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我正在編寫一個Android應用程序。在我的應用程序中，我希望它掃描WiFi網絡，然後通過檢查SSID連接到專用接入點（AP）。然後連接到AP後，建立一個TCP連接。Android：如何掃描WiFi，連接到AP然後建立TCP連接？
上面我按順序描述了3個任務。我知道如何獨立完成每項任務，但我不知道按順序完成它們的正確方法。例子表示讚賞。
目前我的代碼是開始掃描WiFi網絡每當用戶按下的按鈕的條件：
WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if (wifiManager.isWifiEnabled() == false) {
wifiManager.setWifiEnabled(true);
Toast.makeText(MainActivity.this, "WiFi is enabled", Toast.LENGTH_SHORT).show();
}
wifiManager.startScan();
我使用的廣播接收機，以檢查當掃描完成，然後調用一個方法（ReconnectAP()）至將WiFi連接到AP。我也使用廣播接收機來檢查它何時連接到AP，然後我想執行異步任務來建立TCP網絡。但是，通過使用Google搜索，我發現在廣播接收器中執行異步任務是一種糟糕的做法，因爲在接收器完成時異步任務可能會被Android終止。
private String networkSSID = "The_AP_SSID";
// In onCreate of MainActivity, register the broadcast receiver:
registerReceiver(WiFireceiver, new IntentFilter(
WifiManager.NETWORK_STATE_CHANGED_ACTION));
registerReceiver(WiFireceiver, new IntentFilter(
WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
// Implement my broadcast receiver class:
BroadcastReceiver WiFireceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(action)) {
Log.d(TAG, "WiFiReceiver received broadcast, action is SCAN_RESULTS_AVAILABLE_ACTION");
Log.d(TAG, "Start to check if need to reconnect to Charger AP");
ReconnectAP();
}
if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(action)) {
Log.d(TAG, "WiFiReceiver received broadcast, action is NETWORK_STATE_CHANGED_ACTION");
NetworkInfo netInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
// If the connection type is WiFi...
if (netInfo != null && ConnectivityManager.TYPE_WIFI == netInfo.getType()) {
// If it is connected now....
if (netInfo.isConnected()) {
Log.d(TAG, "WiFi connected");
// Get WiFi connection information, eg SSID
WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
String ssid = wifiInfo.getSSID();
Log.d(TAG, "WiFi connected SSID is : " + ssid);
if(ssid.equals(networkSSID)) {
// Start async task to establish a TCP connection:
new ConnectTCPAsynTask().execute();
}
} else {
Log.d(TAG, "WiFi disconnected");
}
}
}
}
};
int ReconnectAP() {
Log.d(TAG, "In ReconnectAP()");
wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
String ssid = wifiInfo.getSSID();
Log.d(TAG, "Original connected AP SSID: " + ssid);
if (!ssid.equals(networkSSID)) {
Log.d(TAG, "It is not equal to the dedicated AP SSID,
we will disconnect the current WiFi connection,
and then connect to our dedicate AP");
List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
for (WifiConfiguration i : list) {
if (i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"")) {
Log.d(TAG, "Start disconnect and reconnect to " + networkSSID);
wifiManager.disconnect();
wifiManager.enableNetwork(i.networkId, true);
wifiManager.reconnect();
return 1;
}
}
Log.d(TAG,"Reach here if cannot find the target SSID");
return -1;
}
Log.d(TAG, "Reach here if we already connected to the dedicated AP");
return 0;
}