android - 在 Android 上下载 html 源会使应用程序崩溃

Question

我正在尝试将某些网站的代码下载到我的应用程序中，如下所示:

 public void wypned(final View pwn) throws IllegalStateException, IOException{
    HttpClient httpClient = new DefaultHttpClient();
    HttpContext localContext = new BasicHttpContext();
    HttpGet httpGet = new HttpGet("http://example.com");
    HttpResponse response = httpClient.execute(httpGet, localContext);
    String result = "";

    BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent() ) );

    String line = null;
    while ((line = reader.readLine()) != null){
    result += line + "\n";
    }
}

我得到的只是 fatal error 。 LogCat 说:

Caused by: android.os.NetworkOnMainThreadException
 on Android 3.x and up, you can't do network I/O on the main thread

有人能告诉我怎么解决吗？我尝试用线程做一些事情，但没有成功。

Answer 1

为此实现一个 asyncTask :

public class MyAsyncTask extends AsyncTask<Void, Void, Result>{

                        private Activity activity;
                        private ProgressDialog progressDialog;

            public MyAsyncTask(Activity activity) {
                            super();
                this.activity = activity;
            }

            @Override
            protected void onPreExecute() {
            super.onPreExecute();
                progressDialog = ProgressDialog.show(activity, "Loading", "Loading", true);
            }

            @Override
            protected Result doInBackground(Void... v) {
            //do your stuff here
            return null;

            }

            @Override
            protected void onPostExecute(Result result) {
                progressDialog.dismiss();
                Toast.makeText(activity.getApplicationContext(), "Finished.", 
                        Toast.LENGTH_LONG).show();
            }


}

从 Activity 中调用它:

MyAsyncTask task = new AsyncTask(myActivity.this);
task.execute();