如何在Android设备上以编程方式检查网络是否可用，当我们尝试连接到Wifi和3G等网络时，如何抛出消息或Toast消息。
10个回答
55
为了在开始活动之前检查网络，即3G或WiFi是否可用，我们可以使用以下方法进行验证。
ConnectivityManager manager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
//For 3G check
boolean is3g = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)
.isConnectedOrConnecting();
//For WiFi Check
boolean isWifi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI)
.isConnectedOrConnecting();
System.out.println(is3g + " net " + isWifi);
if (!is3g && !isWifi)
{
Toast.makeText(getApplicationContext(),"Please make sure your Network Connection is ON ",Toast.LENGTH_LONG).show();
}
else
{
" Your method what you want to do "
}
希望这能帮助到某些人。
- Rahul Baradia
5
1你可以在这里获取相关信息：http://rahulbaradiaa.blogspot.in/2012/07/check-wifi-3g-availability-on-android.html - Rahul Baradia
2空指针异常：boolean is3g = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).isConnectedOrConnecting(); - benoffi7
3正如@benoffi7所说，你需要在调用isConnectedOrConnecting()方法之前测试manager.getNetworkInfo(ConnectivityManager.*)不为空。 - Kikiwa
"getInfoNetwork(int)"现已被弃用。仅供记录（请参阅此StackOverflow答案获取更新版本）。 - Anwar
1getNetworkInfo()现在已经过时了，因为例如：如果设备上有2个蜂窝网络。 - HungNM2
7
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() && wifi.getDetailedState() == DetailedState.CONNECTED){
Toast.makeText(this, "Wifi" , Toast.LENGTH_LONG).show();
}
else if( mobile.isAvailable() && mobile.getDetailedState() == DetailedState.CONNECTED ){
Toast.makeText(this, "Mobile 3G " , Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(this, "No Network " , Toast.LENGTH_LONG).show();
}
这段代码检查你当前是否连接着wifi或者是使用3G网络，如果你的wifi打开了但是没有连接网络或者是3G信号不稳定，它会用DetailedStates来检测这些细节。
- Agustin Gandara
6
您可以使用此方法来检查您的互联网连接是2G、3G还是4G:
public String getNetworkClass(Context context) {
TelephonyManager mTelephonyManager = (TelephonyManager)
context.getSystemService(Context.TELEPHONY_SERVICE);
int networkType = mTelephonyManager.getNetworkType();
switch (networkType) {
case TelephonyManager.NETWORK_TYPE_GPRS:
case TelephonyManager.NETWORK_TYPE_EDGE:
case TelephonyManager.NETWORK_TYPE_CDMA:
case TelephonyManager.NETWORK_TYPE_1xRTT:
case TelephonyManager.NETWORK_TYPE_IDEN:
return "2G";
case TelephonyManager.NETWORK_TYPE_UMTS:
case TelephonyManager.NETWORK_TYPE_EVDO_0:
case TelephonyManager.NETWORK_TYPE_EVDO_A:
case TelephonyManager.NETWORK_TYPE_HSDPA:
case TelephonyManager.NETWORK_TYPE_HSUPA:
case TelephonyManager.NETWORK_TYPE_HSPA:
case TelephonyManager.NETWORK_TYPE_EVDO_B:
case TelephonyManager.NETWORK_TYPE_EHRPD:
case TelephonyManager.NETWORK_TYPE_HSPAP:
return "3G";
case TelephonyManager.NETWORK_TYPE_LTE:
return "4G";
default:
return "Unknown";
}
}
使用以下方法可以检查 是否有可用的互联网连接，并获取您是通过移动网络还是WiFi访问互联网:
public String getNetworkType(Context context){
String networkType = null;
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = connectivityManager.getActiveNetworkInfo();
if (activeNetwork != null) { // connected to the internet
if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
networkType = "WiFi";
} else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
networkType = "Mobile";
}
} else {
// not connected to the internet
}
return networkType;
}
- zeeali
3
这对我有用。
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
String name networkInfo.getTypeName();
- benoffi7
3
Rahul Baradia的答案中包括manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)，然而已被弃用。
以下是针对最新Android SDK的改进方案。
ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);
boolean is3gEnabled = false;
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
Network[] networks = connManager.getAllNetworks();
for(Network network: networks)
{
NetworkInfo info = connManager.getNetworkInfo(network);
if(info!=null) {
if (info.getType() == ConnectivityManager.TYPE_MOBILE) {
is3gEnabled = true;
break;
}
}
}
}
else
{
NetworkInfo mMobile = connManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if(mMobile!=null)
is3gEnabled = true;
}
- Krzysztof Huminski
1
我们可以使用ConnectivityManager Class来获取与网络相关的任何信息。
它还会在网络连接状态更改时通知应用程序。通过调用此类的实例来获取一个实例。
该类的主要职责是：
它还会在网络连接状态更改时通知应用程序。通过调用此类的实例来获取一个实例。
该类的主要职责是：
- 监视网络连接（Wi-Fi、GPRS、UMTS等）
- 在网络连接状态更改时发送广播意图
- 当与网络的连接丢失时，尝试“故障转移”到另一个网络
- 提供API，允许应用程序查询可用网络的粗粒度或细粒度状态
- 提供API，允许应用程序请求和选择其数据流量的网络
GetNetworkInfo function return status information about a particular network type.
