我需要向用户显示，像NOTEPAD.EXE，选择开始和他对光标文字的长度。

选择长度是没有问题的，因为RichTextBox的支持选择属性开始和结束。

http://msdn.microsoft.com/en-us/library/system.windows.documents.textpointer.getoffsettoposition.aspx

但我RichTexbox的startIndex是永远 2 而不是 0 ，如果我设置的第一个位置的光标该文档。 如果我清楚完整的文字是在 0 。但是，如果我preSS SPACE 然后退格的文本框为空，但开始索引的计数器上的 2

你知道吗？

*编辑* 第一个解决方案

好了，这就是我的工作液。但是，我认为这是一个更好的办法来做到这一点。

 '''＆LT;总结＆gt;
    '''获取光标的位置。忽略所有格式字符，如回车和段落。只是计数可见字符。
    '''＆LT; /总结＆gt;
    '''＆LT; PARAM NAME =RTB＆gt;将RichTextBox的值应确定和LT; /参数＆GT;
    '''＆LT;返回＆gt;将光标的指标值。 0是在所述第一位置。后位置的背后是字符123，它会返回该指数3＆LT; /回报＆GT;
    '''＆LT;说明＆GT;提防的表现，分开使用此梅索德。蒂莫·鲍姆（Böhme），2012＆LT; /说明＆GT;
    专用功能GetPositionOfCursor（BYVAL RTB作为RichTextBox中）作为整数
        昏暗contentStart作为TextPointer = rtb.Document.ContentStart
        昏暗的资源为整数= 0
        昏暗CursorIndex作为整数= contentStart.GetOffsetToPosition（rtb.CaretPosition）
        昏暗Ĵ作为整数= 0

        做
            如果J＆GT; CursorIndex然后退出待办事项
            如果contentStart.GetPositionAtOffset（1，LogicalDirection.Forward）是没有那么
                退出待办事项
            elseif的contentStart.GetPointerContext（LogicalDirection.Backward）= TextPointerContext.Text然后
                RES + = 1
            结束如果

            contentStart = contentStart.GetPositionAtOffset（1，LogicalDirection.Forward）
            J + 1 =
        循环

        返回水库
    端功能
 

解决方案

我不知道这是否是一个真正的回答你的问题，但我用这个简单的技巧来获取TOT文本相关的光标指数：

的TextRange范围=新的TextRange（Document.ContentStart，CaretPosition）; INT N = range.Text.Length;

我工作的基础上，WPF的RichTextBox的编辑器。由于实时的格式（如突出的关键字等等）实在是太慢了我创建另一个线程一个新的文档。在这个线程的文字被格式化为appropiate运行，而不是将它们作为格式在RichTextBox的段落中的一部分。一旦完成了原来的被替换为新的。作品真的很好，令人难以置信的速度快（与MS的方法至少）。

我希望这能给你一些启发和/或想法。

I need to show the user, like in notepad.exe, the selection start and length of his text on cursor.

Selection length is no problem because Richtextbox supports the Selection Property with Start and End.

http://msdn.microsoft.com/en-us/library/system.windows.documents.textpointer.getoffsettoposition.aspx

But the startindex of my RichTexbox is always 2 instead of 0 if I set the cursor on first position of the document. If I CLEAR the complete text it is on 0. But if I press SPACE and then BACKSPACE the textbox is empty but the counter of StartIndex is on 2

Any idea?

* EDIT * FIRST SOLUTION

Ok, thats a working solution of mine. But I think there is a better way to do it.

''' <summary>
    ''' Get the position of the cursor. Ignores all formatting characters like ENTER and PARAGRAPH. Just counts the visible characters.
    ''' </summary>
    ''' <param name="rtb">The richtextbox the value should be determined</param>
    ''' <returns>Index value of the cursor. 0 is at the first position. After position is behind characters "123" it would return the index 3.</returns>
    ''' <remarks>Watch out for performance, Use this methode in separated. Timo Böhme, 2012</remarks>
    Private Function GetPositionOfCursor(ByVal rtb As RichTextBox) As Integer
        Dim contentStart As TextPointer = rtb.Document.ContentStart
        Dim res As Integer = 0
        Dim CursorIndex As Integer = contentStart.GetOffsetToPosition(rtb.CaretPosition)
        Dim j As Integer = 0

        Do
            If j > CursorIndex Then Exit Do
            If contentStart.GetPositionAtOffset(1, LogicalDirection.Forward) Is Nothing Then
                Exit Do
            ElseIf contentStart.GetPointerContext(LogicalDirection.Backward) = TextPointerContext.Text Then
                res += 1
            End If

            contentStart = contentStart.GetPositionAtOffset(1, LogicalDirection.Forward)
            j += 1
        Loop

        Return res
    End Function

I do not know whether this is a real answer to your question, but I use this simple trick to retrieve the cursor index related tot the text:

TextRange range = new TextRange(Document.ContentStart, CaretPosition); int n = range.Text.Length;

I'm working on an editor based on the WPF richtextbox. Since real time formatting (like highlighting keywords and such) is really slow I create a new document in another thread. In this thread the text gets formatted in appropiate runs, rather than formatting them as a part of the richtextbox's paragraph. Once finished the original one is replaced by the new one. Works really nice and incredible fast (compared to the MS way at least).

I hope this give you some inspiration and/or ideas.