在android上检查互联网连接

时间：2010-11-03 10:37:00

标签： android connection

我有以下代码用于检查我的应用程序上的互联网连接wifi / EDGE / GPRS / 3G。

代码是

public static boolean checkConn(Context ctx) {
    ConnectivityManager conMgr = (ConnectivityManager) ctx
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    if (conMgr.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED
        || conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTING) {
        return true;
    } else if (conMgr.getNetworkInfo(0).getState()==NetworkInfo.State.DISCONNECTED
        || conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.DISCONNECTED){
        return false;
    }
    return false;
}

我打电话给它如下：

if (CheckInternet.checkConn(introPage.this) == true) {
    Intent toMainPage = new Intent(introPage.this, mainPage.class);
    System.gc();
    startActivity(toMainPage);
} else if (CheckInternet.checkConn(getApplicationContext()) == false) {
    Toast.makeText(getApplicationContext(),
        "Sorry, No internet connectivity found", Toast.LENGTH_SHORT)
            .show();
}

但是我遇到了一个问题，即如果我连接到wifi，我打开应用程序，它工作正常，但如果我关闭应用程序并关闭wifi并重新打开应用程序，它不会通过“无连接”的错误，我需要关闭我的设备，然后打开它，同样的情况是如果wifi关闭，我打开应用程序，它会抛出“无连接”的错误，如果我打开它，除非我关闭并打开设备，否则它会抛出相同的“无连接”错误。

10 个答案:

答案 0 :(得分：68)

有时，活动连接不在列表中的第一位，或者处于非活动状态或处于错误状态。我就是这样做的：

  NetworkInfo i = conMgr.getActiveNetworkInfo();
  if (i == null)
    return false;
  if (!i.isConnected())
    return false;
  if (!i.isAvailable())
    return false;
  return true;

[编辑1]不要忘记在应用程序清单中添加此权限：

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

这对你有帮助吗？

灵光

答案 1 :(得分：3)

答案简短：

public boolean isNetworkAvailable() {
    ConnectivityManager connectivityManager = (ConnectivityManager)getActivity().getApplicationContext()
                                              .getSystemService(Context.CONNECTIVITY_SERVICE);

    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
    return activeNetworkInfo != null;
}

答案 2 :(得分：2)

更好：

if (conMgr != null) {
    NetworkInfo i = conMgr.getActiveNetworkInfo();
    if (i != null) {
        if (!i.isConnected())
            ret = false;
        if (!i.isAvailable())
            ret = false;                
    }

    if (i == null)
        ret = false;

} else
    ret = false;

使用另一种形式，如果“Network i”等于null，则检查!i.isConnected()必须失败（i为空）。

答案 3 :(得分：2)

public static boolean checkNetworkStatus(Context context) {
    ConnectivityManager connectivity = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    TelephonyManager telephony = (TelephonyManager) context
            .getSystemService(Context.TELEPHONY_SERVICE);
    NetworkStatus netStatus = new NetworkStatus(connectivity, telephony);
    if (netStatus.isNetworkAvailable() == true) {
        Log.e(" in checkNetworkStatus()", "network available");
        return true;
    } else {
        Log.e(" in checkNetworkStatus()", "no network");
        return false;
    }
}

无线网络 - 

void chkStatus() {
    final ConnectivityManager connMgr = (ConnectivityManager) this
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    final android.net.NetworkInfo wifi = connMgr
            .getNetworkInfo(ConnectivityManager.TYPE_WIFI);
    final android.net.NetworkInfo mobile = connMgr
            .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
    if (wifi.isAvailable()) {
        Toast.makeText(this, "Wifi", Toast.LENGTH_LONG).show();
    } else if (mobile.isAvailable()) {
        Toast.makeText(this, "Mobile 3G ", Toast.LENGTH_LONG).show();
    } else {
        Toast.makeText(this, "No Network ", Toast.LENGTH_LONG).show();
    }
}

答案 4 :(得分：1)

试试这个：

public boolean isInternetAvailable(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;

    }

和此权限：

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

答案 5 :(得分：0)

您可以尝试以下代码：

   public class NetworkCheckDemo extends Activity
 {
TextView tvstatus;
public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    tvstatus=(TextView)findViewById(R.id.txtviewstatus);
    ConnectivityManager cn=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo nf=cn.getActiveNetworkInfo();
    if(nf != null && nf.isConnected()==true )
    {
        Toast.makeText(this, "Network Available", Toast.LENGTH_LONG).show();
        tvstatus.setText("Network Available");
    }
    else
    {
        Toast.makeText(this, "Network Not Available", Toast.LENGTH_LONG).show();
        tvstatus.setText("Network Not Available");
      }
    }
  }

在Android清单文件中添加以下3个权限。

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

答案 6 :(得分：0)

