无法从onPostExecute调用方法

Question

我正在使用异步任务来运行JSON下载器:(删节)

public class JSONDownloader extends AsyncTask<Object, Object, Object>{
    @Override
    protected Object doInBackground(Object... params) {
        if(JSONstate == false){
            try {
                final URL url = new URL([REDACTED]);

                final URLConnection urlConnection = url.openConnection();
                urlConnection.setRequestProperty("Content-Type", "application/json; charset=utf-8");
                urlConnection.connect();
                final InputStream inputStream = urlConnection.getInputStream();
                final StringBuilder sb = new StringBuilder();
                while (inputStream.available() > 0) {
                    sb.append((char) inputStream.read());
                }
                String result = sb.toString();

                JSONObject jsonOrg = new JSONObject(result);

                String ok = "ok";

                Response = jsonOrg.getString("response");
                System.out.println(Response);

                if(Response.equals(ok)){
                    Settingsresponse = true;

                    orgName = jsonOrg.getString("orgName");
                    System.out.println("orgName" + orgName);
                    accessPointName = jsonOrg.getString("attendanceRecorderName");
                    System.out.println("accessPointName" + accessPointName);
                    lat = jsonOrg.getString("latitude");
                    System.out.println("lat" + lat);
                    longi = jsonOrg.getString("longitude");
                    System.out.println("longi" + longi);
                    floor = jsonOrg.getString("floor");
                    System.out.println("floor" + floor);
                    orgId = jsonOrg.getString("orgId");
                    System.out.println("orgId" + orgId);
                }
                else{
                    System.out.println("Data sent was erroneous");
                    Settingsresponse = false;
                }
            } catch (Exception e) {
                System.err.print(e);      
            }
        }
        else if(JSONstate == true){
            try {                   
                                    [redacted]
                }
                else{
                    System.out.println("Data sent was erroneous");
                    Settingsresponse = false;
                }
            } catch (Exception e) {
                System.err.print(e);      
            }
        }
        return null;
    }
    protected void onPostExecute(Void result){
        if(JSONstate == false){
            System.out.println("This piece of code is definitely being run");
            setfields();
        }
        else if(JSONstate == true){
            settestfields();
        //This method does not run upon the completion of the JSON request, as it supposedly should
                    }
    }
}

完成JSONRequest后,'onPostExecute'方法不会运行.我一直在尝试使用此方法,以便在请求完成后立即更新一组字段,而不必设置明确的等待时间.我只是简单地利用代码错了吗？还是有什么我错过的？

Answer 1

您没有覆盖onPostExecute的正确方法.

你有:

protected void onPostExecute(Void result)

你需要:

protected void onPostExecute(Object result)

请注意,您提供的第三个通用参数是类型Object.这是onPostExecute用作参数的类型.所以,方法签名onPostExecute需要接受一个Object,而不是Void.

你应该在这里使用boolean的结果类型而不是object,并删除Json状态类变量.这使您的AsyncTask更加灵活,并且可以允许您在执行后向用户显示操作完成的一些指示.