我想在填充列表视图之后检查互联网连接。但我检查互联网连接的代码不起作用。我断开我的网络连接测试但mycodes（检查连接不起作用）。 请帮我解决错误。
connectionDetector：
public class ConnectionDetector {
private Context _context;
public ConnectionDetector(Context context){
this._context = context;
}
public boolean isConnectingToInternet(){
ConnectivityManager connectivity = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null)
{
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
for (int i = 0; i < info.length; i++)
if (info[i].getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
return false;
}
}
我的活动：
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.updateapp);
oslist = new ArrayList<HashMap<String, String>>();
Btngetdata = (Button)findViewById(R.id.getdata);
Btngetdata.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//check Internet Connection
Boolean isInternetPresent = false;
ConnectionDetector cd;
cd = new ConnectionDetector(getApplicationContext());
isInternetPresent = cd.isConnectingToInternet();
if (isInternetPresent) {
new JSONParse().execute(); }
else {
// Internet connection is not present
// Ask user to connect to Internet
showAlertDialog(UpdateFromSite.this, "No Internet Connection",
"You don't have internet connection.", false);
}
}
});
}
public void showAlertDialog(Context context, String title, String message, Boolean status) {
AlertDialog alertDialog = new AlertDialog.Builder(context).create();
alertDialog.setTitle(title);
alertDialog.setMessage(message);
alertDialog.setIcon((status) ? R.drawable.success : R.drawable.fail);
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
}
});
alertDialog.show();
}
private class JSONParse extends AsyncTask<String, String, JSONObject> {
private ProgressDialog pDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
name = (TextView)findViewById(R.id.nameNewItem);
description = (TextView)findViewById(R.id.descriptionNewItem);
price = (TextView)findViewById(R.id.priceNewItem);
pDialog = new ProgressDialog(UpdateFromSite.this);
pDialog.setMessage("Getting Data ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected JSONObject doInBackground(String... args) {
JSONParser jParser = new JSONParser();
// Getting JSON from URL
JSONObject json = jParser.getJSONFromUrl(url);
return json;
}
@Override
protected void onPostExecute(JSONObject json) {
pDialog.dismiss();
try {
// Getting JSON Array from URL
android = json.getJSONArray(TAG_OS);
for(int i = 0; i < android.length(); i++){
JSONObject c = android.getJSONObject(i);
// Storing JSON item in a Variable
String name = c.getString(TAG_NAME);
String description = c.getString(TAG_DESCRIPTION);
String price = c.getString(TAG_PRICE);
// Adding value HashMap key => value
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_NAME, name);
map.put(TAG_DESCRIPTION, description);
map.put(TAG_PRICE, price);
oslist.add(map);
list=(ListView)findViewById(R.id.listupdate);
ListAdapter adapter = new SimpleAdapter(UpdateFromSite.this, oslist,
R.layout.updateapprow,
new String[] { TAG_NAME,TAG_DESCRIPTION, TAG_PRICE }, new int[] {
R.id.nameNewItem,R.id.descriptionNewItem, R.id.priceNewItem});
list.setAdapter(adapter);}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
的manifest.xml：
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
答案 0 :(得分：1)
使用以下方法检查网络连接：
public static boolean isNetworkAvailable(Context context) {
ConnectivityManager connectivityManager = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager
.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}
答案 1 :(得分：0)
public static void getNetworkState(Context context,OnConnectListener onConnectListener) {
final ConnectivityManager conMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
final NetworkInfo activeNetwork = conMgr.getActiveNetworkInfo();
if (activeNetwork != null && activeNetwork.isConnected()) {
//notify user you are online
onConnectListener.onConnect();
} else {
//notify user you are not online
onConnectListener.onDisConnect();
}
}
答案 2 :(得分：0)
使用此代码检查互联网连接
只需调用 checkInternetConnection（getBaseContext（））
/** Check network availability */
public static boolean checkInternetConnection(Context context) {
ConnectivityManager conMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo i = conMgr.getActiveNetworkInfo();
if (i == null)
return false;
if (!i.isConnected())
return false;
if (!i.isAvailable())
return false;
return true;
}
}
此代码经过测试！
答案 3 :(得分：0)
试试这个
public static boolean isNetworkConnection(Context context)
{
final ConnectivityManager connMgr = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connMgr.getActiveNetworkInfo();
if(activeNetworkInfo!= null && activeNetworkInfo.isAvailable() && activeNetworkInfo.isConnected())
return true;
else
return false;
}
答案 4 :(得分：0)
试试这个。
if(isNetworkConnected()){
// your task
} else {
Toast.makeText(getBaseContext(), "No internet connection available.",Toast.LENGTH_SHORT).show();
}
isNetworkConnected（）如下：
private boolean isNetworkConnected() {
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo ni = cm.getActiveNetworkInfo();
if (ni == null) {
// There are no active networks.
return false;
} else
return true;
}
答案 5 :(得分：0)
我一直在使用和工作的一个：
public class DetectConnection {
private Context _context;
public DetectConnection(Context context){
this._context = context;
}
public boolean isConnectedToInternet(){
ConnectivityManager connectivity = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null)
{
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
for (int i = 0; i < info.length; i++)
if (info[i].getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
return false;
}
}
：
DetectConnection dc = new DetectConnection(getApplicationContext());
if(dc.isConnectedToInternet()==true)
{
new AsyncGet().execute();
}
else
{
Toast.makeText(getSherlockActivity(), "No Active Connection", Toast.LENGTH_SHORT).show();
}
答案 6 :(得分：0)
试试这个..
public class ConnectionDetector {
private Context _context;
public ConnectionDetector(Context context){
this._context = context;
}
public boolean isConnectingToInternet(){
if( _context != null)
{
ConnectivityManager connec = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
try {
android.net.NetworkInfo wifi = connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
android.net.NetworkInfo mobile = connec.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if (wifi.isConnected()||mobile.isConnected())
return true;
else if (wifi.isConnected() && mobile.isConnected())
return true;
else
return false;
} catch (NullPointerException e) {
Log.d("ConStatus", "No Active Connection");
return false;
}
}
else
{
return false;
}
}
答案 7 :(得分：0)
试试这段代码。
public static boolean isConnectingToInternet(Context context) {
ConnectivityManager connectivity = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null) {
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
for (int i = 0; i < info.length; i++)
if (info[i].getState() == NetworkInfo.State.CONNECTED) {
return true;
}
}
return false;
}