android - 在 HttpAsyncTask().execute() 中传递参数

Question

我的 android 应用程序使用 json 和 Http post 向 Web 服务器发布一个字符串，并使用了以下代码结构，但我想通过 HttpAsyncTask().execute("from here") 将几个参数传递给 AsyncTask<> 类。任何人都可以帮助我如何去做..你的帮助对我来说非常感谢提前感谢

btn_send.setOnClickListener(new OnClickListener(){
 @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            String strData = "Some String to post";
            String strURL = "http://My-Url/";   
            String reqTimeOut = "30000";  
            String Code = "9990001" ;
            String webRequest = SendWebRequest(strURL,strData, reqTimeOut, Code);// method to send HTTpPost request

        WriteToFile(webRequest);//writing response to file



private String SendWebRequest(String urlStr, String Data,String reqTimeOut, String Code)          

       {
            // TODO Auto-generated method stub

            String result="";
            try
            {
                /*

                           Some mandatory operations on Data
                 */


                   // Here i want to pass parameters: url, reqTimeout, Data, text and value(for setting header)  to POST method. 
                   new HttpAsyncTask().execute(urlStr);

            }catch(Exception e){}

            return result;
      }
public class HttpAsyncTask extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... params) {
        // TODO Auto-generated method stub
         return POST(params[0]);
    }

    // onPostExecute displays the results of the AsyncTask.
    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(getBaseContext(), "Data Sent!", Toast.LENGTH_LONG).show();
   }

    private String POST(final String url, final String postData,String text, String value) {
        // TODO Auto-generated method stub

        InputStream inputStream ;
        String result = "";


        try {



            // 1. create HttpClient
            HttpClient httpclient = new DefaultHttpClient();

            // 2. make POST request to the given URL
            HttpPost httpPost = new HttpPost(url);
            MainActivity.this.runOnUiThread(new Runnable() {
                  public void run() {
                      Toast.makeText(getApplicationContext(), "2. url is "+url,
                           Toast.LENGTH_LONG).show();
                  }
                });

            String json=postData ;         

         // 5. set json to StringEntity
            StringEntity se = new StringEntity(json);

            // 6. set httpPost Entity
            httpPost.setEntity(se);
          //  HttpConnectionParams.setConnectionTimeout(null, 300000);

            // 7. Set some headers to inform server about the type of the content   
           // httpPost.setHeader("Accept", "application/json");
            httpPost.setHeader(text, value);

            // 8. Execute POST request to the given URL
            HttpResponse httpResponse = httpclient.execute(httpPost);

            // 9. receive response as inputStream
            inputStream = httpResponse.getEntity().getContent();

            // 10. convert inputstream to string
            if(inputStream != null){
                result = convertInputStreamToString(inputStream);

            }
            else
                result = "Did not work!";

        } catch (Exception e) {


            Log.d("InputStream", e.getLocalizedMessage());
        }
     // 11. return result
        return result;
    }

Answer 1

为您的 HttpAsyncTask 类编写参数化构造函数。添加要在 HttpAsyncTask 类中使用的私有(private)字段。然后用所需的参数实例化 HttpAsyncTask 类对象。

你的类结构如下:

public class HttpAsyncTask extends AsyncTask<String, Void, String> {

    private String url,reqTimeout,data,text,value;
        public  HttpAsyncTask(String url,String reqTimeout,String data, String text, String value){
    this.url = url;
    this.reqTimeout = reqTimeout;
    this.data = data;
    this.text = text;
    this.value = value;
    }
        @Override
        protected String doInBackground(String... params) {
            // TODO Auto-generated method stub
             return POST(params[0]);
        }

        // onPostExecute displays the results of the AsyncTask.
        @Override
        protected void onPostExecute(String result) {
            Toast.makeText(getBaseContext(), "Data Sent!", Toast.LENGTH_LONG).show();
       }

        private String POST(final String url, final String postData,String text, String value) {
            // TODO Auto-generated method stub

            InputStream inputStream ;
            String result = "";


            try {



                // 1. create HttpClient
                HttpClient httpclient = new DefaultHttpClient();

                // 2. make POST request to the given URL
                HttpPost httpPost = new HttpPost(url);
                MainActivity.this.runOnUiThread(new Runnable() {
                      public void run() {
                          Toast.makeText(getApplicationContext(), "2. url is "+url,
                               Toast.LENGTH_LONG).show();
                      }
                    });

                String json=postData ;         

             // 5. set json to StringEntity
                StringEntity se = new StringEntity(json);

                // 6. set httpPost Entity
                httpPost.setEntity(se);
              //  HttpConnectionParams.setConnectionTimeout(null, 300000);

                // 7. Set some headers to inform server about the type of the content   
               // httpPost.setHeader("Accept", "application/json");
                httpPost.setHeader(text, value);

                // 8. Execute POST request to the given URL
                HttpResponse httpResponse = httpclient.execute(httpPost);

                // 9. receive response as inputStream
                inputStream = httpResponse.getEntity().getContent();

                // 10. convert inputstream to string
                if(inputStream != null){
                    result = convertInputStreamToString(inputStream);

                }
                else
                    result = "Did not work!";

            } catch (Exception e) {


                Log.d("InputStream", e.getLocalizedMessage());
            }
         // 11. return result
            return result;
        }

然后调用HttpAsyncTask类的execute方法时，调用方法如下:

HttpAsyncTask httpAsyncTask = new HttpAsyncTask(url,reqTimeout,data,text,value); httpAsyncTask().execute(urlStr);