Expo 网络
提供对设备网络的访问（例如其 IP 地址、MAC 地址和飞行模式状态）的库。
expo-network 提供有关设备网络的有用信息，例如 IP 地址、MAC 地址和飞行模式状态。
¥expo-network provides useful information about the device's network such as its IP address, MAC address, and airplane mode status.
安装
¥Installation
- npx expo install expo-networkIf you are installing this in an existing React Native app, make sure to install expo in your project.
配置
¥Configuration
在 Android 上，该模块需要访问网络和 Wi-Fi 状态的权限。权限 ACCESS_NETWORK_STATE 和 ACCESS_WIFI_STATE 是自动添加的。
¥On Android, this module requires permissions to access the network and Wi-Fi state. The permissions ACCESS_NETWORK_STATE and ACCESS_WIFI_STATE are added automatically.
API
import * as Network from 'expo-network';
Hooks
Returns the current network state of the device. This method initiates a listener for network state changes and cleans up before unmounting.
NetworkStateThe current network state of the device, including connectivity and type.
Example
const networkState = useNetworkState();
console.log(`Current network type: ${networkState.type}`);
Methods
Gets the device's current IPv4 address. Returns 0.0.0.0 if the IP address could not be retrieved.
On web, this method uses the third-party ipify service to get the
public IP address of the current device.
Promise<string>A Promise that fulfils with a string of the current IP address of the device's main
network interface. Can only be IPv4 address.
Example
await Network.getIpAddressAsync();
// "92.168.32.44"
Gets the device's current network connection state.
On web, navigator.connection.type is not available on browsers. So if there is an active
network connection, the field type returns NetworkStateType.UNKNOWN. Otherwise, it returns
NetworkStateType.NONE.
Promise<NetworkState>A Promise that fulfils with a NetworkState object.
Example
await Network.getNetworkStateAsync();
// {
// type: NetworkStateType.CELLULAR,
// isConnected: true,
// isInternetReachable: true,
// }
Tells if the device is in airplane mode.
Promise<boolean>Returns a Promise that fulfils with a boolean value for whether the device is in
airplane mode or not.
Example
await Network.isAirplaneModeEnabledAsync();
// false
Event Subscriptions
| Parameter | Type | Description |
|---|---|---|
| listener | (event: NetworkState) => void | Callback to execute when the network state changes. The callback is provided with a single argument that is an object containing information about the network state. |
Adds a listener that will fire whenever the network state changes.
EventSubscriptionA subscription object with a remove function to unregister the listener.
Example
const subscription = addNetworkStateListener(({ type, isConnected, isInternetReachable }) => {
console.log(`Network type: ${type}, Connected: ${isConnected}, Internet Reachable: ${isInternetReachable}`);
});
Types
| Property | Type | Description |
|---|---|---|
| isConnected(optional) | boolean | If there is an active network connection. Note that this does not mean that internet is reachable.
This field is |
| isInternetReachable(optional) | boolean | If the internet is reachable with the currently active network connection. On Android, this
depends on |
| type(optional) | NetworkStateType | A |
Type: NetworkState
Represents an event that provides the updated network state when there is a change in the network status.
This is passed as the argument to listeners registered with addNetworkStateListener().
Enums
An enum of the different types of devices supported by Expo.
NetworkStateType.CELLULAR ＝ "CELLULAR"Active network connection over mobile data or DUN-specific
mobile connection when setting an upstream connection for tethering.
NetworkStateType.OTHER ＝ "OTHER"Active network connection over other network connection types.
错误代码
¥Error codes
| 代码 | 描述 |
|---|---|
| ERR_NETWORK_IP_ADDRESS | 在 Android 上，尝试在 getIpAddressAsync 中访问 WifiManager 时可能存在未知的 Wi-Fi 主机。在 iOS 上，无法检索网络接口。 |
| ERR_NETWORK_UNDEFINED_INTERFACE | 未定义的 interfaceName 作为参数传递到 getMacAddressAsync 中。 |
| ERR_NETWORK_SOCKET_EXCEPTION | 创建或访问 getMacAddressAsync 中的套接字时遇到错误。 |
| ERR_NETWORK_INVALID_PERMISSION_INTERNET | getMacAddressAsync 中存在 android.permission.ACCESS_WIFI_STATE 的无效权限。 |
| ERR_NETWORK_NO_ACCESS_NETWORKINFO | 无法访问网络信息 |