wpf richtextbox检查插入符号是否在最后一行或计算它有多少行

Question

我想在富文本框中找出插入符号是否位于最后一行。这可能吗？

注意：最后我还补充道：或者统计它有多少行，这是因为在miscrosoft论坛中有一个用于检测插入符号在哪一行的示例。

谢谢

Answer 1

我找到了解决办法。也许还有一个更简单的方法，如果是的话请让我知道

private void OnHasRtbReachedEnd(System.Windows.Controls.RichTextBox rtb) 
    { 
     TextPointer pointer1 = rtb.CaretPosition; 
     int iCurrentLine = GetLineNumber(rtb); 
     rtb.CaretPosition = rtb.Document.ContentEnd; 
     int iLastLine = GetLineNumber(rtb); 

     if (iCurrentLine == iLastLine) 
     { 
      if (!_bIsRtbMovingUpDown) 
       MoveToNextDataGridRow(); 
      _bIsRtbMovingUpDown= false; 
     } 
     else 
     { 
      _bIsRtbMovingUpDown= true; 
     } 
     rtb.CaretPosition = pointer1; 
    } 

//此代码来自 // http://social.msdn.microsoft.com/Forums/en/wpf/thread/667b5d2a-84c3-4bc0-a6c0-33f9933db07f

private int GetLineNumber(System.Windows.Controls.RichTextBox rtb) 
    { 
     TextPointer caretLineStart = rtb.CaretPosition.GetLineStartPosition(0); 
     TextPointer p = rtb.Document.ContentStart.GetLineStartPosition(0); 
     int caretLineNumber = 1; 

     while (true) 
     { 
      if (caretLineStart.CompareTo(p) < 0) 
      { 
       break; 
      } 

      int result; 
      p = p.GetLineStartPosition(1, out result); 

      if (result == 0) 
      { 
       break; 
      } 

      caretLineNumber++; 
     } 
     return caretLineNumber; 

    } 

Answer 2

请核实MSDN链接

http://social.msdn.microsoft.com/Forums/en/wpf/thread/667b5d2a-84c3-4bc0-a6c0-33f9933db07f

如果你真的想知道脱字符的行号，你可以做类似下面的事情（可能需要一些twea王）：

TextPointer caretLineStart = rtb.CaretPosition.GetLineStartPosition(0); 
TextPointer p = rtb.Document.ContentStart.GetLineStartPosition(0); 
int caretLineNumber = 1; 

while (true) 
{ 
    if (caretLineStart.CompareTo(p) < 0) 
    { 
     break; 
    } 

    int result; 
    p = p.GetLineStartPosition(1, out result); 

    if (result == 0) 
    { 
     break; 
    } 

    caretLineNumber++; 
} 

Answer 3

代码即可获得行数：

Int32 CountDisplayedLines(RichTextBox rtb) 
{ 
    Int32 result = -1; 

    rtb.CaretPosition = rtb.Document.ContentStart; 

    while (rtb.CaretPosition.GetLineStartPosition(++result) != null) 
    { 
    } 

    return result; 
} 

Answer 4

我试过的代码，而不是总是给正确的结果。 一个聪明的办法来做到这一点是这个

int previousCursorPosition; 
    private void RichTarget_KeyDown_1(object sender, KeyEventArgs e) 
    { 
     if (e.Key == Key.Up || e.Key == Key.Down) 
     { 
      Xceed.Wpf.Toolkit.RichTextBox rich = (Xceed.Wpf.Toolkit.RichTextBox)sender; 
      previousCursorPosition = rich.CaretPosition.GetOffsetToPosition(rich.CaretPosition.DocumentStart); 
     } 
    } 
    private void RichTextBox_KeyUp_1(object sender, KeyEventArgs e) 
    { 

      if (e.Key == Key.Up) 
      { 
       Xceed.Wpf.Toolkit.RichTextBox rich = (Xceed.Wpf.Toolkit.RichTextBox)sender; 

       if (previousCursorPosition == rich.CaretPosition.GetOffsetToPosition(rich.CaretPosition.DocumentStart)) 
       { 
        //do your staff 

       } 

      } 
      else if (e.Key == Key.Down) 
      { 
       Xceed.Wpf.Toolkit.RichTextBox rich = (Xceed.Wpf.Toolkit.RichTextBox)sender; 
       if (previousCursorPosition == rich.CaretPosition.GetOffsetToPosition(rich.CaretPosition.DocumentStart)) 
       { 
        //do your staff 
       } 
      } 


    }