如何运行多个 URL 连接？

Question

我想使用 Android Native 运行两个连接：

 public class MyPublicClass extends AppCompatActivity {

这是第一堂课

private class GetNextQuestionIndex extends AsyncTask<String, Void, Void> {
    //some code
    protected Void doInBackground(String... params) {
    URL url = new URL("url1");
    //some code to initialize connection and get the output

    MyPublicClass.this.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        mytxtview.setText(output1)
                        System.out.println("1");
                        progress.dismiss();
                    }
                });

这是第二课

private class GetLibelleOfQuestion extends AsyncTask<String, Void, Void> {
    //some code
    protected Void doInBackground(String... params) {
    URL url = new URL("url2");
    //some code to initialize another connection and get another output

    MyPublicClass.this.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        mytxtview.setText(output2)
                        System.out.println("2");
                        progress.dismiss();
                    }
                });
}//the end of the public class

但是当我运行我的代码时它给了我

2 1

我怎样才能得到

1 2

？ 这意味着在运行GetLibelleOfQuestion之前执行GetNextQuestionIndex的运行

Answer 1

onCreateActivity(...){
    ...
    ShowDialog();
    AsyncTask1(...).execute();
}

public void callAsyncTask2(){
        AsyncTask2(...).execute();
}

class AsyncTask1(...){
    ....
    onPostExecute(...){
    activity.callAsyncTask2();
    }
}

class AsyncTask2(...){
    ....
    onPostExecute(...){
    activity.dismissDialog();
    }
}

希望对你有帮助。

Answer 2

这是调用 2 asyn task 的正确方法。

    private class GetNextQuestionIndex extends AsyncTask<String, Void, String> {

                @Override
                protected String doInBackground(String... params) {
                     URL url = new URL("url2");
                   //run your background task
                    return results;
                }

                @Override
                protected void onPostExecute(String result) {
                      mytxtview.setText(output1)
                            System.out.println("1");
                              new GetLibelleOfQuestion ().execute("");
                }

                @Override
                protected void onPreExecute() {
                progress.dismiss();
                }

                @Override
                protected void onProgressUpdate(Void... values) {}
            }
        }

//Second asyn task

      private class GetLibelleOfQuestion extends AsyncTask<String, Void, String> {

                @Override
                protected String doInBackground(String... params) {
                     URL url = new URL("url2");
                   //run your background task
                    return results;
                }

                @Override
                protected void onPostExecute(String result) {
                      mytxtview.setText(output2)
                            System.out.println("2");
                            progress.dismiss();
                }

                @Override
                protected void onPreExecute() {}

                @Override
                protected void onProgressUpdate(Void... values) {}
            }
        }

oncreate 方法调用或按钮点击，你想要的地方

new GetNextQuestionIndex ().execute("");

Answer 3

您可以使用设置第二个线程休眠片刻（等待第一个线程执行）：

private class GetLibelleOfQuestion extends AsyncTask<String, Void, Void> {
...
    MyPublicClass.this.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Thread.sleep(WAIT_TIME_IN_MILLISECONDS);
                        mytxtview.setText(output2)
                        System.out.println("2");
                        progress.dismiss();
                    }
                });
}//the end of the public class