Question

在获取应用程序时遇到问题我正在构建以连接到Internet。我已经建立了能够检查有网络并且它是一个wifi网络，然后它尝试连接到Internet并从RSS源获取数据。

我在安装在BlackBerry PlayBook和BlackBerry Z10上的Android播放器上运行该应用程序。 PlayBook的行为符合预期，它可以很好地获得Feed。如果Z10设法清除错误检查，它会抛出异常，但如果没有可用的网络，它会按预期运行。

我应该提一下，该应用程序在其Manifest文件中具有相关权限，但由于某种原因，当我通过Android Studio的调试运行程序并且adb通过时，只有PlayBook打扰我显示权限屏幕编程到BlackBerry ADB Proxy Manager。在大约三次调试之后，它也只是为此而烦恼。

完全不知道我接下来应该尝试什么。有人有任何想法吗？

编辑：如果它有帮助，这是我在onCreate方法中从Android Studio添加到示例FullScreen Activity应用程序的代码：

ConnectivityManager cm =
            (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    Boolean isConnected = activeNetwork != null &&
            activeNetwork.isConnectedOrConnecting(); // Check for the existence of a network connection
    String helloString;
    if (isConnected == true) {
        // There is a network connection
        Log.i("helloHeadlines", "FullscreenActivity.onCreate - there is network available");
        //helloString = headlines_feed.connectionStatus();
        Boolean isWiFi = activeNetwork.getType() == ConnectivityManager.TYPE_WIFI ;
        if (isWiFi == true) {
            // There is WiFi - we may try to use the Internet
            headlines headlinesS = new headlines();
            try {
                helloString = headlinesS.headlines_stream()[0][0];
            } catch (Exception e) {
                helloString = "Error: Received an exception";
            }
            //helloString = "There is WiFi available";
        } else {
            helloString = "There is no WiFi available";
        }
    } else {
        // There is not a network connection
        helloString = "There is no network connection";
    }
    final TextView mTextView = (TextView) findViewById(R.id.fullscreen_content);
    mTextView.setText(helloString);

我认为问题不在于我的标题类，因为当我将它运行到控制台窗口时，它在PlayBook和Eclipse上运行良好。

编辑2：想想我可能找到了问题的根源。更改了一行代码并收到了一条新的错误消息：

} catch (Exception e) {
       helloString = "Error: Received an exception";
}

成了

} catch (Exception e) {
       helloString = e.toString();
}

给出了结果

android.os.NetworkOnMainThreadException

Answer 1

解决了它。去寻找异常，并在这个帖子中找到答案：networkonmainthread。不得不做一些重做，因为新线程没有正确地将其结果推入我的TextView。结束以下代码：

private String helloString;
private void setText() {
    final TextView mTextView = (TextView) findViewById(R.id.fullscreen_content);
    Log.i("helloHeadlines", "FullscreenActivity.onCreate - helloString equals " + helloString);
    mTextView.setText(helloString);
}

Thread thread = new Thread(new Runnable(){
    @Override
    public void run() {
        headlines headlinesS = new headlines();
        try {
            helloString = headlinesS.headlines_stream()[0][0];
            Log.i("helloHeadlines", "FullscreenActivity.thread.run - set helloString to " + helloString);
        } catch (Exception e) {
            helloString = e.toString();
            Log.i("helloHeadlines", "FullscreenActivity.thread.run - " + e.toString());
        }
        Log.i("helloHeadlines", "FullscreenActivity.thread.run - exiting try loop");
        setText();
    }
});

以及onCreate方法中的以下内容：

ConnectivityManager cm =
        (ConnectivityManager)     getSystemService(Context.CONNECTIVITY_SERVICE);

NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
Boolean isConnected = activeNetwork != null &&
        activeNetwork.isConnectedOrConnecting(); // Check for the existence of a network connection

if (isConnected == true) {
    // There is a network connection
    Log.i("helloHeadlines", "FullscreenActivity.onCreate - there is network available");
    //helloString = headlines_feed.connectionStatus();
    Boolean isWiFi = activeNetwork.getType() == ConnectivityManager.TYPE_WIFI ;
    if (isWiFi == true) {
        // There is WiFi - we may try to use the Internet
        thread.start();
        Log.i("helloHeadlines", "FullscreenActivity.onCreate - exited thread.");
        //helloString = "There is WiFi available";
    } else {
        helloString = "There is no WiFi available";
    }
} else {
    // There is not a network connection
    helloString = "There is no network connection";
}
setText();

坚持从在BlackBerry 10.3上运行的Android应用程序访问互联网

1 个答案: