TextPointer.GetPointerContext(LogicalDirection) 方法

定義

傳回指定邏輯方向中目前 TextPointer 相鄰內容的類別指標。

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

LogicalDirection其中一個值指定了決定相鄰內容類別的邏輯方向。

傳回

TextPointerContext其中一個值表示在指定邏輯方向相鄰內容的類別。

範例

以下範例展示了此方法的應用。 本範例使用此 GetPointerContext 方法實作一個演算法,計算兩個指定 TextPointer 位置間開閉元素標籤的平衡。 每個開頭元素標籤計算為 +1,每個結尾元素標籤計算為 -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

適用於