Swift - RxSwift的使用详解28（UI控件扩展7：UIGestureRecognizer）

2018-03-02 发布：hangge 阅读：5001

七、UIGestureRecognizer

RxCocoa 同样对 UIGestureRecognizer 进行了扩展，并增加相关的响应方法。下面以滑动手势为例，其它手势用法也是一样的。

1，效果图

当手指在界面上向上滑动时，弹出提示框，并显示出滑动起点的坐标。

2，样例代码

（1）第一种响应回调的写法

import UIKit
import RxSwift
import RxCocoa

class ViewController: UIViewController {
    
    
    let disposeBag = DisposeBag()
    
    override func viewDidLoad() {
        super.viewDidLoad()

        //添加一个上滑手势
        let swipe = UISwipeGestureRecognizer()
        swipe.direction = .up
        self.view.addGestureRecognizer(swipe)
        
        //手势响应
        swipe.rx.event
            .subscribe(onNext: { [weak self] recognizer in
                //这个点是滑动的起点
                let point = recognizer.location(in: recognizer.view)
                self?.showAlert(title: "向上划动", message: "\(point.x) \(point.y)")
            })
            .disposed(by: disposeBag)
    }
    
    //显示消息提示框
    func showAlert(title: String, message: String) {
        let alert = UIAlertController(title: title, message: message,
                                      preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "确定", style: .cancel))
        self.present(alert, animated: true)
    }
}

（2）第二种响应回调的写法

import UIKit
import RxSwift
import RxCocoa

class ViewController: UIViewController {
    
    
    let disposeBag = DisposeBag()
    
    override func viewDidLoad() {
        super.viewDidLoad()

        //添加一个上滑手势
        let swipe = UISwipeGestureRecognizer()
        swipe.direction = .up
        self.view.addGestureRecognizer(swipe)
        
        //手势响应
        swipe.rx.event
            .bind { [weak self] recognizer in
                //这个点是滑动的起点
                let point = recognizer.location(in: recognizer.view)
                self?.showAlert(title: "向上划动", message: "\(point.x) \(point.y)")
            }
            .disposed(by: disposeBag)
    }
    
    //显示消息提示框
    func showAlert(title: String, message: String) {
        let alert = UIAlertController(title: title, message: message,
                                      preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "确定", style: .cancel))
        self.present(alert, animated: true)
    }
}

附：实现点击页面任意位置，输入框便失去焦点

import UIKit
import RxSwift
import RxCocoa

class ViewController: UIViewController {
    let disposeBag = DisposeBag()
    
    override func viewDidLoad() {
        super.viewDidLoad()
      
        //添加一个点击手势
        let tapBackground = UITapGestureRecognizer()
        view.addGestureRecognizer(tapBackground)

        //页面上任意处点击，输入框便失去焦点
        tapBackground.rx.event
            .subscribe(onNext: { [weak self] _ in
                self?.view.endEditing(true)
            })
            .disposed(by: disposeBag)
    }
}