Question

我正在使用此代码：

public boolean isOnline() {
     ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
     return cm.getActiveNetworkInfo().isConnectedOrConnecting();

    }

但它总是返回true。谁能告诉我为什么？此外，此功能检查设备是使用wifi还是3g连接，还是仅检查其中一个？

Answer 1

尝试这种方法，适合我

private boolean isNetworkAvailable() {
    ConnectivityManager connectivityManager 
          = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
    if (activeNetworkInfo != null)
        return activeNetworkInfo.isConnected();
    return false;
}

Answer 2

使用此代码并检查您的权限。有时也可能导致问题。抱歉格式化。

 public final boolean isInternetOn() {
ConnectivityManager connec =  (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
// ARE WE CONNECTED TO THE NET
if ( connec.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED ||
connec.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTING ||
connec.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTING ||
connec.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTED ) {
// MESSAGE TO SCREEN FOR TESTING (IF REQ)
//Toast.makeText(this, connectionType + ” connected”, Toast.LENGTH_SHORT).show();
return true;
} else if ( connec.getNetworkInfo(0).getState() == NetworkInfo.State.DISCONNECTED ||  connec.getNetworkInfo(1).getState() == NetworkInfo.State.DISCONNECTED  ) {
//System.out.println(“Not Connected”);
return false;
}
return false;
}

以下代码演示了如何调用上述方法;

 if(isInternetOn()) {
// INTERNET IS AVAILABLE, DO STUFF..
return true;
}else{
// NO INTERNET AVAILABLE, DO STUFF..
return false;
}

Answer 3

我用它，它允许我检查一个特定的连接（3g或wifi）（在SO上找到但丢失了参考，对不起）

public boolean isConnected() {
    boolean connectedWifi = false;
    boolean connectedMobile = false;

    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo[] networks = cm.getAllNetworkInfo();
    for (NetworkInfo ni : networks) {
        if ("WIFI".equalsIgnoreCase(ni.getTypeName()))
            if (ni.isConnected())
                connectedWifi = true;
        if ("MOBILE".equalsIgnoreCase(ni.getTypeName()))
            if (ni.isConnected())
                connectedMobile = true;
    }
    return connectedWifi || connectedMobile;
}

Answer 4

如果你想知道你的Android设备是否连接到任何网络，那么你可以按照其他人告诉你的方法。

但是如果你想知道互联网是否有效，那么android中没有API来检查它。了解互联网是否正常工作的唯一方法是检查我向任何网址发送http请求。

Answer 5

以下代码适用于我

public static boolean haveNetworkConnection(Activity activity) {
        int airplane_mode_on = Settings.System.getInt(activity
                .getApplicationContext().getContentResolver(),
                Settings.System.AIRPLANE_MODE_ON, 0);
        if (airplane_mode_on == 1) {
            return false;
        } else {
            return checkInternetConnection(activity);
        }
    }

    private static boolean checkInternetConnection(Context context) {
        ConnectivityManager conMgr = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        if (conMgr.getActiveNetworkInfo() != null
                && conMgr.getActiveNetworkInfo().isAvailable()
                && conMgr.getActiveNetworkInfo().isConnected()) {
            return true;
        } else {
            return false;
        }
    }

检查设备是否已连接到互联网不起作用的Android代码

5 个答案: