TextPointer.GetPointerContext(LogicalDirection) 方法

定義

命名空間:

System.Windows.Documents

組件:

PresentationFramework.dll

針對在指定的邏輯方向中與目前 TextPointer 相鄰的內容，傳回分類指示器。

public:
 System::Windows::Documents::TextPointerContext GetPointerContext(System::Windows::Documents::LogicalDirection direction);

public System.Windows.Documents.TextPointerContext GetPointerContext (System.Windows.Documents.LogicalDirection direction);

member this.GetPointerContext : System.Windows.Documents.LogicalDirection -> System.Windows.Documents.TextPointerContext

Public Function GetPointerContext (direction As LogicalDirection) As TextPointerContext

參數

direction

LogicalDirection

其中一個 LogicalDirection 值，這個值會指定將在哪一個邏輯方向中判斷相鄰內容的分類。

傳回

TextPointerContext

其中一個 TextPointerContext 值，這個值會指出在指定的邏輯方向中相鄰內容的分類。

範例

下列範例示範這個方法的用法。 此範例會 GetPointerContext 使用 方法來實作演算法，以計算兩個指定 TextPointer 位置之間開頭和結尾專案標記的平衡。 每個開頭元素標籤都會計算為 +1，而每個結尾元素標籤都會計算為 -1。

// Calculate and return the relative balance of opening and closing element tags
// between two specified TextPointers.
int GetElementTagBalance(TextPointer start, TextPointer end)
{
    int balance = 0;
 
    while (start != null && start.CompareTo(end) < 0)
    {
        TextPointerContext forwardContext = start.GetPointerContext(LogicalDirection.Forward);
 
        if (forwardContext == TextPointerContext.ElementStart)     balance++;
        else if (forwardContext == TextPointerContext.ElementEnd)  balance--;
             
        start = start.GetNextContextPosition(LogicalDirection.Forward);
    } // End while.
 
    return balance;
} // End GetElementTagBalance

' Calculate and return the relative balance of opening and closing element tags
' between two specified TextPointers.
Private Function GetElementTagBalance(ByVal start As TextPointer, ByVal [end] As TextPointer) As Integer
    Dim balance As Integer = 0

    Do While start IsNot Nothing AndAlso start.CompareTo([end]) < 0
        Dim forwardContext As TextPointerContext = start.GetPointerContext(LogicalDirection.Forward)

        If forwardContext = TextPointerContext.ElementStart Then
            balance += 1
        ElseIf forwardContext = TextPointerContext.ElementEnd Then
            balance -= 1
        End If

        start = start.GetNextContextPosition(LogicalDirection.Forward)

    Loop ' End while.

    Return balance

End Function ' End GetElementTagBalance