iOS WKWebView与JS交互

1.OC调用JS方法

    NSString *shareMethod = @"share('参数1')";
    [self.webView evaluateJavaScript:shareMethod completionHandler:^(id _Nullable objStr, NSError * _Nullable error) {
    }];

2.JS调用OC的方法

1.初始化WKWebView时，调用addScriptMessageHandler:name:方法，name为js中的方法名

  - (void)setupWKWebView {
    //cookie
    WKCookieSyncManager *manager = [WKCookieSyncManager sharedWKCookieSyncManager];
    cookieStr = [manager setCookieWithIsCustomMsg:_chatCustomMsgBool];
    WKUserScript *cookieScript = [[WKUserScript alloc] initWithSource:cookieStr injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:NO];
    //初始化WKWebViewConfiguration
    WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init];
    //方法集合
    ocAndJSMethodArr = [Helper jsCallOCMethodArr];
    //初始化WKUserContentController
    userContentController = [[WKUserContentController alloc] init];
    for (NSString *methodStr in ocAndJSMethodArr) {//注册供js调用的方法
        [userContentController addScriptMessageHandler:self name:methodStr];
    }
    configuration.preferences.javaScriptCanOpenWindowsAutomatically = YES;
    [userContentController addUserScript:cookieScript];
    configuration.userContentController = userContentController;
    configuration.preferences.javaScriptEnabled = YES;
 //初始化WKWebView
    _webView = [[WKWebView alloc] initWithFrame:self.view.bounds) configuration:configuration]; 
    _webView.navigationDelegate = self;
    _webView.UIDelegate = self;
    [self.view addSubview:_webView];
    
    _mutRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:_urlStr] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:15];
    //设置cookie
    NSDictionary *cookiesDcit = [CustomeSetWebViewCookie setWebViewCookieWithURL:_urlStr isCustomMsg:NO];
    [_mutRequest setValue: [cookiesDcit objectForKey:@"Cookie"] forHTTPHeaderField: @"Cookie"];

h5:类似如下代码

window.webkit.messageHandlers.share.postMessage()

2.实现WKScriptMessageHandler代理方法，当js调用scan方法时，会回调此代理方法：

//加载页面数据完成
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation {
    DLog(@"加载页面完成"); 
    NSMutableString *mutMethodStr = [[NSMutableString alloc] init];
    //由于h5那边没有按照类似于“window.webkit.messageHandlers.share.postMessage() ”的语法处理，以及为了JS通过类似于“Test_APP”的对象调用OC方法，所以通过注入一段以下这样的JS代码给网页以便本地调用
    for (int i=0; i<ocAndJSMethodArr.count; i++) {
        if (i<ocAndJSMethodArr.count-1) {
            [mutMethodStr appendFormat:@"\"%@\",",ocAndJSMethodArr[i]];
        } else {
            [mutMethodStr appendFormat:@"\"%@\"",ocAndJSMethodArr[i]];
        }
    }
    NSString *promptCode = [NSString stringWithFormat:@"(function(appName, methods){window[appName] = {};methods.forEach(function(v){window[appName][v] = function(a){window.webkit.messageHandlers[v].postMessage(a);}});})(\"%@\",[%@]);console.info(Test_APP);",JSAndOCObject,mutMethodStr];
    [_webView evaluateJavaScript:promptCode completionHandler:nil];
//这段是为了处理弹框
/*
NSDictionary *dict = @{@"AlertVal":@"0",@"functionName":functionName};
                NSString *jsStr = [NSString stringWithFormat:@"iosCallBack('getAlertVal','%@')",[Helper dictionaryToJson:dict]];
                jsStr = [jsStr stringByReplacingOccurrencesOfString: @"\r" withString:@""];
                jsStr = [jsStr stringByReplacingOccurrencesOfString: @"\n" withString:@""];
                dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                    [jsContext evaluateScript:jsStr];
                });
*/
    NSString *functionCallStr = [NSString stringWithFormat:@"function iosCallBack (functionName, arg){window[functionName](arg);}"];
    [_webView evaluateJavaScript:functionCallStr completionHandler:nil];
}

#pragma mark - WKScriptMessageHandler
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message {
//    if ([message.name isEqualToString:@"share"]) {
//        //调用原生分享
//    }
    if(message.name ==nil || [message.name isEqualToString:@""])
        return;
    //message.body 传过来值
    //message.name  js发送的方法名称
    [self.jsNativeMethod nativeDidReceiveScriptMessageName:message.name messageBody:message.body];
}
- (JSNativeMethod *)jsNativeMethod {
    if (!_jsNativeMethod) {
        _jsNativeMethod = [[JSNativeMethod alloc] init];
    }
    return _jsNativeMethod;
}

注：页面销毁时，需要移除掉所调用的方法

- (void)removeScriptMessage {
    //注册的方法要在view dealloc前 remove 否则 不走 dealloc,会循环引用
    for (NSString *nameStr in ocAndJSMethodArr) {
        [userContentController removeScriptMessageHandlerForName:nameStr];
    }
}