我正在尝试制作一个可以创建可用wifi接入点列表的应用。这是我使用的部分代码:
x = new BroadcastReceiver()
{
@Override
public void onReceive(Context c, Intent intent)
{
results = wifi.getScanResults();
size = results.size();
if (results != null) {
for (int i=0; i<size; i++){
ScanResult scanresult = wifi.getScanResults().get(i);
String ssid = scanresult.SSID;
int rssi = scanresult.level;
String rssiString = String.valueOf(rssi);
textStatus.append(ssid + "," + rssiString);
textStatus.append("\n");
}
unregisterReceiver(x); //stops the continuous scan
textState.setText("Scanning complete!");
} else {
unregisterReceiver(x);
textState.setText("Nothing is found. Please make sure you are under any wifi coverage");
}
}
};
textStatus和textState都是TextView。我可以使它工作,但有时结果在一次扫描中显示重复的SSID,但信号电平不同。可能会有3-4个相同的SSID,但信号电平不同。
SSID真的不同吗?它们有什么不同?谁能解释?
您是否有多个路由器调制解调器用于同一网络?例如:一家公司的无线网络很大,在多个地方都安装了多个路由器调制解调器,因此每个房间都有Wifi。如果进行该扫描,则将获得具有相同SSID但具有不同acces点(因此信号电平也不同)的很多结果。
编辑:根据Walt的评论,如果您的调制解调器是双频的,即使只有一个接入点,您也可以得到多种结果。
使用下面的代码删除信号强度最高的重复ssid
public void onReceive(Context c, Intent intent) {
ArrayList<ScanResult> mItems = new ArrayList<>();
List<ScanResult> results = wifiManager.getScanResults();
wifiListAdapter = new WifiListAdapter(ConnectToInternetActivity.this, mItems);
lv.setAdapter(wifiListAdapter);
int size = results.size();
HashMap<String, Integer> signalStrength = new HashMap<String, Integer>();
try {
for (int i = 0; i < size; i++) {
ScanResult result = results.get(i);
if (!result.SSID.isEmpty()) {
String key = result.SSID + " "
+ result.capabilities;
if (!signalStrength.containsKey(key)) {
signalStrength.put(key, i);
mItems.add(result);
wifiListAdapter.notifyDataSetChanged();
} else {
int position = signalStrength.get(key);
ScanResult updateItem = mItems.get(position);
if (calculateSignalStength(wifiManager, updateItem.level) >
calculateSignalStength(wifiManager, result.level)) {
mItems.set(position, updateItem);
wifiListAdapter.notifyDataSetChanged();
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
这是我简单的解决方案,对我来说很有效
private void scanWifiListNew() {
wifiManager.startScan();
List<ScanResult> wifiList = wifiManager.getScanResults();
mWiFiList = new ArrayList<>();
for(ScanResult result: wifiList){
checkItemExists(mWiFiList, result);
}
setAdapter(mWiFiList);
}
private void printList(List<ScanResult> list){
for(ScanResult result: list){
int level = WifiManager.calculateSignalLevel(result.level, 100);
System.out.println(result.SSID + " Level is " + level + " out of 100");
}
}
private void checkItemExists(List<ScanResult> newWiFiList, ScanResult resultNew){
int indexToRemove = -1;
if(newWiFiList.size() > 0) {
for (int i = 0; i < newWiFiList.size(); i++) {
ScanResult resultCurrent = newWiFiList.get(i);
if (resultCurrent.SSID.equals(resultNew.SSID)) {
int levelCurrent = WifiManager.calculateSignalLevel(resultCurrent.level, 100);
int levelNew = WifiManager.calculateSignalLevel(resultNew.level, 100);
if (levelNew > levelCurrent) {
indexToRemove = i;
break;
}else indexToRemove = -2;
}
}
if(indexToRemove > -1){
newWiFiList.remove(indexToRemove);
newWiFiList.add(indexToRemove,resultNew);
}else if(indexToRemove == -1)newWiFiList.add(resultNew);
} else newWiFiList.add(resultNew);
}
private void setAdapter(List<ScanResult> list) {
listAdapter = new WifiListAdapter(getActivity().getApplicationContext(), list);
wifiListView.setAdapter(listAdapter);
}