我曾经检查过是否有连接，不要忘记检查NetworkInfo是否为null，因为在没有提供移动数据连接的平板电脑上，TYPE_MOBILE的NetworkInfo返回null。

public static boolean collectionAllowed(Context context) {
    ConnectivityManager connectivityManager = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo mobileInfo = connectivityManager.getNetworkInfo(
            ConnectivityManager.TYPE_MOBILE);
    State mobile = NetworkInfo.State.DISCONNECTED;
    if ( mobileInfo != null) {
        mobile = mobileInfo.getState();
    }
    NetworkInfo wifiInfo = connectivityManager.getNetworkInfo(
            ConnectivityManager.TYPE_WIFI);
    State wifi = NetworkInfo.State.DISCONNECTED;
    if ( wifiInfo != null) {
        wifi = wifiInfo.getState();
    }
    boolean dataOnWifiOnly = (Boolean) PreferenceManager
            .getDefaultSharedPreferences(context).getBoolean(
                    "data_wifi_only", true);
    if ((!dataOnWifiOnly && (mobile.equals(NetworkInfo.State.CONNECTED) || wifi
            .equals(NetworkInfo.State.CONNECTED)))
            || (dataOnWifiOnly && wifi.equals(NetworkInfo.State.CONNECTED))) {
        return true;
    } else {
        return false;
    }
}

答案 7 :(得分：0)

与批准的答案相同，但简而言之：

public static boolean isNetworkAvailable(Context context) {
    ConnectivityManager cm = (ConnectivityManager)
            context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo info = cm.getActiveNetworkInfo();
    return info != null && info.isConnected() && info.isAvailable();
}

答案 8 :(得分：0)

你可以使用这个真棒gist by emil2k：

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

public class Connectivity {
    public static NetworkInfo getNetworkInfo(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        return cm.getActiveNetworkInfo();
    }

    public static boolean isConnected(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected());
    }

    public static boolean isConnectedWifi(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI);
    }

    public static boolean isConnectedMobile(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_MOBILE);
    }

    public static boolean isConnectedFast(Context context){
        NetworkInfo info = Connectivity.getNetworkInfo(context);
        return (info != null && info.isConnected() && Connectivity.isConnectionFast(info.getType(),info.getSubtype()));
    }

    public static boolean isConnectionFast(int type, int subType){
        if(type==ConnectivityManager.TYPE_WIFI){
            return true;
        }else if(type==ConnectivityManager.TYPE_MOBILE){
            switch(subType){
            case TelephonyManager.NETWORK_TYPE_1xRTT:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_CDMA:
                return false; // ~ 14-64 kbps
            case TelephonyManager.NETWORK_TYPE_EDGE:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_0:
                return true; // ~ 400-1000 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_A:
                return true; // ~ 600-1400 kbps
            case TelephonyManager.NETWORK_TYPE_GPRS:
                return false; // ~ 100 kbps
            case TelephonyManager.NETWORK_TYPE_HSDPA:
                return true; // ~ 2-14 Mbps
            case TelephonyManager.NETWORK_TYPE_HSPA:
                return true; // ~ 700-1700 kbps
            case TelephonyManager.NETWORK_TYPE_HSUPA:
                return true; // ~ 1-23 Mbps
            case TelephonyManager.NETWORK_TYPE_UMTS:
                return true; // ~ 400-7000 kbps
            /*
             * Above API level 7, make sure to set android:targetSdkVersion 
             * to appropriate level to use these
             */
            case TelephonyManager.NETWORK_TYPE_EHRPD: // API level 11 
                return true; // ~ 1-2 Mbps
            case TelephonyManager.NETWORK_TYPE_EVDO_B: // API level 9
                return true; // ~ 5 Mbps
            case TelephonyManager.NETWORK_TYPE_HSPAP: // API level 13
                return true; // ~ 10-20 Mbps
            case TelephonyManager.NETWORK_TYPE_IDEN: // API level 8
                return false; // ~25 kbps 
            case TelephonyManager.NETWORK_TYPE_LTE: // API level 11
                return true; // ~ 10+ Mbps
            // Unknown
            case TelephonyManager.NETWORK_TYPE_UNKNOWN:
            default:
                return false;
            }
        }else{
            return false;
        }
    }

}

答案 9 :(得分：0)

此代码检查Wifi和移动设备

1-添加此权限

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

2-创建一个class以命名Internet和copy此代码

 public class Internet {

    Context context;

    public Internet(Context context) {
        this.context = context;
    }

    public boolean HaveNetworkConnection() {
        boolean haveConnectedWifi = false;
        boolean haveConnectedMobile = false;
        ConnectivityManager cm = (ConnectivityManager)context.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;
    }
}
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