Android Wifi的forget()操作实例详解
我们在处理某个Wifi连接时，有时会需要忘掉当前连接的密码信息。执行这项操作，我们需要调用WifiManager::forget()函数：
/** * Delete the network in the supplicant config. * * This function is used instead of a sequence of removeNetwork() * and saveConfiguration(). * * @param config the set of variables that describe the configuration, * contained in a {@link WifiConfiguration} object. * @param listener for callbacks on success or failure. Can be null. * @throws IllegalStateException if the WifiManager instance needs to be * initialized again * @hide */ public void forget(int netId, ActionListener listener) { if (netId < 0) throw new IllegalArgumentException("Network id cannot be negative"); validateChannel(); sAsyncChannel.sendMessage(FORGET_NETWORK, netId, putListener(listener)); }
从函数介绍可知，调用forget()函数，当前网络连接的配置信息就会从wpa_supplicant.conf中删掉；之后这个网络就不会有自动重连的动作，因为conf文件中已经没有该网络的配置信息。
跟踪FORGET_NETWORK消息，WifiServiceImpl::ClientHandler处理：
case WifiManager.FORGET_NETWORK: if (isOwner(msg.sendingUid)) { mWifiStateMachine.sendMessage(Message.obtain(msg)); } else { Slog.e(TAG, "Forget is not authorized for user"); replyFailed(msg, WifiManager.FORGET_NETWORK_FAILED, WifiManager.NOT_AUTHORIZED); } break;
简单地将该消息转发给WifiStateMachine。此时Wifi是连接状态，WifiStateMachine中当前状态是ConnectedState，它的父状态ConnectModeState处理：
case WifiManager.FORGET_NETWORK: // Debug only, remember last configuration that was forgotten WifiConfiguration toRemove = mWifiConfigStore.getWifiConfiguration(message.arg1); if (toRemove == null) { lastForgetConfigurationAttempt = null; } else { lastForgetConfigurationAttempt = new WifiConfiguration(toRemove); } // check that the caller owns this network netId = message.arg1; if (!mWifiConfigStore.canModifyNetwork(message.sendingUid, netId, /* onlyAnnotate */ false)) { logw("Not authorized to forget network " + " cnid=" + netId + " uid=" + message.sendingUid); replyToMessage(message, WifiManager.FORGET_NETWORK_FAILED, WifiManager.NOT_AUTHORIZED); break; } if (mWifiConfigStore.forgetNetwork(message.arg1)) { replyToMessage(message, WifiManager.FORGET_NETWORK_SUCCEEDED); broadcastWifiCredentialChanged(WifiManager.WIFI_CREDENTIAL_FORGOT, (WifiConfiguration) message.obj); } else { loge("Failed to forget network"); replyToMessage(message, WifiManager.FORGET_NETWORK_FAILED, WifiManager.ERROR); } break;
mWifiConfigStore.forgetNetwork()：
/** * Forget the specified network and save config * * @param netId network to forget * @return {@code true} if it succeeds, {@code false} otherwise */ boolean forgetNetwork(int netId) { if (showNetworks) localLog("forgetNetwork", netId); WifiConfiguration config = mConfiguredNetworks.get(netId); boolean remove = removeConfigAndSendBroadcastIfNeeded(netId); if (!remove) { //success but we dont want to remove the network from supplicant conf file return true; } if (mWifiNative.removeNetwork(netId)) { if (config != null && config.isPasspoint()) { writePasspointConfigs(config.FQDN, null); } mWifiNative.saveConfig(); writeKnownNetworkHistory(true); return true; } else { loge("Failed to remove network " + netId); return false; } }
根据传入的当前网络的netId，分别调用WifiNative的removeNetwork()、saveConfig()方法删除conf文件的配置信息并进行保存；执行完成后，forget()函数结束了。通过代码我们发现，执行forget()函数并不会引起WifiStateMachine中状态的切换。
感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！
临行之前，面对太多的疑问和不解：为何是一个人？
