HttpUrlConnection android

Question

我是新的android开发人员.

我正在尝试使用此代码从我的网络服务器访问数据....

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    URL url;
    try {
        url = new URL("http://www.mysite.net/LEDstate.txt");

        HttpURLConnection urlConnection = (HttpURLConnection) url
                .openConnection();

        InputStream in = urlConnection.getInputStream();

        InputStreamReader isw = new InputStreamReader(in);

        int data = isw.read();
        while (data != -1) {
            char current = (char) data;
            data = isw.read();
            //System.out.print(current);


            TextView t = (TextView) findViewById(R.id.ledstate);

            t.setText(current); 
        }
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

}

但数据没有出现在屏幕上.Textview中没有任何变化.

我已经检查了权限他们没问题.

有帮助吗？谢谢.

Answer 1

我猜你得到了NetworkOnMainThreadException,但是因为你正在捕捉所有异常,所以错误被抑制了.

您无法在Ui线程上发出网络请求.将网络操作移至Asynctask.