【代码笔记】iOS-清除缓存有黑色背景（仿环球时报)

一，效果图。

二，代码。

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{    UIAlertView * alterView = [[UIAlertView alloc]initWithTitle:@"提示" message:@"以清除缓存" delegate:self cancelButtonTitle:nil otherButtonTitles:@"确认", nil];    [alterView show];}