iOS和JS互调--WebViewJavascriptBridge使用说明

在App中，会碰到使用webview，嵌入HTML，然手需要与JS互调的需求。
下面来说一下WebViewJavascriptBridge在ios端怎么样使用。
1.Objective-C初始化

UIWebView* webView = [[UIWebView alloc] initWithFrame:self.view.bounds];    [self.view addSubview:webView];

2.将此webview与WebViewJavascriptBridge关联（viewdidload）

if (_bridge) {    return; }[WebViewJavascriptBridge enableLogging];_bridge = [WebViewJavascriptBridge bridgeForWebView:webView webViewDelegate:self handler:^(id data, WVJBResponseCallback responseCallback) {    NSLog(@"ObjC received message from JS: %@", data);    responseCallback(@"Response for message from ObjC");  }];

3.JavaScript 初始化

function connectWebViewJavascriptBridge(callback) {    if (window.WebViewJavascriptBridge) {        callback(WebViewJavascriptBridge);    } else {        document.addEventListener('WebViewJavascriptBridgeReady', function() {callback(WebViewJavascriptBridge);}, false);    }}connectWebViewJavascriptBridge(function(bridge) {    bridge.init(function(message, responseCallback) {            log('JS got a message', message)            var data = { 'Javascript Responds':'Wee!' }            log('JS responding with', data)            responseCallback(data)    })});

这里初始化先是创建了一个connectWebViewJavascriptBridge方法，该方法注册了一个WebViewJavascriptBridgeReady事件，同时声明了一个全局的WebViewJavascriptBridge变量。我们可以在外部通过WebViewJavascriptBridge调用相关方法。

在init里面同样有一个function，这个function同样是用来接收Objective-C里面通过send方法发送的消息的，参数与OC里的send方法参数对应

4.Objective-C调用JavaScript
首先要在JavaScript里面注册一个方法：

bridge.registerHandler('showChat', function(data, responseCallback) {    log('ObjC called showChat with', data)    var responseData = { 'Javascript Says':'Right back atcha!' }    log('JS responding with', responseData)    responseCallback(responseData)})

OC调用这个方法

[_bridge callHandler:@"showChat" data:data responseCallback:^(id response) {        NSLog(@"showChat responded: %@", response); }];

5.JavaScript调用Objective-C
OC注册一个方法：

[_bridge registerHandler:@"showChat" handler:^(id data, WVJBResponseCallback responseCallback) {        NSLog(@"showChat called: %@", data);        responseCallback(@"Response from showChat"); }];

JavaScript调用方法

bridge.callHandler('showChat', {'foo': 'bar'}, function(response) {    log('JS got response', response)});

6.JavaScript向OC中发送消息

bridge.send(data, function(responseData) {    log('JS got response', responseData)});

这种方式发送消息实际上是调用了OC初始化时的handle

7.OC向JavaScript发送消息

[_bridge send:@"A string sent from ObjC before Webview has loaded." responseCallback:^(id responseData) {        NSLog(@"objc got response! %@", responseData);}];

这个send方法，实际上是调用了JavaScript初始化init里面的function

附上我们应用中app.js的完整代码

function connectWebViewJavascriptBridge(callback) {    if (window.WebViewJavascriptBridge) {        callback(WebViewJavascriptBridge)    } else {        document.addEventListener('WebViewJavascriptBridgeReady', function() {            callback(WebViewJavascriptBridge)        }, false)    }}connectWebViewJavascriptBridge(function(bridge) {    /* Init your app here */    bridge.init(function(message, responseCallback) {        alert('Received message: ' + message)           if (responseCallback) {            responseCallback("Right back atcha")        }    })    // 向oc发消息    bridge.send('Hello from the javascript')    bridge.send('response to xxx', function responseCallback(responseData) {        console.log("Javascript got its response", responseData)    })    // js调用oc方法    var callbackButton = document.getElementById('callbackButton');    callbackButton.onclick = function(e) {        e.preventDefault()        bridge.callHandler('showChat', {qdId:'100005'}, function(response) {            console.log('JS got response', response)        })    }    // oc调用js方法    bridge.registerHandler('callJS', function(data, responseCallback) {        var responseData = { 'Javascript Says':'Right back atcha!' }        console.log('JS responding with', responseData)        responseCallback(responseData)    })})

参考：
https://github.com/marcuswestin/WebViewJavascriptBridge