uniapp? JSBridge? ???? ????? ?? ???? ??? ????, ???? ?? ?? ??? ?????

1. ?? ??

??? ?????? ????? ??? ?? ???? ??? ???? ? ???? ??? ?? ???? ???. ?? ?? ???? ????. ??? ??? ??? ?????? ?? ?????? uniapp? JSBridge? ???? ?????? ?? ??? ?? ??? ? ?? ??? ??? ?????.

JSBridge? ??? ??? ???? ??? ?? ???? ???? ??? ??? ???? ???? ???? ???? ???? ?? ? ??? ?? ?? ??????. ??? ?? ?? ??? ??? ?? ??? ??? ??? ?? ????.

2. JSBridge

1. ?? ?? uniapp ????? ? js ??? ??? ??? JSBridge.js? ?????. ? ??? ??? ??? ?? ?? ?? ??? ??? ??? ???.
2. ??? ??? ???? ??? ???? ?? ??? ????? JSBridge.js ??? ?? ??? ?????. ?? ??? ??? ????.

// JSBridge.js

let messageHandlers = {}; // 存儲(chǔ)前端和原生之間的消息和回調(diào)函數(shù)

// 注冊消息處理函數(shù)，前端通過調(diào)用此函數(shù)來注冊對應(yīng)的回調(diào)函數(shù)
function registerHandler(name, handler) {
  messageHandlers[name] = handler;
}

// 發(fā)送消息到原生
function sendMessageToNative(name, data, callback) {
  let message = {
    name: name,
    data: data
  };
  
  // 注冊回調(diào)函數(shù)
  if (callback) {
    let callbackId = 'cb_' + Date.now();
    message.callbackId = callbackId;
    messageHandlers[callbackId] = callback;
  }
  
  // 向原生發(fā)送消息
  window.webkit.messageHandlers[name].postMessage(message);
}

// 處理原生發(fā)送過來的消息
function handleMessageFromNative(message) {
  let handler = messageHandlers[message.name];
  
  if (handler) {
    handler(message.data, function(response) {
      sendMessageToNative(message.callbackId, response); // 發(fā)送回調(diào)消息給原生
    });
  }
}

window.messageHandlers = messageHandlers;
window.registerHandler = registerHandler;
window.sendMessageToNative = sendMessageToNative;
window.handleMessageFromNative = handleMessageFromNative;

3. uniapp ????? main.js ??? JSBridge.js? ???? ??? ?? ??? ?????. main.js文件中引入JSBridge.js，并注冊消息處理函數(shù)，示例代碼如下：

// main.js

import JSBridge from './JSBridge.js';

// 注冊消息處理函數(shù)，前端通過調(diào)用此函數(shù)來注冊對應(yīng)的回調(diào)函數(shù)
JSBridge.registerHandler('getUserInfo', function(data, callback) {
  console.log('前端收到getUserInfo消息：', data);
  
  // 假設(shè)需要獲取用戶信息，可以通過uniapp的API來實(shí)現(xiàn)
  let userInfo = uni.getUserInfo();
  
  // 返回獲取到的用戶信息給原生
  callback(userInfo);
});

// 假設(shè)頁面上有一個(gè)按鈕，點(diǎn)擊按鈕時(shí)調(diào)用原生的方法
document.getElementById('btn').addEventListener('click', function() {
  // 發(fā)送消息到原生
  JSBridge.sendMessageToNative('showAlert', { title: 'Hello', message: 'World' });
});

4. 在原生環(huán)境中實(shí)現(xiàn)與前端交互的功能和邏輯。示例代碼如下：

// 在iOS原生代碼中

import WebKit

class ViewController: UIViewController {
  var webView: WKWebView!

  override func viewDidLoad() {
    super.viewDidLoad()
    
    // 創(chuàng)建WebView
    webView = WKWebView(frame: CGRect(x: 0, y: 0, width: view.bounds.width, height: view.bounds.height))
    view.addSubview(webView)
    
    // 加載uniapp的HTML文件
    if let url = Bundle.main.url(forResource: "uniapp", withExtension: "html") {
      webView.loadFileURL(url, allowingReadAccessTo: url)
    }
    
    // 注冊JSBridge處理函數(shù)，用于處理前端發(fā)送來的消息
    webView.configuration.userContentController.add(self, name: "getUserInfo")
    webView.configuration.userContentController.add(self, name: "showAlert")
  }
}

extension ViewController: WKScriptMessageHandler {
  func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
    if let body = message.body as? [String: Any] {
      let name = message.name
      
      if name == "getUserInfo" {
        print("原生收到getUserInfo消息：", body)
        
        // TODO: 獲取原生的用戶信息
        
        // 返回用戶信息給前端
        let userInfo = [
          "name": "John",
          "age": 20
        ]
        let response = [
          "data": userInfo
        ]
        let javascript = "window.handleMessageFromNative((response))"
        webView.evaluateJavaScript(javascript, completionHandler: nil)
      }
      else if name == "showAlert" {
        print("原生收到showAlert消息：", body)
        
        // 假設(shè)實(shí)現(xiàn)一個(gè)彈窗功能
        let title = body["title"] as? String ?? ""
        let message = body["message"] as? String ?? ""
        let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
        alertController.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
        present(alertController, animated: true, completion: nil)
      }
    }
  }
}

三、使用JSBridge進(jìn)行前端與原生交互

通過上述的步驟，我們已經(jīng)實(shí)現(xiàn)了基本的JSBridge橋梁和消息處理函數(shù)。在前端代碼中，我們可以調(diào)用JSBridge.sendMessageToNative()方法向原生發(fā)送消息，同時(shí)也可以注冊對應(yīng)的消息處理函數(shù)，如示例中的JSBridge.registerHandler()。在原生代碼中，我們通過userContentController.add()方法注冊處理函數(shù)，用于接收前端發(fā)送的消息，并實(shí)現(xiàn)相應(yīng)的功能。

在頁面中，當(dāng)點(diǎn)擊按鈕時(shí)，調(diào)用JSBridge.sendMessageToNative('showAlert', { title: 'Hello', message: 'World' })方法發(fā)送消息到原生，原生接收到消息后，彈出一個(gè)帶有標(biāo)題和內(nèi)容的彈窗。另外，當(dāng)前端需要獲取用戶信息時(shí)，調(diào)用JSBridge.sendMessageToNative('getUserInfo')

?????? ?????? ??? ??? ???? ???? ??????. ?? ??? ??? ????.

rrreee

3. ??? ?? ? ???? ?? ??? ?? JSBridge? ?????. ????? ??? ?? ?? JSBridge ??? ? ??? ?? ??? ??????. ????? ???? JSBridge.sendMessageToNative() ???? ???? ????? ???? ?? ? ??? JSBridge.registerHandler()? ?? ?? ??? ?? ??? ??? ?? ????. ????. ???? ????? userContentController.add() ???? ?? ??? ???? ?? ???? ???? ?? ??? ???? ?? ??? ?????. ????????? ??? ???? JSBridge.sendMessageToNative('showAlert', { title: 'Hello', message: 'World' }) ???? ???? ???? ???? ??? ??? ??? ?? ???? ???. ?? ??????? ??? ??? ???? ?? ?? JSBridge.sendMessageToNative('getUserInfo') ???? ???? ????? ???? ????. ?????? ?? ??? ?? ???? ??? ?????. ????????? JSBridge? ???? uniapp? ???? ?? ?? ?? ??? ?? ??? ? ??? ?? ??? ??? ?????? ?? ??? ??? ??? ? ????. ??? ?? ??? ???? ???? ???? ???? ??? ? ????. ????? ??? JSBridge? ???? ???? ????? ???? uniapp? ?? ??? ??? ?? ?????. ??

? ??? uniapp ??? ??? JSBridge? ???? ????? ?? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!