从 Cordova 中的 java 方法调用 javascript 函数

Question

我为javascript和本地java代码之间的通信制作了一个插件。但由于某种原因，我不得不立即返回回调。反过来，我在java中启动了一个异步方法。现在完成实现后，我想回到我的javascript。请告诉我该怎么做。

我的java代码是-

public class MyPlugin extends CordovaPlugin
{
    String fileName;
    Context context;
    @Override
    public void initialize(CordovaInterface cordova, CordovaWebView webView) {
        super.initialize(cordova, webView);
        // your init code here
    }

     @Override
     public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException 
     {
            context=this.cordova.getActivity().getApplicationContext();
            String myurl = args.getString(0);
            if (action.equals("plugin1"))
            { 

                   new DownloadManager().execute(myurl);

                    callbackContext.success("Operation performed successfully!!");
                    return true;
             }


            callbackContext.error("error");
            return false;

     }

     public class DownloadManager extends AsyncTask<String, String, String> {

        @Override
        public String doInBackground(String... arg0) {
            downloadapk(arg0[0]);
            installapk();
            System.out.println("Download Complete");
            return null;
//Here I want to return to javascript.How can I callback to the javascript function from //async method?? 
        }

     }

Answer 1

您必须将callbackContext 传递给DownloadManager 类。

 @Override
 public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException 
 {
        context=this.cordova.getActivity().getApplicationContext();
        String myurl = args.getString(0);
        if (action.equals("plugin1"))
        {
            // Pass callbackContext to your actual code which performing the work.
            new DownloadManager(callbackContext).execute(myurl);
            return true;
        }

        callbackContext.error("error");
        return false;
 }

 public class DownloadManager extends AsyncTask<String, String, String> {
    private CallbackContext callbackContext;
    public DownloadManager(CallbackContext callbackContext) {
         this.callbackContext = callbackContext;
    }

    @Override
    public String doInBackground(String... arg0) {
        downloadapk(arg0[0]);
        installapk();
        this.callbackContext.success();
        return null;
        //Here I want to return to javascript.How can I callback to the javascript function from //async method?? 
    }