Question

我需要编写一个C＃程序，它将识别光标下的窗口并在其上绘制边框。

我可以轻松获得一个Windows处理程序：

...
Point point;
WinApi.GetCursorPos(out point);
WinApi.WindowFromPoint(point);
...

但是我无法在那个窗口上画画......

public static void drawSelectionRectangle(IntPtr handler)
{
    Rectangle rectangle;
    WinApi.GetWindowRect(handler, out rectangle);

    WinApi.PAINTSTRUCT paintProperties;
    IntPtr paintContext = WinApi.BeginPaint(handler, out paintProperties);

    IntPtr pen = WinApi.CreatePen(WinApi.PenStyle.PS_SOLID, 5, (uint) ColorTranslator.ToWin32(Color.Red));
    WinApi.SelectObject(paintContext, pen);

    WinApi.Rectangle(paintContext, rectangle.Left, rectangle.Top, rectangle.Right, rectangle.Bottom);

    WinApi.ValidateRect(handler, IntPtr.Zero);
    WinApi.EndPaint(handler, ref paintProperties);
}

我调用drawSelectionRectangle(IntPtr handler)一次（通过按钮点击）和循环（通过MyForm的onPaint()方法，而不是我想要绘制的形式）。这似乎不起作用。

请帮帮我。我不知道该怎么做。

Answer 1

这不是我的问题的完整解决方案，但它是有效的。

我想在目标窗口上绘图（如果目标窗口位于其他窗口下方，边框也必须位于其他窗口下方）...但是解决方案（当边框绘制在所有窗口之上时）总比没有好。

我希望我的问题和解决方案可以帮助某人。谢谢大家^ _ ^。

public partial class Form1 : Form
{
    private IntPtr selectedWindowHandler;    

    ...

    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
        Cursor.Current = new Cursor(Properties.Resources.aimImage.GetHicon());
        mousePressed = true;
        pictureBox_aimImage.Invalidate();
    }

    private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
    { 
        mousePressed = false;
        invalidateAllWindows();
    }

    // this method for pictureBox1 which contain custom cursor
    // to choose window for draw border you must click on this box 
    // and drag to targwt window
    private void pictureBox1_Paint(object sender, PaintEventArgs e)
    {
        if (mousePressed)
        {
            Point point;
            WinApi.GetCursorPos(out point);
            IntPtr hWnd = Window.getHandler(point);

            if (hWnd.Equals(selectedWindowHandler))
            {                    
                drawSelectionRectangle(selectedWindowHandler);
                pictureBox_aimImage.Invalidate();
            } else
            {
                selectedWindowHandler = hWnd;
                invalidateAllWindows();
            }
        }
    }

    // when i once called InvalidateRect(...) not all border was cleared
    // i don't know why
    private static void invalidateAllWindows()
    {
        WinApi.InvalidateRect(IntPtr.Zero, IntPtr.Zero, true);
        WinApi.InvalidateRect(IntPtr.Zero, IntPtr.Zero, true);
        WinApi.InvalidateRect(IntPtr.Zero, IntPtr.Zero, true);
    }     

    ...

    public static Rectangle getRectangle(IntPtr handler)
    {
        Rectangle rectangle;
        WinApi.GetWindowRect(handler, out rectangle);
        rectangle = new Rectangle(
            rectangle.Location,
            new Size(
                rectangle.Size.Width - rectangle.Location.X,
                rectangle.Size.Height - rectangle.Location.Y
            )
        );
        return rectangle;
    }

    public static void drawSelectionRectangle(IntPtr handler)
    {           
        //getting target window rectangle for GDI+
        Rectangle rect = getRectangle(handler);

        //getting context of desktop
        Graphics g = Graphics.FromHwnd(IntPtr.Zero);
        using (g)
        {
            //drawing borders
            g.DrawRectangle(new Pen(Color.Red, 3), rect);
        }
    }

}

C＃。 WINAPI。画在窗口上

1 个答案: