http://blog.csdn.net/cljfqyd/article/details/8863694
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[java] view plain copy <span style="font-family: Arial, Helvetica, sans-serif;">Settings 中的WIFI功能主要在package/Settings/src/com/android/wifi/WifiSettings实现</span>
首先我们来看下WifiSettings类声明
[java] view plain copy public class WifiSettings extends SettingsPreferenceFragment implements DialogInterface.OnClickListener { ...... } 继承SettingsPreferenceFragment，可见它是一个Fragment我们看到源码中的描述是这样的
/** * Two types of UI are provided here. * * The first is for "usual Settings", appearing as any other Setup fragment. * * The second is for Setup Wizard, with a simplified interface that hides the action bar * and menus. */
一、注册广播，接受相关wifi信息变化
WifiSettins类主要负责监测wifi状态，以及加载各个连接点，并负责Fragment界面的显示。 在WifiSettings类中比较重要的一个类是WifiManager(稍后再说,一步一步来). 在WifiSettings构造函数中初始化一个BroadcastReceiver，该BroadcastReceiver监测外部广播
[java] view plain copy public class WifiSettings extends SettingsPreferenceFragment implements DialogInterface.OnClickListener { ...... public WifiSettings() { mFilter = new IntentFilter();//添加过滤器 mFilter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION); mFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION); mFilter.addAction(WifiManager.NETWORK_IDS_CHANGED_ACTION); mFilter.addAction(WifiManager.SUPPLICANT_STATE_CHANGED_ACTION); mFilter.addAction(WifiManager.CONFIGURED_NETWORKS_CHANGED_ACTION); mFilter.addAction(WifiManager.LINK_CONFIGURATION_CHANGED_ACTION); mFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION); mFilter.addAction(WifiManager.RSSI_CHANGED_ACTION); mReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { handleEvent(context, intent);//事件处理函数 } }; mScanner = new Scanner(); } ...... @Override public void onResume() { super.onResume(); if (mWifiEnabler != null) { mWifiEnabler.resume(); } getActivity().registerReceiver(mReceiver, mFilter);//在onResume注册广播，获得相关wifi信息 if (mKeyStoreNetworkId != INVALID_NETWORK_ID && KeyStore.getInstance().state() == KeyStore.State.UNLOCKED) { mWifiManager.connect(mChannel, mKeyStoreNetworkId, mConnectListener); } mKeyStoreNetworkId = INVALID_NETWORK_ID; updateAccessPoints(); } ...... @Override public void onPause() { super.onPause(); if (mWifiEnabler != null) { mWifiEnabler.pause(); } getActivity().unregisterReceiver(mReceiver);//在onPause注销广播 mScanner.pause(); } ...... } 广播的处理事件代码：
[java] view plain copy private void handleEvent(Context context, Intent intent) { String action = intent.getAction(); if (WifiManager.WIFI_STATE_CHANGED_ACTION.equals(action)) { updateWifiState(intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN)); } else if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(action) || WifiManager.CONFIGURED_NETWORKS_CHANGED_ACTION.equals(action) || WifiManager.LINK_CONFIGURATION_CHANGED_ACTION.equals(action)) { updateAccessPoints(); } else if (WifiManager.SUPPLICANT_STATE_CHANGED_ACTION.equals(action)) { //Ignore supplicant state changes when network is connected //TODO: we should deprecate SUPPLICANT_STATE_CHANGED_ACTION and //introduce a broadcast that combines the supplicant and network //network state change events so the apps dont have to worry about //ignoring supplicant state change when network is connected //to get more fine grained information. SupplicantState state = (SupplicantState) intent.getParcelableExtra( WifiManager.EXTRA_NEW_STATE); if (!mConnected.get() && SupplicantState.isHandshakeState(state)) { updateConnectionState(WifiInfo.getDetailedStateOf(state)); } } else if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(action)) { NetworkInfo info = (NetworkInfo) intent.getParcelableExtra( WifiManager.EXTRA_NETWORK_INFO); mConnected.set(info.isConnected()); changeNextButtonState(info.isConnected()); updateAccessPoints(); updateConnectionState(info.getDetailedState()); if (mAutoFinishOnConnection && info.isConnected()) { getActivity().finish(); return; } } else if (WifiManager.RSSI_CHANGED_ACTION.equals(action)) { updateConnectionState(null); } } 二、WifiMananger类是是操作wifi的核心类
WifiManager定义wifi各种状态、wifi Action、网络配置等
[java] view plain copy public class WifiManager { ..... public WifiManager(IWifiManager service, Handler handler) { mService = service; mHandler = handler; } ...... } 从IWifiManager 可知道，它是通过远程调用，也就是基于RPC原理（有时间再总结一下）。 为了保证Settings和Wifi相互交互，注册相应的监听对象。
[java] view plain copy public class WifiSettings extends SettingsPreferenceFragment implements DialogInterface.OnClickListener { ...... private WifiManager.ActionListener mConnectListener;//连接 private WifiManager.ActionListener mSaveListener;//保存 private WifiManager.ActionListener mForgetListener;//清除保存 ...... //继承SettingsPreferenceFragment并从写 onActivityCreated方法 @Override public void onActivityCreated(Bundle savedInstanceState) { // We don't call super.onActivityCreated() here, since it assumes we already set up // Preference (probably in onCreate()), while WifiSettings exceptionally set it up in // this method. mP2pSupported = getPackageManager().hasSystemFeature(PackageManager.FEATURE_WIFI_DIRECT); mWifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE); mChannel = mWifiManager.initialize(getActivity(), getActivity().getMainLooper(), null); mConnectListener = new WifiManager.ActionListener() { public void onSuccess() {//连接成功 } public void onFailure(int reason) {//连接失败 Toast.makeText(getActivity(), R.string.wifi_failed_connect_message, Toast.LENGTH_SHORT).show(); } }; mSaveListener = new WifiManager.ActionListener() { public void onSuccess() {//保存成功 } public void onFailure(int reason) {//保存失败 Toast.makeText(getActivity(), R.string.wifi_failed_save_message, Toast.LENGTH_SHORT).show(); } }; mForgetListener = new WifiManager.ActionListener() { public void onSuccess() {//清除保存成功 } public void onFailure(int reason) {//清除保存失败 Toast.makeText(getActivity(), R.string.wifi_failed_forget_message, Toast.LENGTH_SHORT).show(); } }; if (savedInstanceState != null && savedInstanceState.containsKey(SAVE_DIALOG_ACCESS_POINT_STATE)) { mDlgEdit = savedInstanceState.getBoolean(SAVE_DIALOG_EDIT_MODE); mAccessPointSavedState = savedInstanceState.getBundle(SAVE_DIALOG_ACCESS_POINT_STATE); } final Activity activity = getActivity(); final Intent intent = activity.getIntent(); // first if we're supposed to finish once we have a connection mAutoFinishOnConnection = intent.getBooleanExtra(EXTRA_AUTO_FINISH_ON_CONNECT, false); if (mAutoFinishOnConnection) { // Hide the next button if (hasNextButton()) { getNextButton().setVisibility(View.GONE); } final ConnectivityManager connectivity = (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivity != null && connectivity.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnected()) { activity.finish(); return; } } // if we're supposed to enable/disable the Next button based on our current connection // state, start it off in the right state mEnableNextOnConnection = intent.getBooleanExtra(EXTRA_ENABLE_NEXT_ON_CONNECT, false); if (mEnableNextOnConnection) { if (hasNextButton()) { final ConnectivityManager connectivity = (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivity != null) { NetworkInfo info = connectivity.getNetworkInfo( ConnectivityManager.TYPE_WIFI); changeNextButtonState(info.isConnected()); } } } addPreferencesFromResource(R.xml.wifi_settings);//加载布局 if (mSetupWizardMode) { getView().setSystemUiVisibility( View.STATUS_BAR_DISABLE_BACK | View.STATUS_BAR_DISABLE_HOME | View.STATUS_BAR_DISABLE_RECENT | View.STATUS_BAR_DISABLE_NOTIFICATION_ALERTS | View.STATUS_BAR_DISABLE_CLOCK); } // On/off switch is hidden for Setup Wizard if (!mSetupWizardMode) { Switch actionBarSwitch = new Switch(activity); if (activity instanceof PreferenceActivity) { PreferenceActivity preferenceActivity = (PreferenceActivity) activity; if (preferenceActivity.onIsHidingHeaders() || !preferenceActivity.onIsMultiPane()) { final int padding = activity.getResources().getDimensionPixelSize( R.dimen.action_bar_switch_padding); actionBarSwitch.setPadding(0, 0, padding, 0); activity.getActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM, ActionBar.DISPLAY_SHOW_CUSTOM); activity.getActionBar().setCustomView(actionBarSwitch, new ActionBar.LayoutParams( ActionBar.LayoutParams.WRAP_CONTENT, ActionBar.LayoutParams.WRAP_CONTENT, Gravity.CENTER_VERTICAL | Gravity.RIGHT)); } } mWifiEnabler = new WifiEnabler(activity, actionBarSwitch); } mEmptyView = (TextView) getView().findViewById(android.R.id.empty); getListView().setEmptyView(mEmptyView); if (!mSetupWizardMode) { registerForContextMenu(getListView()); } setHasOptionsMenu(true); // After confirming PreferenceScreen is available, we call super. super.onActivityCreated(savedInstanceState); } ...... }
三、用户on/off交互 用户通过Switch 开关按钮进行对wifi打开和关闭
[java] view plain copy public class WifiSettings extends SettingsPreferenceFragment implements DialogInterface.OnClickListener { ...... public void onActivityCreated(Bundle savedInstanceState) { ...... // On/off switch is hidden for Setup Wizard if (!mSetupWizardMode) { Switch actionBarSwitch = new Switch(activity); if (activity instanceof PreferenceActivity) { PreferenceActivity preferenceActivity = (PreferenceActivity) activity; if (preferenceActivity.onIsHidingHeaders() || !preferenceActivity.onIsMultiPane()) { final int padding = activity.getResources().getDimensionPixelSize( R.dimen.action_bar_switch_padding); actionBarSwitch.setPadding(0, 0, padding, 0); activity.getActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM, ActionBar.DISPLAY_SHOW_CUSTOM); activity.getActionBar().setCustomView(actionBarSwitch, new ActionBar.LayoutParams( ActionBar.LayoutParams.WRAP_CONTENT, ActionBar.LayoutParams.WRAP_CONTENT, Gravity.CENTER_VERTICAL | Gravity.RIGHT)); } } mWifiEnabler = new WifiEnabler(activity, actionBarSwitch);//将actionBarSwitch传递给WifiEnabler } ...... } ...... } WifiEnabler接受一个Switch对象和，并该对象进行操作 我们可以看下WifiEnabler这个类
[java] view plain copy import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.net.NetworkInfo; import android.net.wifi.SupplicantState; import android.net.wifi.WifiInfo; import android.net.wifi.WifiManager; import android.provider.Settings; import android.widget.CompoundButton; import android.widget.Switch; import android.widget.Toast; import com.android.settings.R; import com.android.settings.WirelessSettings; import java.util.concurrent.atomic.AtomicBoolean; public class WifiEnabler implements CompoundButton.OnCheckedChangeListener { private final Context mContext; private Switch mSwitch; private AtomicBoolean mConnected = new AtomicBoolean(false); private final WifiManager mWifiManager; private boolean mStateMachineEvent; private final IntentFilter mIntentFilter; private final BroadcastReceiver mReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (WifiManager.WIFI_STATE_CHANGED_ACTION.equals(action)) { handleWifiStateChanged(intent.getIntExtra( WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN)); } else if (WifiManager.SUPPLICANT_STATE_CHANGED_ACTION.equals(action)) { if (!mConnected.get()) { handleStateChanged(WifiInfo.getDetailedStateOf((SupplicantState) intent.getParcelableExtra(WifiManager.EXTRA_NEW_STATE))); } } else if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(action)) { NetworkInfo info = (NetworkInfo) intent.getParcelableExtra( WifiManager.EXTRA_NETWORK_INFO); mConnected.set(info.isConnected()); handleStateChanged(info.getDetailedState()); } } }; public WifiEnabler(Context context, Switch switch_) { mContext = context; mSwitch = switch_; mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE); mIntentFilter = new IntentFilter(WifiManager.WIFI_STATE_CHANGED_ACTION); // The order matters! We really should not depend on this. :( mIntentFilter.addAction(WifiManager.SUPPLICANT_STATE_CHANGED_ACTION); mIntentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION); } public void resume() { // Wi-Fi state is sticky, so just let the receiver update UI mContext.registerReceiver(mReceiver, mIntentFilter); mSwitch.setOnCheckedChangeListener(this); } public void pause() { mContext.unregisterReceiver(mReceiver); mSwitch.setOnCheckedChangeListener(null); } public void setSwitch(Switch switch_) { if (mSwitch == switch_) return; mSwitch.setOnCheckedChangeListener(null); mSwitch = switch_; mSwitch.setOnCheckedChangeListener(this); final int wifiState = mWifiManager.getWifiState(); boolean isEnabled = wifiState == WifiManager.WIFI_STATE_ENABLED; boolean isDisabled = wifiState == WifiManager.WIFI_STATE_DISABLED; mSwitch.setChecked(isEnabled); mSwitch.setEnabled(isEnabled || isDisabled); } public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { //Do nothing if called as a result of a state machine event if (mStateMachineEvent) { return; } // Show toast message if Wi-Fi is not allowed in airplane mode if (isChecked && !WirelessSettings.isRadioAllowed(mContext, Settings.System.RADIO_WIFI)) { Toast.makeText(mContext, R.string.wifi_in_airplane_mode, Toast.LENGTH_SHORT).show(); // Reset switch to off. No infinite check/listenenr loop. buttonView.setChecked(false); } // Disable tethering if enabling Wifi int wifiApState = mWifiManager.getWifiApState(); if (isChecked && ((wifiApState == WifiManager.WIFI_AP_STATE_ENABLING) || (wifiApState == WifiManager.WIFI_AP_STATE_ENABLED))) { mWifiManager.setWifiApEnabled(null, false); } if (mWifiManager.setWifiEnabled(isChecked)) { // Intent has been taken into account, disable until new state is active mSwitch.setEnabled(false); } else { // Error Toast.makeText(mContext, R.string.wifi_error, Toast.LENGTH_SHORT).show(); } } private void handleWifiStateChanged(int state) { switch (state) { case WifiManager.WIFI_STATE_ENABLING: mSwitch.setEnabled(false); break; case WifiManager.WIFI_STATE_ENABLED: setSwitchChecked(true); mSwitch.setEnabled(true); break; case WifiManager.WIFI_STATE_DISABLING: mSwitch.setEnabled(false); break; case WifiManager.WIFI_STATE_DISABLED: setSwitchChecked(false); mSwitch.setEnabled(true); break; default: setSwitchChecked(false); mSwitch.setEnabled(true); break; } } private void setSwitchChecked(boolean checked) { if (checked != mSwitch.isChecked()) { mStateMachineEvent = true; mSwitch.setChecked(checked); mStateMachineEvent = false; } } private void handleStateChanged(@SuppressWarnings("unused") NetworkInfo.DetailedState state) { // After the refactoring from a CheckBoxPreference to a Switch, this method is useless since // there is nowhere to display a summary. // This code is kept in case a future change re-introduces an associated text. /* // WifiInfo is valid if and only if Wi-Fi is enabled. // Here we use the state of the switch as an optimization. if (state != null && mSwitch.isChecked()) { WifiInfo info = mWifiManager.getConnectionInfo(); if (info != null) { //setSummary(Summary.get(mContext, info.getSSID(), state)); } } */ } } WifiEnabler实现了CompoundButton.OnCheckedChangeListener接口类，可见它也是一个监听器，并且在构造函数中通过接受一个switch对象去观察switch状态。
