ios 收键盘keyboard touch outside

https://stackoverflow.com/questions/5306240/iphone-dismiss-keyboard-when-touching-outside-of-uitextfield

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissKeyboard)];

[self.view addGestureRecognizer:tap];

-(void)dismissKeyboard 
{
    [aTextField resignFirstResponder];
}

最外层view哪里来？
2个办法：
1.传入
2.专门写一个baseKeyboardViewController来处理键盘事件，需要做收键盘的ViewController，应该都继承这个ViewController

第二种：收textfeild外的键盘

@property (nonatomic, strong) UIGestureRecognizer *tapGesture;
self.tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(editAreaHidden)];

• (void) editAreaHidden {
  [self.nameTextField resignFirstResponder];
  }

-(void) textFieldDidBeginEditing:(UITextField *)textField {
[self.view addGestureRecognizer:self.tapGesture];
}
-(void) textFieldDidEndEditing:(UITextField *)textField {
[self.view removeGestureRecognizer:self.tapGesture];
}