I want to use the lineedit in the bottom of the window to show the row number whcih is selected by the user! But the number is not always right.If u select the row just by one mouse btn click, the number is right. If u select the rows by pushdown your left mouse btn and draw diagonal line of a rectangel,then release the button, the rows in the rectangel would be selected, but the number which is showed in the lineedit is totally wrong.
Together with my original post, I hope I make myself clear.