Question

我是android开发的新生，所以我没有足够的编码经验，所以我需要你的帮助...... 我在android studio上创建一个java类来检查是否有互联网连接：

import android.app.Activity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;


public class InternetStatus {
private static final String LOG_TAG ="InternetStatus";
public static boolean hasActiveInternetConnection(Context context) {
    if (isNetworkAvailable((Activity) context)) {
        try {
            HttpURLConnection urlc = (HttpURLConnection) (new     URL("http://www.google.com").openConnection());
            urlc.setRequestProperty("User-Agent", "Test");
            urlc.setRequestProperty("Connection", "close");
            urlc.setConnectTimeout(1500);
            urlc.connect();
            return (urlc.getResponseCode() == 200);
        } catch (IOException e) {
            Log.e(LOG_TAG, "Error checking internet connection", e);
        }
    } else {
        Log.d(LOG_TAG, "No network available!");
    }
    return false;
}
public static boolean isNetworkAvailable(Activity mActivity) {
    Context context = mActivity.getApplicationContext();
    ConnectivityManager connectivity = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    if (connectivity == null) {
        return false;
    } else {
        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;
}


}

所以，我有两个问题：

1-这是正确的代码还是我遗漏了什么？

2-如你所见，这是一个java类，如果我在主活动上创建一个按钮来检查是否有互联网连接！我怎么能通过导入这个类或类似的东西来做到这一点？!!

Answer 1

// Check if there is any connectivity for a Wifi network
public boolean isConnectedWifi(){
    NetworkInfo info = Connectivity.getNetworkInfo(Context);

    if (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI){
    return true;
    }
    return false;
}

// Check if there is any connectivity for a mobile network
public boolean isConnectedMobile(){
    NetworkInfo info = Connectivity.getNetworkInfo(Context);
    if(info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_MOBILE){
    return true;
    }
    return false;
}

// Check all connectivities whether available or not
public boolean isNetworkAvailable() {
    ConnectivityManager cm = (ConnectivityManager) 
      getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = cm.getActiveNetworkInfo();
    // if no network is available networkInfo will be null
    // otherwise check if we are connected
    if (networkInfo != null && networkInfo.isConnected()) {
        return true;
    }
    return false;
}

如何使用？

例如，我们需要检查连接是否可用：

if(isNetworkAvailable()){
    // do your thing here.
}

当网络可用时，我们需要检查它是WiFi还是移动网络：

if(isConnectedWifi()){
    // do your thing here with WiFi Network.
}

if(isConnectedMobile()){
    // do your thing here with Mobile Network.
}

Answer 2

首先，您必须在 AndroidManifest.xml

中包含权限请求

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

然后，创建方法以检查互联网连接是否处于活动状态：

public static boolean isInternetConnected(Context context) {
    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();

    return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
}

Answer 3

在MainActivity班级

@Override
protected void onCreate (Bundle savedInstanceState) {

super.onCreate (savedInstanceState);
    setContentView (R.layout.activity_camera);
     boolean isavailable = InternetStatus.hasActiveInternetConnection(getApplicationContext);
    }
}

如果你有一个按钮

boolean isavailable ;
@Override
protected void onCreate (Bundle savedInstanceState) {

super.onCreate (savedInstanceState);
    setContentView (R.layout.activity_camera);
     Button someButton = (Button) findViewById(R.id.yourButton);
     someButton.setOnClickListener(new onClickLIstener(){
               isavailable = InternetStatus.hasActiveInternetConnection(getApplicationContext);
     });
    }
}

Answer 4

要检查连接状态，无需连接到互联网并获取状态代码。使用以下代码。

public boolean isConnected() {
    ConnectivityManager manager = (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE);
    NetworkInfo info = manager.getActiveNetworkInfo();
    if (info != null && info.isConnected()) {
        return true;
    } else {
        return false;

    }
}

根据活动网络状态返回true或false。

在按钮上单击只需调用此函数，如果返回true，则表示存在连接。如果返回false，则表示没有活动的Internet连接。

Answer 5

将info.isConnected（）放入isNetworkAvailable函数中：

  public static boolean isNetworkAvailable(Activity mActivity) {
            ...
        if (connectivity == null) {
            return false;
        } else {
            NetworkInfo[] info = connectivity.getAllNetworkInfo();
                if (info != null && info.isConnected()) {
                    ...
                    }
                }
            }
            return false;
        }

Answer 6

大多数答案已经过时了

    fun isNetworkAvailable(context : Context): Boolean {
        val connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
        if (isAndroidVersionAboveLollipop()) {
            val activeNetwork = connectivityManager.activeNetwork ?: return false
            val networkCapabilities = connectivityManager.getNetworkCapabilities(activeNetwork) ?: return false
            networkCapabilities.let {
                return it.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) && it.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)
            }
        } else {
              return connectivityManager.activeNetworkInfo?.isConnectedOrConnecting ?: false
         }
    }

    fun isAndroidVersionAboveLollipop() = Build.VERSION.SDK_INT >= Build.VERSION_CODES.M

检查主要活动的互联网状态

6 个答案: