只是在这里添加我的版本如何在外部触摸时取消键盘。

viewDidLoad:

UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
[self.view addGestureRecognizer:singleTap];

在任何地方:

-(void)handleSingleTap:(UITapGestureRecognizer *)sender{
    [textFieldName resignFirstResponder];
    puts("Dismissed the keyboard");
}

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)
}

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    super.view.endEditing(true)
    super.touchesBegan(touches, withEvent: event)
}

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:)]];

这是

在本例中，aTextField是唯一的UITextField....如果有其他的uitextview，还有一点点事情要做。

// YourViewController.h
// ...
@interface YourViewController : UIViewController /* some subclass of UIViewController */ <UITextFieldDelegate> // <-- add this protocol
// ...
@end

// YourViewController.m

@interface YourViewController ()
@property (nonatomic, strong, readonly) UITapGestureRecognizer *singleTapRecognizer;
@end
// ...

@implementation
@synthesize singleTapRecognizer = _singleTapRecognizer;
// ...

- (void)viewDidLoad
{
    [super viewDidLoad];
    // your other init code here
    [self.view addGestureRecognizer:self.singleTapRecognizer];

{

- (UITapGestureRecognizer *)singleTapRecognizer
{
    if (nil == _singleTapRecognizer) {
        _singleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTapToDismissKeyboard:)];
        _singleTapRecognizer.cancelsTouchesInView = NO; // absolutely required, otherwise "tap" eats events.
    }
    return _singleTapRecognizer;
}

// Something inside this VC's view was tapped (except the navbar/toolbar)
- (void)singleTapToDismissKeyboard:(UITapGestureRecognizer *)sender
{
    NSLog(@"singleTap");
    [self hideKeyboard:sender];
}

// When the "Return" key is pressed on the on-screen keyboard, hide the keyboard.
// for protocol UITextFieldDelegate
- (BOOL)textFieldShouldReturn:(UITextField*)textField
{
    NSLog(@"Return pressed");
    [self hideKeyboard:textField];
    return YES;
}

- (IBAction)hideKeyboard:(id)sender
{
    // Just call resignFirstResponder on all UITextFields and UITextViews in this VC
    // Why? Because it works and checking which one was last active gets messy.
    [aTextField resignFirstResponder];
    NSLog(@"keyboard hidden");
}

在viewDidLoad 斯威夫特4.2 代码是这样的

let viewTap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action:#selector(dismissKeyboard))
        view.addGestureRecognizer(viewTap)
@objc func dismissKeyboard() {
        view.endEditing(true)
    }