你如何检查android中的互联网连接？
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How do you check the internet connection in android?
提问by UMAR
I want to check the internet connectivity in each activity. If it is lost a message should be displayed.
我想检查每个活动中的互联网连接。如果丢失，应显示一条消息。
Can any one guide me how to achieve this?
任何人都可以指导我如何实现这一目标吗？
回答by William
Only one connection can be active at any one point. So a simpler answer is:
在任一时刻只能有一个连接处于活动状态。所以更简单的答案是：
final ConnectivityManager conMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
final NetworkInfo activeNetwork = conMgr.getActiveNetworkInfo();
if (activeNetwork != null && activeNetwork.isConnected()) {
// notify user you are online
} else {
// notify user you are not online
}
It also caters for any new type of network such as ConnectivityManager#TYPE_WIMAX
它还适用于任何新型网络，例如 ConnectivityManager#TYPE_WIMAX
Also make sure that you have the required permission to monitor the network state. You need to add this permission to your AndroidManifest.xml:
还要确保您具有监视网络状态所需的权限。您需要将此权限添加到您的 AndroidManifest.xml 中：
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
回答by Dan
You can use the ConnectivityManagerto check the network state.
您可以使用ConnectivityManager来检查网络状态。
ConnectivityManager conMgr = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
if ( conMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED
|| conMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED ) {
// notify user you are online
}
else if ( conMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.DISCONNECTED
|| conMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.DISCONNECTED) {
// notify user you are not online
}
Note that the constants ConnectivityManager.TYPE_MOBILE and ConnectivityManager.TYPE_WIFI represent connection types and these two values are not exhaustive. See herefor an exhaustive list.
请注意，常量 ConnectivityManager.TYPE_MOBILE 和 ConnectivityManager.TYPE_WIFI 表示连接类型，这两个值并不详尽。有关详尽列表，请参见此处。
Also make sure that you have the required permission to monitor the network state. You need to add this permission to your AndroidManifest.xml:
还要确保您具有监视网络状态所需的权限。您需要将此权限添加到您的 AndroidManifest.xml 中：
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
回答by mainu
You can do this, for various types of network status
您可以针对各种类型的网络状态执行此操作
public void checkNetworkStatus(){
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() ){
Toast.makeText(this, "Wifi" , Toast.LENGTH_LONG).show();
}
else if( mobile.isAvailable() ){
Toast.makeText(this, "Mobile 3G " , Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(this, "No Network " , Toast.LENGTH_LONG).show();
}
}
回答by Amar Gore
You can check network coverage and data availability of Mobile and wi-fi directly with
您可以直接使用
For Network coverageavailability,
对于网络覆盖可用性，
private boolean isNetworkAvailable()
{
ConnectivityManager conxMgr = (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo mobileNwInfo = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
NetworkInfo wifiNwInfo = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
return ((mobileNwInfo== null ? false : mobileNwInfo.isAvailable()) || (wifiNwInfo == null ? false : wifiNwInfo.isAvailable()));
}
For Data availabilityif network available
对于数据的可用性，如果网络可用
private boolean isDataAvailable()
{
ConnectivityManager conxMgr = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo mobileNwInfo = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
NetworkInfo wifiNwInfo = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
return ((mobileNwInfo== null? false : mobileNwInfo.isConnected() )|| (wifiNwInfo == null? false : wifiNwInfo.isConnected()));
}
回答by Sudhakar Chavali
Correction
更正
if ( conMgr.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED
|| conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTING ) {
//notify user you are online
}
should be
应该
if ( conMgr.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED
|| conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTED ) {
//notify user you are online
}
回答by caligari
Register a broadcast receiver to handle CONNECTIVITY_ACTION. See this full example. You should update a static variable 'connectionAvailable' that will be accessible everywhere and everytime through its respective getter.
注册一个广播接收器来处理CONNECTIVITY_ACTION。请参阅此完整示例。您应该更新一个静态变量“connectionAvailable”，该变量可以通过其各自的 getter 随时随地访问。
Remember to declare the broadcast receiver in the manifestfile:
请记住在清单文件中声明广播接收器：
<receiver android:name=".NetworkConnectivityReceiver" android:enabled="true">
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
</receiver>
On the matter of 'checking in each activity', may be you would be interested in using a BaseActivity extended by your activitiesand managing the test of connectivity and displaying the message.
关于“检查每个活动”的问题，您可能对使用由您的活动扩展的BaseActivity以及管理连接测试和显示消息感兴趣。
Also, note that using events(not polling from activities) will be more efficient.
另外，请注意使用事件（不是从活动中轮询）会更有效。
回答by Naskov
You are not using ConnectivityManager.getNetworkInfo(0).getState()and ConnectivityManager.getNetworkInfo(1).getState()properly, instead of hardcoding the values (1) and (0) use ConnectivityManager.TYPE_WIFIand ConnectivityManager.TYPE_MOBILE
您没有正确使用ConnectivityManager.getNetworkInfo(0).getState()和ConnectivityManager.getNetworkInfo(1).getState()，而不是硬编码值 (1) 和 (0) 使用ConnectivityManager.TYPE_WIFI和ConnectivityManager.TYPE_MOBILE
回答by VikingGlen
This is a boolean check to see if you have network access. It doesn't determine what kind of network access - mobile, wifi..., it just checks to see if you're online.
这是一个布尔检查，用于查看您是否具有网络访问权限。它不能确定哪种网络访问 - 移动、wifi...，它只是检查您是否在线。
boolean mobileNwInfo = false;
ConnectivityManager conxMgr = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
try { mobileNwInfo = conxMgr.getActiveNetworkInfo().isConnected(); }
catch (NullPointerException e) { mobileNwInfo = false; }
if ( mobileNwInfo == false ) {
// Your code goes here...
}
