我不希望我的用户尝试下载任何东西，除非他们连接了Wi-Fi。然而，我似乎只能判断是否启用了Wi-Fi，但他们仍然可能有3G连接。
android.net.wifi.WifiManager m = (WifiManager) getSystemService(WIFI_SERVICE);
android.net.wifi.SupplicantState s = m.getConnectionInfo().getSupplicantState();
NetworkInfo.DetailedState state = WifiInfo.getDetailedStateOf(s);
if (state != NetworkInfo.DetailedState.CONNECTED) {
return false;
}
然而，这种状态并不是我所期望的。即使Wi-Fi是连接的，我得到OBTAINING_IPADDR作为状态。
当前回答
虽然Jason的回答是正确的，但现在getNetWorkInfo (int)是一个不推荐使用的方法。所以，下一个函数将是一个很好的选择:
public static boolean isWifiAvailable (Context context)
{
boolean br = false;
ConnectivityManager cm = null;
NetworkInfo ni = null;
cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
ni = cm.getActiveNetworkInfo();
br = ((null != ni) && (ni.isConnected()) && (ni.getType() == ConnectivityManager.TYPE_WIFI));
return br;
}
其他回答
我在我的应用程序中使用这个来检查活动网络是否为Wi-Fi:
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo ni = cm.getActiveNetworkInfo();
if (ni != null && ni.getType() == ConnectivityManager.TYPE_WIFI)
{
// Do your work here
}
ConnectivityManager manager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
boolean is3g = manager.getNetworkInfo(
ConnectivityManager.TYPE_MOBILE).isConnectedOrConnecting();
boolean isWifi = manager.getNetworkInfo(
ConnectivityManager.TYPE_WIFI).isConnectedOrConnecting();
Log.v("", is3g + " ConnectivityManager Test " + isWifi);
if (!is3g && !isWifi) {
Toast.makeText(
getApplicationContext(),
"Please make sure, your network connection is ON ",
Toast.LENGTH_LONG).show();
}
else {
// Put your function() to go further;
}
下面是我在我的应用程序中使用的实用方法:
public static boolean isDeviceOnWifi(final Context context) {
ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
return mWifi != null && mWifi.isConnectedOrConnecting();
}
你可以打开WIFI，如果它没有被激活如下 1. 查看@Jason Knight回复的WIFI状态 2. 如果没有激活，请激活它 不要忘记在manifest文件中添加WIFI权限
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
您的Java类应该是这样的
public class TestApp extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//check WIFI activation
ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (mWifi.isConnected() == false) {
showWIFIDisabledAlertToUser();
}
else {
Toast.makeText(this, "WIFI is Enabled in your devide", Toast.LENGTH_SHORT).show();
}
}
private void showWIFIDisabledAlertToUser(){
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
alertDialogBuilder.setMessage("WIFI is disabled in your device. Would you like to enable it?")
.setCancelable(false)
.setPositiveButton("Goto Settings Page To Enable WIFI",
new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int id){
Intent callGPSSettingIntent = new Intent(
Settings.ACTION_WIFI_SETTINGS);
startActivity(callGPSSettingIntent);
}
});
alertDialogBuilder.setNegativeButton("Cancel",
new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int id){
dialog.cancel();
}
});
AlertDialog alert = alertDialogBuilder.create();
alert.show();
}
}
虽然Jason的回答是正确的，但现在getNetWorkInfo (int)是一个不推荐使用的方法。所以，下一个函数将是一个很好的选择:
public static boolean isWifiAvailable (Context context)
{
boolean br = false;
ConnectivityManager cm = null;
NetworkInfo ni = null;
cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
ni = cm.getActiveNetworkInfo();
br = ((null != ni) && (ni.isConnected()) && (ni.getType() == ConnectivityManager.TYPE_WIFI));
return br;
}
