Question

我有这个代码，我有2个AsyncTask，我通过按钮调用它，我还有一个我想问的是，当打开活动时有没有办法自动调用Asynctask？

我尝试使用onCreate，但它是错误

public class SingleCompleteOrder extends ActionBarActivity {


    private static final String comp_id = "complete_id";
    private static final String comp_table = "complete_table";
    private static final String comp_items = "complete_items";
    private static final String comp_date = "complete_date";

    private TextView oid;


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // TODO Auto-generated method stub

        return true;
    }


    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // TODO Auto-generated method stub

        switch (item.getItemId()) {


            case android.R.id.home:

                onBackPressed();

                break;

            default:
                break;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_single_contact);    




        ...
        ...
        ...
        ...
        ...
    }

public void huss() {
            Updatsituation task = new Updatsituation ();
            task.execute();


}
private class Updatsituation extends AsyncTask<Void,Void,Boolean>  {
        private ProgressDialog pd;
        private Boolean result = false;


        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub
            super.onPreExecute();

            pd = new ProgressDialog(SingleCompleteOrder.this);
            pd.setMessage("Processing commend,Please wait");
            pd.setProgressStyle(ProgressDialog.STYLE_SPINNER);
            pd.setCancelable(false);
            pd.show();
        }

        @Override
        protected Boolean doInBackground(Void... params) {
            // TODO Auto-generated method stub

            HttpClient client = new DefaultHttpClient();
            HttpPost post = new HttpPost(Utils.WS_UPDATE_SITUAT);

            List<NameValuePair> mParams = new ArrayList<NameValuePair>();

            mParams.add(new BasicNameValuePair("complete_id", oid.getText().toString()));
            mParams.add(new BasicNameValuePair("order_situation","showed"));

            try {

                post.setEntity(new UrlEncodedFormEntity(mParams));

                HttpResponse response = client.execute(post);

                String res = EntityUtils.toString(response.getEntity());

                Log.d("Order Preview", res);

                JSONObject jsonObj = new JSONObject(res);

                result = jsonObj.getBoolean("Result");


            } catch (ClientProtocolException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            return result;
        }

        @Override
        protected void onPostExecute(Boolean res) {
            // TODO Auto-generated method stub
            super.onPostExecute(res);

            if (pd != null)
                pd.dismiss();

            if (res) {

                Toast.makeText(SingleCompleteOrder.this,
                        "Order Completed Successfully", Toast.LENGTH_SHORT)
                        .show();

                finish();

                Intent intent = new Intent(SingleCompleteOrder.this,
                        CompleteOrdertest.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(intent);

            } else {

                Toast.makeText(SingleCompleteOrder.this,
                        "Unable to process the command", Toast.LENGTH_SHORT)
                        .show();
            }
        }

    }

}

Answer 1

如果要在创建活动时运行Async任务，可以使用OnCreate方法执行此操作。或者如果您希望每次活动变为可见时执行此操作，您都可以在onResume方法中运行它。

我没有看到您在任何OnCreate或OnResume方法中调用huss（）方法。

编辑：试试这个：

@Override
protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_single_contact);    
        huss();



        ...
        ...
        ...
        ...
        ...
    }

Answer 2

如果要调用AsyncTask，只需在Activity的onCreate（）方法中执行以下操作：

@Override public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // All lines of code
    new Updatsituation().execute(); 
}

这样就可以启动任务，而无需点击任何按钮。

你可以把它放在onResume（）中，但是每次你的活动恢复时都要准备好它。

Answer 3

如果要自动调用AsyncTask，则需要在OnCreate（）方法上调用它。

@Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        new Updatsituation().execute(); //call your async task

}

自动调用AsyncTask

3 个答案: