在App中,會碰到使用webview,嵌入HTML,然手需要與JS互調的需求。
下面來說一下WebViewJavascriptBridge在ios端怎麼樣使用。
1.Objective-C初始化
UIWebView* webView = [[UIWebView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:webView];
2.將此webview與WebViewJavascriptBridge關聯(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)
})
});
這裏初始化先是創建了一個connectWebViewJavascriptBridge方法,該方法註冊了一個WebViewJavascriptBridgeReady事件,同時聲明瞭一個全局的WebViewJavascriptBridge變量。我們可以在外部通過WebViewJavascriptBridge調用相關方法。
在init裏面同樣有一個function,這個function同樣是用來接收Objective-C裏面通過send方法發送的消息的,參數與OC裏的send方法參數對應
4.Objective-C調用JavaScript
首先要在JavaScript裏面註冊一個方法:
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調用這個方法
[_bridge callHandler:@"showChat" data:data responseCallback:^(id response) {
NSLog(@"showChat responded: %@", response);
}];
5.JavaScript調用Objective-C
OC註冊一個方法:
[_bridge registerHandler:@"showChat" handler:^(id data, WVJBResponseCallback responseCallback) {
NSLog(@"showChat called: %@", data);
responseCallback(@"Response from showChat");
}];
JavaScript調用方法
bridge.callHandler('showChat', {'foo': 'bar'}, function(response) {
log('JS got response', response)
});
6.JavaScript向OC中發送消息
bridge.send(data, function(responseData) {
log('JS got response', responseData)
});
這種方式發送消息實際上是調用了OC初始化時的handle
7.OC向JavaScript發送消息
[_bridge send:@"A string sent from ObjC before Webview has loaded." responseCallback:^(id responseData) {
NSLog(@"objc got response! %@", responseData);
}];
這個send方法,實際上是調用了JavaScript初始化init裏面的function
附上我們應用中app.js的完整代碼
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發消息
bridge.send('Hello from the javascript')
bridge.send('response to xxx', function responseCallback(responseData) {
console.log("Javascript got its response", responseData)
})
// js調用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調用js方法
bridge.registerHandler('callJS', function(data, responseCallback) {
var responseData = { 'Javascript Says':'Right back atcha!' }
console.log('JS responding with', responseData)
responseCallback(responseData)
})
})