SendScintilla(SCI_POINTXFROMPOSITION, position);

上面写法是不对的

//注意,case SCI_POINTXFROMPOSITION: 那儿用的是lParam参数,而没有用wParam
 //而最外层函数有两种形式SendScintilla(unsigned int msg, long wParam)
 //SendScintilla(unsigned int msg, unsigned long wParam = 0,long lParam = 0)
 //也就是说最外层的函数必须要调用第二个才行,也就是wParam参数我们一定得调用时给个0所以,容易掉入陷阱,要特别注意。正确的写法如下:
QPoint Editor::getPointXYFromPostion(int position)
 {
    int x = SendScintilla(SCI_POINTXFROMPOSITION, 0, position);
     int y = SendScintilla(SCI_POINTYFROMPOSITION, 0, position);
 //    y -= textHeight(getLineFromPosition(position)); 
     return QPoint(x, y);
 }