编写应用程序，当鼠标进入窗口时，用一个文本框给出鼠标进入或离开的信息，当鼠标左键按下拖拽时，文本框给出鼠标所在点的坐标-Written application, when the mouse enters the window, a text box with the mouse enters or leaves given the information, press the left mouse button when dragging, the text box where the point given the coordinates of the mouse