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我正在开发 android 应用程序并从 php webservice 获取数据。在调用 php webservice 之前，我正在检查互联网连接。如果存在连接，则只有异步任务将启动。但是在这里我遇到了另一个问题，即在检查互联网连接后并在以异步方法执行后台任务时，有时电源突然断电，此时崩溃即将来临。但实际上，如果未执行 try 操作，我使用了一个布尔变量并保持 server=false 。但是，当将参数发布到 php 时没有互联网连接时，它不会捕获方法，因此它不会将 toast 消息显示为“再试一次”。请告诉我实际上我哪里出错了。

My code:

boolean server = true;
@Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.test);

if (haveNetworkConnection()) {
                    LongOperation1 op = new LongOperation1();
                    op.execute("");
                } else {
                    Toast.makeText(getApplicationContext(),
                            "No Network Connection", Toast.LENGTH_LONG).show();
                }
}


private void loadFeed()

    {

        ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
        postParameters.add(new BasicNameValuePair("val1",value1));
        postParameters.add(new BasicNameValuePair("val2",value2));


        try {
            response = CustomHttpClient
                    .executeHttpPost(
                            "http://....................../file.php",
                            postParameters);
            System.out.println("the ultimate response" + response);
        }

        catch (Exception e) {

            server = false;
            e.printStackTrace();
        }

    }

    private boolean haveNetworkConnection() {
        boolean haveConnectedWifi = false;
        boolean haveConnectedMobile = false;

        ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo[] netInfo = cm.getAllNetworkInfo();
        for (NetworkInfo ni : netInfo) {
            if (ni.getTypeName().equalsIgnoreCase("WIFI"))
                if (ni.isConnected())
                    haveConnectedWifi = true;
            if (ni.getTypeName().equalsIgnoreCase("MOBILE"))
                if (ni.isConnected())
                    haveConnectedMobile = true;
        }
        return haveConnectedWifi || haveConnectedMobile;
    }

    private class LongOperation1 extends AsyncTask<String, Void, String> {

        @Override
        protected String doInBackground(String... params) {

            loadFeed();
            return "Executed";
        }

        @Override
        protected void onPostExecute(String result) {
            dialog1.dismiss();
            try {

                if (server) {


                        Toast.makeText(getApplicationContext(),
                            "Success", Toast.LENGTH_LONG).show();




                } else {
                    Toast.makeText(getApplicationContext(),
                            "Try Again", Toast.LENGTH_LONG).show();

                }
            }

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

        }

        @Override
        protected void onPreExecute() {
            dialog1 = ProgressDialog.show(Reuse.this, "Please wait...",
                    "Retrieving data ...", true);
        }

        @Override
        protected void onProgressUpdate(Void... values) {
        }
    }
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