编写一个Windows应用程序，要求在窗口的用户区绘制一个圆，当单击左键时，该圆放大；单击右键时，该圆缩小；按下Ctrl键的同时移动鼠标修改版，完善上次的bug

[{"title":"（ 128 个子文件 45.13MB ） 编写一个Windows应用程序，要求在窗口的用户区绘制一个圆，当单击左键时，该圆放大；单击右键时，该圆缩小；按下Ctrl键的同时移动鼠标修改版，完善上次的bug","children":[{"title":"test2.exe <span style='color:#111;'> 398.00KB </span>","children":null,"spread":false},{"title":"test2.ilk <span style='color:#111;'> 2.81MB </span>","children":null,"spread":false},{"title":"test2.pdb <span style='color:#111;'> 5.51MB </span>","children":null,"spread":false},{"title":"test2.sdf <span style='color:#111;'> 62.52MB </span>","children":null,"spread":false},{"title":"test2.suo <span style='color:#111;'> 15.00KB </span>","children":null,"spread":false},{"title":"......","children":null,"spread":false},{"title":"<span style='color:steelblue;'>文件过多，未全部展示</span>","children":null,"spread":false}],"spread":true}]