CacheRequest 클래스

정의

네임스페이스:

System.Windows.Automation

어셈블리:

UIAutomationClient.dll

AutomationElement 가져올 때 UI 자동화 프레임워크에서 캐시하는 속성과 패턴을 지정합니다.

public ref class CacheRequest sealed

public sealed class CacheRequest

type CacheRequest = class

Public NotInheritable Class CacheRequest

상속

Object

CacheRequest

예제

다음 예제에서는 패턴 및 속성을 캐시하는 데 사용하는 Activate 방법을 보여 줍니다.

/// <summary>
/// Caches and retrieves properties for a list item by using CacheRequest.Activate.
/// </summary>
/// <param name="elementList">Element from which to retrieve a child element.</param>
/// <remarks>
/// This code demonstrates various aspects of caching. It is not intended to be 
/// an example of a useful method.
/// </remarks>
private void CachePropertiesByActivate(AutomationElement elementList)
{
    AutomationElement elementListItem;

    // Set up the request.
    CacheRequest cacheRequest = new CacheRequest();
    cacheRequest.Add(AutomationElement.NameProperty);
    cacheRequest.Add(AutomationElement.IsEnabledProperty);
    cacheRequest.Add(SelectionItemPattern.Pattern);
    cacheRequest.Add(SelectionItemPattern.SelectionContainerProperty);

    // Obtain an element and cache the requested items.
    using (cacheRequest.Activate())
    {
        Condition cond = new PropertyCondition(AutomationElement.IsSelectionItemPatternAvailableProperty, true);
        elementListItem = elementList.FindFirst(TreeScope.Children, cond);
    }
    // The CacheRequest is now inactive.

    // Retrieve the cached property and pattern.
    SelectionItemPattern pattern;
    String itemName;
    try
    {
        itemName = elementListItem.Cached.Name;
        pattern = elementListItem.GetCachedPattern(SelectionItemPattern.Pattern) as SelectionItemPattern;
    }
    catch (InvalidOperationException)
    {
        Console.WriteLine("Object was not in cache.");
        return;
    }
    // Alternatively, you can use TryGetCachedPattern to retrieve the cached pattern.
    object cachedPattern;
    if (true == elementListItem.TryGetCachedPattern(SelectionItemPattern.Pattern, out cachedPattern))
    {
        pattern = cachedPattern as SelectionItemPattern;
    }

    // Specified pattern properties are also in the cache.
    AutomationElement parentList = pattern.Cached.SelectionContainer;

    // The following line will raise an exception, because the HelpText property was not cached.
    /*** String itemHelp = elementListItem.Cached.HelpText; ***/

    // Similarly, pattern properties that were not specified in the CacheRequest cannot be 
    // retrieved from the cache. This would raise an exception.
    /*** bool selected = pattern.Cached.IsSelected; ***/

    // This is still a valid call, even though the property is in the cache.
    // Of course, the cached value and the current value are not guaranteed to be the same.
    itemName = elementListItem.Current.Name;
}

''' <summary>
''' Caches and retrieves properties for a list item by using CacheRequest.Activate.
''' </summary>
''' <param name="elementList">Element from which to retrieve a child element.</param>
''' <remarks>
''' This code demonstrates various aspects of caching. It is not intended to be 
''' an example of a useful method.
''' </remarks>
Private Sub CachePropertiesByActivate(ByVal elementList As AutomationElement)

    ' Set up the request.
    Dim myCacheRequest As New CacheRequest()
    myCacheRequest.Add(AutomationElement.NameProperty)
    myCacheRequest.Add(AutomationElement.IsEnabledProperty)
    myCacheRequest.Add(SelectionItemPattern.Pattern)
    myCacheRequest.Add(SelectionItemPattern.SelectionContainerProperty)

    Dim elementListItem As AutomationElement

    ' Obtain an element and cache the requested items.
    Using myCacheRequest.Activate()
        Dim myCondition As New PropertyCondition( _
            AutomationElement.IsSelectionItemPatternAvailableProperty, True)
        elementListItem = elementList.FindFirst(TreeScope.Children, myCondition)
    End Using


    ' The CacheRequest is now inactive.
    ' Retrieve the cached property and pattern.
    Dim pattern As SelectionItemPattern
    Dim itemName As String
    Try
        itemName = elementListItem.Cached.Name
        pattern = DirectCast(elementListItem.GetCachedPattern(SelectionItemPattern.Pattern), _
            SelectionItemPattern)
    Catch ex As InvalidOperationException
        Console.WriteLine("Object was not in cache.")
        Return
    End Try
    ' Alternatively, you can use TryGetCachedPattern to retrieve the cached pattern.
    Dim cachedPattern As Object = Nothing
    If True = elementListItem.TryGetCachedPattern(SelectionItemPattern.Pattern, cachedPattern) Then
        pattern = DirectCast(cachedPattern, SelectionItemPattern)
    End If

