在swift 5中，你可以使用以下代码来解除文本域外的键盘

override func viewDidLoad() {
    // ... code

    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.dismissKeyboard(_:)))
    self.view.addGestureRecognizer(tapGesture)  
}

@objc func dismissKeyboard(_ sender: UITapGestureRecognizer) {
    self.view.endEditing(true)
}

你需要添加一个UITapGestureRecogniser并将其分配给视图，然后在它的选择器上的UITextField上调用resign first responder。

代码:

在viewDidLoad

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

[self.view addGestureRecognizer:tap];

在dismissKeyboard:

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

(其中，aTextField是负责键盘的文本字段)

Swift 3版本是这样的

let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.dismissKeyboard (_:)))
self.view.addGestureRecognizer(tapGesture)

对于dismissKeyboard

@objc func dismissKeyboard (_ sender: UITapGestureRecognizer) {
    aTextField.resignFirstResponder()
}

只是使用这段代码在您的.m文件，它将辞职的文本字段，当用户点击文本字段之外。

 -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
  [textfield resignFirstResponder];
 }

你可以使用UITapGestureRecongnizer方法通过点击UITextField之外的按钮来取消键盘。通过使用这个方法，每当用户在UITextField之外点击时，键盘就会被驳回。下面是使用它的代码片段。

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

    [self.view addGestureRecognizer:tap];


//Method
- (void) dismissk
{
    [abctextfield resignFirstResponder];
    [deftextfield resignFirstResponder];

}

这个怎么样:我知道这是一个老帖子。它可能会帮助某些人:)

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {  
    NSArray *subviews = [self.view subviews];
    for (id objects in subviews) {
        if ([objects isKindOfClass:[UITextField class]]) {
            UITextField *theTextField = objects;
            if ([objects isFirstResponder]) {
                [theTextField resignFirstResponder];
            }
        } 
    }
}

最简单和最短的方法之一是将此代码添加到viewDidLoad

[self.view addGestureRecognizer:[[UITapGestureRecognizer alloc]
                                     initWithTarget:self.view
                                     action:@selector(endEditing:)]];