iOS ViewController点击空白处收起键盘

点击ViewController空白处时收起键盘，可以通过系统的touchesBegan方法实现，具体如下：

Objective-C 版

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {    [self.view endEditing:YES];}

Swift 版

// 收起键盘override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {    self.view.endEditing(true)}