我正在開發(fā)一個 Android 應(yīng)用程序，它可以識別設(shè)備是否連接到網(wǎng)絡(luò)。如果沒有，應(yīng)用程序會顯示AlertDialog并讓用戶有機(jī)會轉(zhuǎn)到設(shè)備設(shè)置并打開 wifi。我已經(jīng)為這項工作創(chuàng)建了一個BroadcastReceiver，但我不知道如何創(chuàng)建一個AlertDialog并為用戶提供啟用 wifi 的選項。這是 的代碼BroadcastReceiver。public class ExampleBroadcastReceiver extends BroadcastReceiver {@Overridepublic void onReceive(final Context context, Intent intent) { if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())) { boolean noConnectivity = intent.getBooleanExtra( ConnectivityManager.EXTRA_NO_CONNECTIVITY, false ); if (noConnectivity) { AlertDialog.Builder builder1 = new AlertDialog.Builder(context); builder1.setMessage("You must have internet connection"); builder1.setCancelable(true); builder1.setPositiveButton( "Yes", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { } }); builder1.setNegativeButton( "No", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { dialog.cancel(); } }); builder1.create(); builder1.show(); } else { Toast.makeText(context, "Connected", Toast.LENGTH_SHORT).show(); } }}}
1 回答
溫溫醬
TA貢獻(xiàn)1752條經(jīng)驗 獲得超4個贊
請注意，以下代碼僅供您參考。您可以根據(jù)您的要求更新/更改此代碼。
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private BroadcastReceiver mNetworkReceiver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
registerNetworkBroadcastForNougat();
}
private void registerNetworkBroadcastForNougat() {
mNetworkReceiver = new NetworkChangeReceiver();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
registerReceiver(mNetworkReceiver, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
registerReceiver(mNetworkReceiver, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
}
}
protected void unregisterNetworkChanges() {
try {
unregisterReceiver(mNetworkReceiver);
} catch (IllegalArgumentException e) {
e.printStackTrace();
}
}
@Override
public void onDestroy() {
super.onDestroy();
unregisterNetworkChanges();
}
class NetworkChangeReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent)
{
try
{
if (!isOnline(context)) {
showDialog(context);
}
} catch (NullPointerException e) {
e.printStackTrace();
}
}
private void showDialog(final Context context) {
AlertDialog.Builder builder1 = new AlertDialog.Builder(context);
builder1.setMessage("You must have internet connection");
builder1.setCancelable(true);
builder1.setPositiveButton(
"Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
startActivity(new Intent(WifiManager.ACTION_PICK_WIFI_NETWORK));
}
});
builder1.setNegativeButton(
"No",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
builder1.create();
builder1.show();
}
private boolean isOnline(Context context) {
try {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
//should check null because in airplane mode it will be null
return (netInfo != null && netInfo.isConnected());
} catch (NullPointerException e) {
e.printStackTrace();
return false;
}
}
}
}
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