1. You need to add permissions in AndroidManifest.xml
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
Depending on the android system, you also need to add and apply for location permissions
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
Otherwise, wifiManager.getScanResults() cannot get any data;
2. Please set the android settings to enable WLAN
private void startScanWifi() {
WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
wifiManager.startScan();
List<ScanResult> resultList = wifiManager.getScanResults();
ScanResult scanResult;
String SSID;
int rssi;
int level;
if (resultList != null && resultList.size() > 0) {
for (int i = 0; i < resultList.size(); i++) {
scanResult = resultList.get(i);
//name
SSID = scanResult.SSID;
//Signal strength, the obtained value is an interval value from 0 to -100, which is an int type data
rssi = scanResult.level;
//Signal strength level, according to the strength value, divided into 6 levels, 5 is the largest, indicating the highest strength
level = WifiManager.calculateSignalLevel(rssi, 6);
}
}
}
resultList is the result of the wifi list that can be connected
3. Obtain the connected wifi
private WifiResultInfo getConnectedWifi() {
WifiResultInfo wifiResultInfo = null;
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
if (wifiInfo != null) {
String ssid = wifiInfo.getSSID();
int rssi = wifiInfo.getRssi();
if(ssid.startsWith("\"") && ssid.endsWith("\""))
{
ssid = ssid.substring(1, ssid.length() - 1);
}
}
return wifiResultInfo;
}