window.</param>
/// <returns>The UI Automation element.</returns>
private AutomationElement FindChildElement(String controlName, AutomationElement rootElement)
{
    if ((controlName == "") || (rootElement == null))
    {
        throw new ArgumentException("Argument cannot be null or empty.");
    }
    // Set a property condition that will be used to find the main form of the
    // target application. In the case of a WinForms control, the name of the control
    // is also the AutomationId of the element representing the control.
    Condition propCondition = new PropertyCondition(
        AutomationElement.AutomationIdProperty, controlName, PropertyConditionFlags.IgnoreCase);

    // Find the element.
    return rootElement.FindFirst(TreeScope.Element | TreeScope.Children, propCondition);
}

''' <summary>
''' Find a UI Automation child element by ID.
''' </summary>
''' <param name="controlName">Name of the control, such as "button1"</param>
''' <param name="rootElement">Parent element, such as an application window, or the 
''' AutomationElement.RootElement when searching for the application window.</param>
''' <returns>The UI Automation element.</returns>
Private Function FindChildElement(ByVal controlName As String, ByVal rootElement As AutomationElement) _
    As AutomationElement
    If controlName = "" OrElse rootElement Is Nothing Then
        Throw New ArgumentException("Argument cannot be null or empty.")
    End If
    ' Set a property condition that will be used to find the main form of the
    ' target application. In the case of a WinForms control, the name of the control
    ' is also the AutomationId of the element representing the control.
    Dim propCondition As New PropertyCondition(AutomationElement.AutomationIdProperty, _
        controlName, PropertyConditionFlags.IgnoreCase)

    ' Find the element.
    Return rootElement.FindFirst(TreeScope.Element Or TreeScope.Children, propCondition)

End Function 'FindChildElement

備註

搜尋的範圍相對於呼叫 方法的專案。

在桌面上搜尋最上層視窗時，請務必在 中 scope 指定 Children ，而不是 Descendants 。 透過桌面整個子樹的搜尋可能會逐一查看數千個專案，並導致堆疊溢位。

如果您的用戶端應用程式可能嘗試在自己的使用者介面中尋找元素，您必須在個別執行緒上進行所有消費者介面自動化呼叫。

適用於

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