[原创]c#巧用鼠标的状态图标修改给人错觉实现拖拽修改

原理就是鼠标移动到边界的时候就修改鼠标状态
如果按下则把移动标记打开，抬起或者离开则把鼠标标记再锁上，
移动到有效位置图标也修改了，所以错觉完成了一个拖拽功能。

private void panel_keyboard_head_MouseUp(object sender, MouseEventArgs e)
        {
            this.Cursor = Cursors.Default;
            LogUtil.writeLog("鼠标抬起了。");
            mEnableMoveFlag = false;
        }

        private void panel_keyboard_head_MouseMove(object sender, MouseEventArgs e)
        {
        
            this.Cursor = Cursors.Default;
            Control control = (Control)sender;
            if (locationIsAtKeyboardEdge(e, panel_keyboard_head.Height))
            {
                this.Cursor = Cursors.SizeNS;
                LogUtil.writeLog("位置正确。");
                //mEnableMoveFlag = true;
            }
            else
            {
                LogUtil.writeLog("位置不正确。");
                this.Cursor = Cursors.Default;
            }

            if (mEnableMoveFlag)
            {
                panel_keyboard_head.Height = e.Y;
                keyboard.keyboardHeader.getHeight().setValue(e.Y);
                updateKeybaordBodyAndHeadHeight();
                if (mAutoChangeMode)
                {
                    jsonObject2Text();
                }
            }
            else
            {
                LogUtil.writeLog("处于锁定状态 等待设置，等待按下");
            }
        }

        private void panel_keyboard_head_MouseDown(object sender, MouseEventArgs e)
        {
            if (this.Cursor == Cursors.SizeNS)
            {
                LogUtil.writeLog("属于有效区域 允许拖拽");
                mEnableMoveFlag = true;
            }
            else
            {
                LogUtil.writeLog("按下但是不是有效区域 不允许拖拽");
            }




        }

        private void panel_keyboard_head_MouseLeave(object sender, EventArgs e)
        {
            this.Cursor = Cursors.Default;
            mEnableMoveFlag = false;
            LogUtil.writeLog("鼠标松开了。");

边界判断

public bool locationIsAtKeyboardEdge(MouseEventArgs e,int locationY)
        {
            //int totalHeight = tabPage_preview_phone_height.Height;
            //int top = totalHeight - panel_keyboard.Height;
            //Cursor.Current = new Cursor(@"C:\my.cur");
            //OR: Cursor Cur = new Cursor(@"C:\my.cur");
            //this.Cursor = Cur；
            int distance = e.Y - locationY;
            if (Math.Abs(distance) > 3)
            {
                //    LogUtil.writeLog("逻辑不成立 top");
                return false;
            }
            else
            {
                //  LogUtil.writeLog("逻辑成立 相差" + distance);
                return true;
            }


        }

和安卓一样，这个坐标体系也差不多,x 代表的是在于父容器自身的x距离。

image.png