Android Wifi work station Framework and Architecture
Android Wifi work station Framework and Architecture
with wpa_supplicant 0.8.X, BCM4329.
转载请注明出处。
Settings/Wifi UI part structure
WifiSettings是主对话框
167
168 @Override
169 public void onActivityCreated(Bundle savedInstanceState) {
170 // We don't call super.onActivityCreated() here, since it assumes we already set up
171 // Preference (probably in onCreate()), while WifiSettings exceptionally set it up in
172 // this method.
173
174 mWifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
175 mWifiManager.asyncConnect(getActivity(), new WifiServiceHandler());
176 if (savedInstanceState != null
177 && savedInstanceState.containsKey(SAVE_DIALOG_ACCESS_POINT_STATE)) {
178 mDlgEdit = savedInstanceState.getBoolean(SAVE_DIALOG_EDIT_MODE);
179 mAccessPointSavedState = savedInstanceState.getBundle(SAVE_DIALOG_ACCESS_POINT_STATE);
180 }
1101 public void asyncConnect(Context srcContext, Handler srcHandler) {
1102 mAsyncChannel.connect(srcContext, srcHandler, getMessenger());
1103 }
establish a half connect between WifiManager and WifiService.
1117 public void connectNetwork(WifiConfiguration config) {
1118 if (config == null) {
1119 return;
1120 }
1121 mAsyncChannel.sendMessage(CMD_CONNECT_NETWORK, config);
1122 }
Activity创建的时候会建立和WifiService的AsyncChannel的连接，WifiService同样会建立一个AsyncChannelHandler来处理来自这个Channel的命令消息。AsyncChannel的所谓异步主要用来传递比较耗时的操作并把结果返回给原请求者。AsyncChannel两端分别有一个MessageHandler，srcHandler请求destHandler，destHandler把结果发回给srcHandler，主要是用于处理比较耗时的操作且在WifiManager中处理返回结果。
严格来说，在WifiService的Inte易做图ce方法之外再做出一个通道提供额外的方法并不是一个什么好的设计。命令是可以通过同步接口发送给WifiService的，但是WifiService的处理结果如果通过broadcast或intent给WifiManager，则又解耦的过度；如果WifiManager实现一个binder做event sink，又有点小题大做，所以这儿引入这么个AsyncChannel实在是不得以而为之。
WifiSettings界面使能Wifi时会使用定时器请求扫描，获取扫描结果，列出AP列表。Scanner使用定时器，周期性向WifiService请求主动扫描，定时原理是发出本次扫描请求后延迟1s发送下次请求。相关代码如下：
private class Scanner extends Handler {
private int mRetry = 0;
void resume() {
if (!hasMessages(0)) {
sendEmptyMessage(0);
}
}
void forceScan() {
removeMessages(0);
sendEmptyMessage(0);
}
void pause() {
mRetry = 0;
removeMessages(0);
}
@Override
public void handleMessage(Message message) {
if (mWifiManager.startScanActive()) {
mRetry = 0;
} else if (++mRetry >= 3) {
mRetry = 0;
Toast.makeText(getActivity(), R.string.wifi_fail_to_scan,
Toast.LENGTH_LONG).show();
return;
}
sendEmptyMessageDelayed(0, WIFI_RESCAN_INTERVAL_MS);
}
}
列出AP列表的代码如下：
In WifiSettings.java
final List<ScanResult> results = mWifiManager.getScanResults(); //同步操作
if (results != null) {
for (ScanResult result : results) {
// Ignore hidden and ad-hoc networks.
if (result.SSID == null || result.SSID.length() == 0 || result.capabilities.contains("[IBSS]")) {
continue;
}
boolean found = false;
for (AccessPoint accessPoint : apMap.getAll(result.SSID)) {
if (accessPoint.update(result))
found = true;
}
if (!found) {
AccessPoint accessPoint = new AccessPoint(getActivity(), result);
accessPoints.add(accessPoint);
apMap.put(accessPoint.ssid, accessPoint);
补充：移动开发 , Android ,