    ' Specified pattern properties are also in the cache.
    Dim parentList As AutomationElement = pattern.Cached.SelectionContainer

    ' The following line will raise an exception, because the HelpText property was not cached.
    '** String itemHelp = elementListItem.Cached.HelpText; **

    ' Similarly, pattern properties that were not specified in the CacheRequest cannot be 
    ' retrieved from the cache. This would raise an exception.
    '** bool selected = pattern.Cached.IsSelected; **

    ' This is still a valid call, even though the property is in the cache.
    ' Of course, the cached value and the current value are not guaranteed to be the same.
    itemName = elementListItem.Current.Name
End Sub

다음 예제에서는 패턴 및 Pop 속성을 사용하고 Push 캐시하는 방법을 보여 줍니다.

/// <summary>
/// Caches and retrieves properties for a list item by using CacheRequest.Push.
/// </summary>
/// <param name="autoElement">Element from which to retrieve a child element.</param>
/// <remarks>
/// This code demonstrates various aspects of caching. It is not intended to be 
/// an example of a useful method.
/// </remarks>
private void CachePropertiesByPush(AutomationElement elementList)
{
    // Set up the request.
    CacheRequest cacheRequest = new CacheRequest();

    // Do not get a full reference to the cached objects, only to their cached properties and patterns.
    cacheRequest.AutomationElementMode = AutomationElementMode.None;

    // Cache all elements, regardless of whether they are control or content elements.
    cacheRequest.TreeFilter = Automation.RawViewCondition;

    // Property and pattern to cache.
    cacheRequest.Add(AutomationElement.NameProperty);
    cacheRequest.Add(SelectionItemPattern.Pattern);

    // Activate the request.
    cacheRequest.Push();

    // Obtain an element and cache the requested items.
    Condition cond = new PropertyCondition(AutomationElement.IsSelectionItemPatternAvailableProperty, true);
    AutomationElement elementListItem = elementList.FindFirst(TreeScope.Children, cond);

    // At this point, you could call another method that creates a CacheRequest and calls Push/Pop.
    // While that method was retrieving automation elements, the CacheRequest set in this method 
    // would not be active. 

    // Deactivate the request.
    cacheRequest.Pop();

    // Retrieve the cached property and pattern.
    String itemName = elementListItem.Cached.Name;
    SelectionItemPattern pattern = elementListItem.GetCachedPattern(SelectionItemPattern.Pattern) as SelectionItemPattern;

    // The following is an alternative way of retrieving the Name property.
    itemName = elementListItem.GetCachedPropertyValue(AutomationElement.NameProperty) as String;

    // This is yet another way, which returns AutomationElement.NotSupported if the element does
    // not supply a value. If the second parameter is false, a default name is returned.
    object objName = elementListItem.GetCachedPropertyValue(AutomationElement.NameProperty, true);
    if (objName == AutomationElement.NotSupported)
    {
        itemName = "Unknown";
    }
    else
    {
        itemName = objName as String;
    }

    // The following call raises an exception, because only the cached properties are available, 
    //  as specified by cacheRequest.AutomationElementMode. If AutomationElementMode had its
    //  default value (Full), this call would be valid.
    /*** bool enabled = elementListItem.Current.IsEnabled; ***/
}

''' <summary>
''' Caches and retrieves properties for a list item by using CacheRequest.Push.
''' </summary>
''' <param name="elementList">Element from which to retrieve a child element.</param>
''' <remarks>
''' This code demonstrates various aspects of caching. It is not intended to be 
''' an example of a useful method.
''' </remarks>
Private Sub CachePropertiesByPush(ByVal elementList As AutomationElement)
    ' Set up the request.
    Dim cacheRequest As New CacheRequest()

    ' Do not get a full reference to the cached objects, only to their cached properties and patterns.
    cacheRequest.AutomationElementMode = AutomationElementMode.None

    ' Cache all elements, regardless of whether they are control or content elements.
    cacheRequest.TreeFilter = Automation.RawViewCondition

    ' Property and pattern to cache.
    cacheRequest.Add(AutomationElement.NameProperty)
    cacheRequest.Add(SelectionItemPattern.Pattern)

    ' Activate the request.
    cacheRequest.Push()

