如何檢查網絡可用性或檢查網絡並打開移動網絡？

作爲一個初學者，我試圖開發一個Android應用程序，它從服務器數據庫獲取數據。如何檢查網絡可用性或檢查網絡並打開移動網絡？

這裏，如果Wi-Fi目前還無法提供地方，我需要打開一個3G - 或2G - 數據，這是自動提供在Android設備上或者通過一個對話框打開移動網絡。

2014-07-15 user2885874

如何檢查無線互聯網連接：

ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); 
NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI); 

if (mWifi.isConnected()) { 
    // Do whatever 
}

添加權限清單中：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>

如何檢查是否針對移動互聯網連接（3G/LTE）：

boolean is3g = connManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE) 
      .isConnectedOrConnecting(); 

// Checks if Mobile network is available ... 

if(!is3g){ 

// IF MOBILE CONNECTION NOT AVAILBLE, OPEN SYSTEM SETTINGS FOR MOBILE NETWORKS 

    Intent intent = new Intent(); 
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
    intent.setAction(android.provider.Settings.ACTION_DATA_ROAMING_SETTINGS); 
    startActivity(intent); 

}

希望這會有所幫助，請將其標記爲接受的答案，如果它爲您工作。

來源

2014-07-15 09:13:13 Ayub

您可以檢查網絡是否可用，由該類

public class ConnectionDetector { 

private Context _context; 
public ConnectionDetector(Context context){ 
    this._context = context; 
} 

/** 
* Checking for all possible Internet providers 
* **/ 
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; 
}

}

檢查互聯網

ConnectionDetector conn = new ConnectionDetector(youractivity.this); 
    if(conn.isConnectingToInternet()){ 
     // call network operations 
    }else{ 
     // Toast 
    }

希望這可以幫助你

來源

2014-07-15 09:14:18

使用本代碼來檢查網絡的可用性： -

public class CheckConnection {

private Context _context;

public CheckConnection(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; 
}

}

來源

2014-07-15 09:14:22

試試這個：

findViewById(R.id.button).setOnClickListener(
         new OnClickListener() { 
          @Override 
          public void onClick(View v) { 
           // Check for n/w connection 
           if (!NetworkService 
             .isNetWorkAvailable(CurrentActivity.this)) { 
            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
              CurrentActivity.this); 
            // set title 
            alertDialogBuilder.setTitle("Warning"); 
            alertDialogBuilder 
              .setMessage("Check your network connection and try again."); 
            // set dialog message 
            alertDialogBuilder 
              .setCancelable(false) 
              .setNegativeButton(
                "Ok", 
                new DialogInterface.OnClickListener() { 
                 public void onClick(
                   DialogInterface dialog, 
                   int id) { 
                 } 
                }); 
            // create alert dialog 
            AlertDialog alertDialog = alertDialogBuilder.create(); 

            // show it 
            alertDialog.show(); 
           } else { 
           // Do your action if network exists 
            Intent i = new Intent(getApplicationContext(),NextActivity.class); 
            startActivity(i); 
           } 
          } 
         });

網絡服務。Java的：

import android.content.Context; 
import android.net.ConnectivityManager; 
import android.net.NetworkInfo; 

public final class NetworkService { 

    private NetworkService() {} 

    public static boolean isNetWorkAvailable(final Context contextActivity) { 
     ConnectivityManager conMgr = (ConnectivityManager) contextActivity.getSystemService(Context.CONNECTIVITY_SERVICE); 
     NetworkInfo activeNetwork = conMgr.getActiveNetworkInfo(); 
     return activeNetwork != null && activeNetwork.isConnected(); 
    } 
}

在清單中添加這些權限：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
<uses-permission android:name="android.permission.MODIFY_PHONE_STATE" />

來源

2014-07-15 09:14:27

findViewById ......真的嗎？ – Ayub

@Ayub是的，findViewById你有什麼疑問？ –

我認爲UI元素在這個問題上是無關緊要的，但是再一次，我可能是錯的 – Ayub

檢查網絡是否可用使用的代碼以下塊

private boolean isNetworkAvailable(Context mContext) { 
    // TODO Check network connection 
    ConnectivityManager connMgr = (ConnectivityManager) mContext 
      .getSystemService(Context.CONNECTIVITY_SERVICE); 
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo(); 
    if (networkInfo != null && networkInfo.isConnected()) 
     return true; 
    else 
     return false; 
}

和未來做以下的檢查條件如果WIFI不可用： -

private void setMobileDataEnabled(Context context, boolean enabled) { 
final ConnectivityManager conman = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); 
final Class conmanClass = Class.forName(conman.getClass().getName()); 
final Field iConnectivityManagerField = conmanClass.getDeclaredField("mService"); 
iConnectivityManagerField.setAccessible(true); 
final Object iConnectivityManager = iConnectivityManagerField.get(conman); 
final Class iConnectivityManagerClass = Class.forName(iConnectivityManager.getClass().getName()); 
final Method setMobileDataEnabledMethod = iConnectivityManagerClass.getDeclaredMethod("setMobileDataEnabled", Boolean.TYPE); 
setMobileDataEnabledMethod.setAccessible(true); 

setMobileDataEnabledMethod.invoke(iConnectivityManager, enabled);

} 你還需要這

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
<uses-permission android:name="android.permission.MODIFY_PHONE_STATE" />

來源

2014-07-15 09:25:11 Pravin

// Checking for all possible internet providers 
public boolean isConnectingToInternet(){ 

    ConnectivityManager connectivity = 
         (ConnectivityManager) 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; 
}

還指定這些權限：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
<uses-permission android:name="android.permission.MODIFY_PHONE_STATE" />

來源

2014-07-15 09:30:42 Andy

如何檢查網絡可用性或檢查網絡並打開移動網絡？

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