Javascript之JSBridge初探

public class CustomWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
      ......
      // 场景一： 拦截请求、接收 scheme
        if (url.equals("xxx")) {

            // handle
            ...
            // callback
            view.loadUrl("javascript:setAllContent(" + JSON + ");")
            return true;
        }
        return super.shouldOverrideUrlLoading(url);
     }
}

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{
    if ([navigationAction.request.URL.absoluteString hasPrefix:@"xxx"]) {
        [[UIApplication sharedApplication] openURL:navigationAction.request.URL];
    }
    decisionHandler(WKNavigationActionPolicyAllow);
}

public boolean onJsPrompt(WebView view, String origin, String message, String defaultValue, final JsPromptResult result) {
  String handledRet = parentEngine.bridge.promptOnJsPrompt(origin, message,defaultValue);
  xxx;
  return true;
}

-(void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler{

  UIAlertController *alertController = [UIAlertController                    alertControllerWithTitle:nil message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];

  [alertController addAction:([UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

      completionHandler();

  }])];

  [self presentViewController:alertController animated:YES completion:nil];

}

alert("确定xxx?", "取消", "确定", callback());

gpcWebView.addJavascriptInterface(new JavaScriptInterface(), 'nativeApiBridge'); 
public class JavaScriptInterface {
    Context mContext;

  JavaScriptInterface(Context c) {
    mContext = c;
  }

  public void share(String webMessage){            
    // Native 逻辑
  }
}

window.NativeApi.share(xxx);

WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init];
WKPreferences *preferences = [WKPreferences new];
preferences.javaScriptCanOpenwindowsAutomatically = YES;
preferences.minimumFontSize = 40.0;
configuration.preferences = preferences;
    

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self.webView.configuration.userContentController addScriptMessageHandler:self name:@"share"];
      [self.webView.configuration.userContentController addScriptMessageHandler:self name:@"pickImage"];
}
- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [self.webView.configuration.userContentController     removeScriptMessageHandlerForName:@"share"];
    [self.webView.configuration.userContentController removeScriptMessageHandlerForName:@"pickImage"];
}

window.webkit.messageHandlers.share.postMessage(xxx);

webView.loadUrl("javascript:" + javaScriptString);
webView.evaluateJavascript(javaScriptString, new ValueCallback<String>() {
  @Override
  public void onReceiveValue(String value){
    xxx
  }
});

// swift
func evaluateJavaScript(_ javaScriptString: String, 
    completionHandler: ((Any?, Error?) -> Void)? = nil)
// javaScriptString 需要调用的 JS 代码
// completionHandler 执行后的回调
// objective-c
[jsContext evaluateJavaScript:@"ZcyJsBridge(ev, data)"]

params = {
  api_version: "xxx",    // API 版本
  title: "xxx",    // 标题
  filename: "xxx",    // 文件名称
  image: "xxx",    // 图片链接
  url: "xxx",    // 网址链接
  success: function (res) {
    xxx;    // 调用成功后执行
  },
  fail: function (err) {
    if (err.code == '-2') {
      fail && fail(err);    //    调用了当前客户端中不存在的 API 版本
    } else {
      const msg = err.msg;    //异常信息
      Toast.fail(msg);
    }
  }
};
window.NativeApi.share(params);

window.NativeApi.xxx({
    api_version:'',
    name: "xxx",
    path: "xxx",
    id:    "xxx",
    success: function (res) {
      console.log(res);
    },
    fail: function (err) {
      console.log(err);
    }
});

reqNativeBridge(vm, fn) {
  if (!isApp()) {
    // 如果不在 APP 内进行调用
    vm.$dialog.alert({
      message: "此功能需要访问 APP 才能使用",
    });
  } else {
    if (!window.NativeApi) {
      // 针对初期版本
      vm.$dialog.alert({
        message: "请更新到最新 APP 使用该功能",
      });
    } else {
      // 此处只针对“调用了当前客户端中不存在的 API 版本”的报错进行处理
      // 其余种类的错误信息交由具体的业务去处理
      fn && fn((err) => {
        vm.$dialog.alert({
          message: "请更新到最新 APP 使用该功能",
        });
      });
    }
  }
}