Question

我的应用执行了一个HTTP请求，它将数据提交给php脚本，然后等待响应。当手机有互联网连接，但连接非常糟糕（即信号不良，或路由器没有连接到互联网）时，应用程序只需强制关闭。我怎么能阻止这个？

到目前为止，这些步骤是

人员按下提交按钮
这会启动一个异步任务，确保手机有连接（错误连接通过此）
执行HTTP Post
等待回复

所有这些步骤都围绕着try和catch来处理异常，但我仍然会强行关闭。

这是AsyncTask代码

private class checkDatabase extends AsyncTask<String, Void, Boolean> {

    ProgressDialog progressDialog;

    protected void onPreExecute() {
        super.onPreExecute();
        // Starting the progress dialog
        progressDialog = ProgressDialog.show(Login.this, "",
                "Connecting. Please wait...", true);

    }

    protected Boolean doInBackground(String... info) {
        // TODO Auto-generated method stub

        ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();

        if (netInfo != null && netInfo.isConnected()) {

            String us = info[0];
            String ps = info[1];

            String responseText;

            if (us.equals("") || ps.equals("")) {
                //No username or password
                return false;
            } else {
                try {
                    // Create a new HttpClient and Post Header
                    HttpClient httpclient = new DefaultHttpClient();
                    HttpPost httppost = new HttpPost(
                            "http://www.myfirstagent.com/android/loginquery.php");

                    // Add your data
                    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(
                            2);
                    nameValuePairs.add(new BasicNameValuePair("username",
                            us));
                    nameValuePairs.add(new BasicNameValuePair("password",
                            ps));
                    httppost.setEntity(new UrlEncodedFormEntity(
                            nameValuePairs));
                    HttpResponse response;
                    // Execute HTTP Post Request
                    try {
                        response = httpclient.execute(httppost);
                        responseText = EntityUtils.toString(response
                                .getEntity());
                    } catch (Exception e) {
                        //problem connecting
                        return false;

                    }

                    if (responseText.equals("accept")) {
                        return true;
                    } else if (responseText.equals("decline")) {
                        //invalid username or password
                        return false;

                    } else {
                        //something went wrong
                        return false;
                    }

                } catch (Exception e) {

                    //something went wrong
                    return false;
                }
            }

        } else {
            //No connection
            return false;
        }

    }

    protected void onPostExecute(Boolean result) {

        // Dismissing the progress dialog
        if (progressDialog.isShowing())
            progressDialog.dismiss();
        super.onPostExecute(result);
    }
}

Answer 1

检查响应是否为null。

如果你想抓住一切可能发生的事情，你可以抓住一个Throwable。

了解如何阅读堆栈跟踪，这是给您最好的建议。你必须了解你的程序失败的地方，以及他们如何有机会理解他们失败的原因并纠正它们。

等待互联网响应时强制关闭

1 个答案: