标签:api mob lse service 下载 cat return 网络连接 monitor
在做Android app的时候,网络的状态可能会经常的变化,当用户当前没有网络的时候,我们要保证程序不崩溃,而在当用户使用流量的话,则需要确保,在进行耗流量的操作的时候,需要给予用户警告(比如看视频,播放音乐,下载等).
想要获取网络状态的话,我们需要通过 ConnectivityManager
类来实现,该类负责与 NetworkManagementService
系统服务进行交互来获取网络相关的信息。我们先来看一下官方文档是如何描述这个类的:
Class that answers queries about the state of network connectivity. It also notifies applications when network connectivity changes.
该类负责回答关于网络连接的状态的问题。 当网络连接发生改变的时候也会通知应用。
The primary responsibilities of this class are to:
该类的主要责任是:
可以通过下面的方式获取此类的实例
val connectivityManager: ConnectivityManager =
context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
val connectivityManager: ConnectivityManager =
context.getSystemService(ConnectivityManager::class.java) as ConnectivityManager
小贴士,请不要忘记添加
android.permission.ACCESS_NETWORK_STATE
权限。
NetworkInfo 是一个描述网络连接状态的接口,我们主要通过这个类来获取网络的状态。
val connectivityManager: ConnectivityManager =
context.getSystemService(ConnectivityManager::class.java) as ConnectivityManager
val networkInfo = connectivityManager.activeNetworkInfo
/**
* 判断网络是否可用
* */
fun isAvailable(context: Context): Boolean {
val connectivityManager: ConnectivityManager =
context.getSystemService(ConnectivityManager::class.java) as ConnectivityManager
val networkInfo = connectivityManager.activeNetworkInfo
if (networkInfo != null) {
return networkInfo.isAvailable
}
return false
}
fun isMobile(context: Context): Boolean {
val connectivityManager: ConnectivityManager =
context.getSystemService(ConnectivityManager::class.java) as ConnectivityManager
val networkInfo = connectivityManager.activeNetworkInfo
if (networkInfo != null) {
return networkInfo.type == ConnectivityManager.TYPE_MOBILE
}
return false
}
从官方文档我们可以知道,如果要想监听到网络的变化的,那么需要我们动态注册一个广播才行。
val networkStatusChangeReceiver = object : BroadcastReceiver() {
@SuppressLint("ServiceCast")
override fun onReceive(context: Context?, intent: Intent?) {
val connectivityManager: ConnectivityManager =
context!!.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
val networkInfo = connectivityManager.activeNetworkInfo
if (networkInfo != null && networkInfo.isAvailable) {
tvNetworkStatus.text = "Current Network Status: Available"
} else {
tvNetworkStatus.text = "Current Network Status: unavailable"
}
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
//注册一个广播
val filter = IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION)
this.registerReceiver(this.networkStatusChangeReceiver, filter)
}
override fun onDestroy() {
this.unregisterReceiver(this.networkStatusChangeReceiver)
super.onDestroy()
}
标签:api mob lse service 下载 cat return 网络连接 monitor
原文地址:https://www.cnblogs.com/slyfox/p/9754619.html