1.VC中重载touchesBegain事件，然后在里面执行：[self.view endEditing:YES]

2.如果不方便取到当前view，可以使用[[UIApplication sharedApplication] sendAction:@selector(resignFirstResponser) to:nil from:nil forEvent:nil];

3.[[[UIApplication sharedApplication] keyWindow] endEditing:YES];