1.UIWebView js编码是window.prompt()
2.WKWebVIew js编码window.webkit.messageHandlers.(name).postMessage()
iOS13弃用UIWebView。换成WKWebVIew，js编码方法更改。之前用的JavaScriptCore (JSContext)已不能用，为了保证安卓端和H5端不更改项目源码，兼容老版本，采取了脚本转换的方法。

1.注入本地js脚本, 使js和native交互方法统一。

    NSString *jsSource = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"ios_brige" ofType:@"js"] encoding:NSUTF8StringEncoding error:nil];
    WKUserScript *script = [[WKUserScript alloc] initWithSource:jsSource injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:YES];
    [config.userContentController addUserScript:script];

2.WKScriptMessageHandler，JS回调统一处理。

// WKScriptMessageHandler
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message {
    NSLog(@"name:%@---body:%@",message.name,message.body);
    //用message.body获得JS传出的参数体
    NSString * parameter = message.body;
    NSData *jsonData = [parameter dataUsingEncoding:NSUTF8StringEncoding];
    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:nil];
    
    NSString *method = dic[@"method"];
    NSString *param = dic[@"params"];
    if (param) {
        method = [method stringByAppendingString:@":"];
    }
    SEL sel = NSSelectorFromString(method);
    if ([self respondsToSelector:sel]) {
        [self performSelectorOnMainThread:sel withObject:param waitUntilDone:YES];
    }else{
        NSLog(@"webview not find method %@",method);
    }
}

3.本地JS代码如下处理

function calliOSFunction(namespace, functionName, args, callback) {
    if (!window.webkit.messageHandlers[namespace]) return;
    var wrap = {
        "method": functionName,
        "params": args
    };
    window.webkit.messageHandlers[namespace].postMessage(JSON.stringify(wrap));
}

var jsCallNative = {};

//无返回值方法转换
//会将jsCallNative.toLogin()的调用方式，转换成window.webkit.messageHandlers.jsCallNative.postMessage()
jsCallNative.nativeClosePage = function () {
    calliOSFunction("ShowSnappedUpObj","nativeClosePage");
}
//有返回值方法转换
jsCallNative.nativeShowHud = function (infoStr) {
    calliOSFunction("ShowSnappedUpObj","nativeShowHud",infoStr);
}

//有返回值方法转换
//会将jsCallNative.getSign()的调用方式，转换成window.prompt()
jsCallNative.getSign = function () {
    var result = window.prompt("getSign");
    return result;
}

jsCallNative.appendABCwithString = function (str) {
    var result = window.prompt("appendABCwithString",str);
    return result;
}

jsCallNative.isLogin = function () {
    var result = window.prompt("isLogin");
    return result;
}

window["ShowSnappedUpObj"] = jsCallNative;