This method requires the caller to hold the permission
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
/**
* Checks the type of data connection that is currently available on the device.
*
* @return <code>ConnectivityManager.TYPE_*</code> as a type of internet connection on the
*This method does not support multiple connected networks
* of the same type.
* device. Returns -1 in case of error or none of
* <code>ConnectivityManager.TYPE_*</code> is found.
**/
--
public static int getDataConnectionType(Context ctx) {
ConnectivityManager connectivityManager = (ConnectivityManager) ctx.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivityManager != null && connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE) != null) {
if (connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).isConnected()) {
return ConnectivityManager.TYPE_MOBILE;
} else if (connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnected()) {
return ConnectivityManager.TYPE_WIFI;
} else
return -1;
} else
return -1;
}
- A-Droid Tech
1
仅返回与网络类型连接的内容，不返回用户启用的类型。 - kemdo
1
请将以下代码用作 NetworkChecker.java 并在您的代码中重复使用：
package das.soumyadip.util;
import android.net.ConnectivityManager;
import android.util.Log;
public class NetworkChecker {
private final static String TAG = "NwtworkChecker";
public static boolean isNetworkConnected(
final ConnectivityManager connectivityManager) {
boolean val = false;
Log.d(TAG, "Checking for Mobile Internet Network");
final android.net.NetworkInfo mobile = connectivityManager
.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if (mobile.isAvailable() && mobile.isConnected()) {
Log.i(TAG, "Found Mobile Internet Network");
val = true;
} else {
Log.e(TAG, "Mobile Internet Network not Found");
}
Log.d(TAG, "Checking for WI-FI Network");
final android.net.NetworkInfo wifi = connectivityManager
.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (wifi.isAvailable() && wifi.isConnected()) {
Log.i(TAG, "Found WI-FI Network");
val = true;
} else {
Log.e(TAG, "WI-FI Network not Found");
}
return val;
}
}
- Soumyadip Das
1
1为什么关闭了Wi-Fi（或3G）会出现错误（Log.e(TAG，“WI-FI网络未找到”）0_0？这对于手机和许多可以在没有它的情况下工作（可能是其中一部分）的应用程序来说是一个有效的情况。为什么在此类实用程序中有如此多的日志记录，而不是关键任务代码？ - Denis Gladkiy
1
// TODO Auto-generated method stub
ConnectivityManager connMgr =
(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
final android.net.NetworkInfo mobile = connectivityManager
.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if (mobile.isAvailable() && mobile.isConnected()) {
Log.i(TAG, "Found Mobile Internet Network");
val = true;
}
// Checks the user prefs and the network connection. Based on the result, decides
// whether
// to refresh the display or keep the current display.
// If the userpref is Wi-Fi only, checks to see if the device has a Wi-Fi connection.
if (WIFI.equals(sPref) && networkInfo != null
&& networkInfo.getType() == ConnectivityManager.TYPE_WIFI) {
// If device has its Wi-Fi connection, sets refreshDisplay
// to true. This causes the display to be refreshed when the user
// returns to the app.
refreshDisplay = true;
Toast.makeText(context, R.string.wifi_connected, Toast.LENGTH_SHORT).show();
// If the setting is ANY network and there is a network connection
// (which by process of elimination would be mobile), sets refreshDisplay to true.
}
}
else if (ANY.equals(sPref) && networkInfo != null) {
refreshDisplay = true;
// Otherwise, the app can't download content--either because there is no network
// connection (mobile or Wi-Fi), or because the pref setting is WIFI, and there
// is no Wi-Fi connection.
// Sets refreshDisplay to false.
} else {
refreshDisplay = false;
Toast.makeText(context, R.string.lost_connection, Toast.LENGTH_SHORT).show();
}
- Maidul
1
public boolean isInternetAvailable(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
if (activeNetwork != null) { // connected to the internet
if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
// connected to wifi
return true;
} else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
// connected to the mobile provider's data plan
return true;
}
} else {
// not connected to the internet
return false;
}
return false;
}
- Bilawal sharif
0
在上面的代码中，我没有看到对getNetworkInfo()返回null的检查，根据文档，当请求的网络类型不受支持时会发生这种情况。这意味着在没有3G的设备上，应用程序将因为空指针异常而崩溃。
- Macs
网页内容由stack overflow 提供, 点击上面的可以查看英文原文，
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