    ' Obtain an element and cache the requested items.
    Dim myCondition As New PropertyCondition(AutomationElement.IsSelectionItemPatternAvailableProperty, _
        True)
    Dim elementListItem As AutomationElement = elementList.FindFirst(TreeScope.Children, myCondition)

    ' At this point, you could call another method that creates a CacheRequest and calls Push/Pop.
    ' While that method was retrieving automation elements, the CacheRequest set in this method 
    ' would not be active. 
    ' Deactivate the request.
    cacheRequest.Pop()

    ' Retrieve the cached property and pattern.
    Dim itemName As String = elementListItem.Cached.Name
    Dim pattern As SelectionItemPattern = _
        DirectCast(elementListItem.GetCachedPattern(SelectionItemPattern.Pattern), SelectionItemPattern)

    ' The following is an alternative way of retrieving the Name property.
    itemName = CStr(elementListItem.GetCachedPropertyValue(AutomationElement.NameProperty))

    ' This is yet another way, which returns AutomationElement.NotSupported if the element does
    ' not supply a value. If the second parameter is false, a default name is returned.
    Dim objName As Object = elementListItem.GetCachedPropertyValue(AutomationElement.NameProperty, True)
    If objName Is AutomationElement.NotSupported Then
        itemName = "Unknown"
    Else
        itemName = CStr(objName)
    End If
    ' The following call raises an exception, because only the cached properties are available, 
    '  as specified by cacheRequest.AutomationElementMode. If AutomationElementMode had its
    '  default value (Full), this call would be valid.
    '** bool enabled = elementListItem.Current.IsEnabled; **

End Sub

설명

UI 자동화 통해 속성 및 패턴을 검색하려면 성능 저하를 줄 수 있는 프로세스 간 호출이 필요합니다. 일괄 처리 작업에서 속성 및 패턴 값을 캐싱하면 애플리케이션의 성능을 향상시킬 수 있습니다.

클래스 생성자를 호출하여 새 캐시 요청을 만듭니다. 요청은 메서드에 대한 반복 호출로 Add 채워집니다.

한 CacheRequest 개만 활성화할 수 있습니다. 요청을 활성화하는 방법에는 두 가지가 있습니다.

• 요청을 호출 Activate 합니다. 이렇게 하면 요청이 스택으로 푸시되고 개체가 삭제될 때 요청이 표시됩니다. 예외가 발생하더라도 삭제하려면 using 블록 내의 Activate 반환 값(Visual Basic Using)을 사용합니다.

• 를 호출 Push하여 내부 스택에 요청을 배치합니다. 스택의 맨 위 요청만 활성 상태이며 다음 요청은 다음 요청이 스택 Pop에서 제거되어야 합니다. 요청을 표시하면 비활성화됩니다.

요청이 활성화된 동안 가져온 UI 자동화 요소에는 지정된 속성 및 패턴에 대한 캐시된 값이 있습니다.

생성자

Name	Description
CacheRequest()	CacheRequest 클래스의 새 인스턴스를 초기화합니다.

속성

Name	Description
AutomationElementMode	반환된 요소에 기본 UI(사용자 인터페이스)에 대한 전체 참조를 포함할지 캐시된 정보만 포함할지 여부를 지정하는 값을 가져오거나 설정합니다.
Current	현재 스레드에서 CacheRequest 활성 상태인 해당 스레드를 가져옵니다.
TreeFilter	캐싱할 때 사용할 UI 자동화 요소 트리의 뷰를 지정하는 값을 가져오거나 설정합니다.
TreeScope	하위 트리의 루트 또는 자식 또는 하위 항목에 대해서만 캐싱이 수행되는지 여부를 지정하는 값을 가져오거나 설정합니다.

메서드

Name	Description
Activate()	동일한 CacheRequest 스레드에서 요청된 경우 AutomationElement 반환되는 항목에 대한 활성 사양으로 설정합니다.
Add(AutomationPattern)	지정된 AutomationPattern 식별자를 이 CacheRequest식별자에 추가합니다.
Add(AutomationProperty)	지정된 AutomationProperty 식별자를 이 CacheRequest식별자에 추가합니다.
Clone()	이 CacheRequest복사본을 만듭니다.
Pop()	현재 스레드의 내부 스택에서 활성 CacheRequest 을 제거합니다.
Push()	CacheRequest 내부 상태 스택을 배치하여 현재 스레드에서 활성 요청으로 만듭니다.

추가 정보

• UI 자동화 클라이언트에서 캐싱
• UI 자동화