用notepad画图蛮好玩的看我MVC设计模式图

			 _______________________________________
			|					|
			|					|
			|					|<-------------------accept user input
			|		Controller		|
			|					|
			|_______________________________________|
			 	|			|
				|			|				 0
			 	|			|				/|\
				|			|				/ \
			 	|			|
				|			|
		________________V_______         _______V___________________
		|			|	|			    |
		|			|	|			    |
		|	Modal		|	|	  View 		    |<-------output to screens
		|			|<------|			    |
		|			|	|			    |
		|_______________________|	|___________________________|
什么时候用这个画用例图估计更好玩