AutomationElement.FindFirst(TreeScope, Condition) 方法
定義
重要
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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.AutomationElementPublic 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
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。