Question

我遇到了问题。

我正在努力解决这个问题，因为没有结果：

    public void getData(){

    new Task().execute();


}

class Task extends AsyncTask<Void, Void, String>{

    @Override
    protected String doInBackground(Void... noargs) {
        return null;
    }

    protected void onPostExecute(String result){

        DefaultHttpClient client = new DefaultHttpClient();
        HttpGet request = new HttpGet("http://www.omdbapi.com/?t=True%20Grit&y=1969");
        try {
            HttpResponse response = client.execute(request);
            BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            String line = "";
            StringBuffer zeile = new StringBuffer("");

            while((line = rd.readLine()) != null){
                zeile.append(line);
            }

            String res = zeile.toString();

            Toast toast = Toast.makeText(getApplicationContext(), res, Toast.LENGTH_SHORT);
            toast.show();
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

每次（按钮调用getDate（））我得到一个例外，在我的手机上它说“不幸的是应用程序已经完成”。你知道我的错误在哪里吗？

异常是：NetworkOnMainThreadException，我该如何解决？

非常感谢你！

Answer 1

您应将所有与网络相关的代码移至doInBackground()，并在onPostExecute()内处理网络调用的结果。以下是您的代码的外观：

class Task extends AsyncTask<Void, Void, String>{

    @Override
    protected String doInBackground(Void... noargs) {
        DefaultHttpClient client = new DefaultHttpClient();
        HttpGet request = new HttpGet("http://www.omdbapi.com/?t=True%20Grit&y=1969");
        try {
            HttpResponse response = client.execute(request);
            BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            String line = "";
            StringBuffer zeile = new StringBuffer("");

            while((line = rd.readLine()) != null){
                zeile.append(line);
            }

            String res = zeile.toString();
            return res;  
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "";
    }

    protected void onPostExecute(String result){
            Toast toast = Toast.makeText(getApplicationContext(), result, Toast.LENGTH_SHORT);
            toast.show();
    }

}

Answer 2

在UI线程上运行异步任务的

onPostExecute()和onPreExecute()。将网络代码从onPostExecute()移至doInBackground()。

如何从Android中的AsyncTask实现Web服务连接？

2 个答案: