检测android设备是否已连接到互联网 [英] Detect if android device is connected to the internet

问题描述

这是我的课程，检查设备是否已连接到互联网。

this is my class that checks if the device is connected to the internet.

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 ConnectionDetector {
    private Context _context;

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

    public boolean isConnectingToInternet() {
        if (networkConnectivity()) {
            try {
                HttpURLConnection urlc = (HttpURLConnection) (new URL(
                        "http://www.google.com").openConnection());
                urlc.setRequestProperty("User-Agent", "Test");
                urlc.setRequestProperty("Connection", "close");
                urlc.setConnectTimeout(3000);
                urlc.setReadTimeout(4000);
                urlc.connect();
                // networkcode2 = urlc.getResponseCode();
                return (urlc.getResponseCode() == 200);
            } catch (IOException e) {
                return (false);
            }
        } else
            return false;

    }

    private boolean networkConnectivity() {
    ConnectivityManager cm = (ConnectivityManager) _context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = cm.getActiveNetworkInfo();
    if (networkInfo != null && networkInfo.isConnected()) {
        return true;
    }
    return false;
}

}

然后我在这里称呼它似乎没有返回true或false。没有错误，我的应用程序不会崩溃，只是不打印任何内容。有人知道为什么吗？

then i call it here but it doesnt seem to return true or false. there are no errors and my app doesnt crash it just doesnt print anything out. anyone know why?

public void CheckInternet(){

   // Boolean isInternetPresent;

    ConnectionDetector cd = new ConnectionDetector(getApplicationContext());

 //   isInternetPresent = cd.isConnectingToInternet();

    if (cd.isConnectingToInternet()) {
        // Internet Connection is Present

        Log.i(TAG, "INTERNET IS GUUD");

    } else {
        // Internet connection is not present
        // Ask user to connect to Internet
        Log.i(TAG, "INTERNET IS NOOOO GUUD");

    }
}

推荐答案

创建一个类：

public class Utility {
    public static boolean isNetworkAvailable(Context context) {
        ConnectivityManager connectivityManager
                = (ConnectivityManager)  context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo != null && activeNetworkInfo.isConnected();
    }
}

然后您从活动中调用methode，它将返回true或否：

Then you call methode from activity, it will return true or false:

Utility.isNetworkAvailable(AnyActivity.this);

别忘了向Android清单添加权限

And don't forget to add permission to android manifest

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

这篇关于检测android设备是否已连接到互联网的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！