我想检查wifiManager.startScan（）方法是否有效成功进行AP扫描。如果开始已开始，则此方法返回true，但如果扫描成功则不返回。实际上，即使wifiManager.startScan（）返回true，我有时也会在LogCat中收到“无法启动AP扫描”的消息...那么当我在logcat中收到此消息时，如何重新启动新扫描？
这是我当前代码的一部分：
while(wifiManager.startScan()==false){
wifiManager.startScan();
}
P.S：
我的BroadcastReceiver的完整代码：
package paquet.wifiview2;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.util.Log;
import android.widget.Toast;
import java.util.List;
import android.annotation.SuppressLint;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
public class WifiBroadcastReceiver extends BroadcastReceiver {
private WifiManager wifiManager;
private WifiAdapter wifiAdapter;
private List<WifiItem> listeWifiItem;
private int position=0;
private boolean start=true;
private int numberdisplay=4;
private float[][] valueRSSI = new float[5][10];
private String[] macAdress = new String[5];
private int[] sampleposition = new int[5];
private String[] sSID = new String[5];
private int totalsample=50;
private boolean copy=false;
private static boolean broadcastFinish=true;
//private boolean scanStart=false;
@SuppressLint("ShowToast")
@Override
public void onReceive(Context context, Intent intent) {
macAdress[0]="5c:0e:8b:26:d7:72";
macAdress[1]="5c:0e:8b:26:d7:70";
macAdress[2]="00:16:9c:92:04:30";
macAdress[3]="00:1c:df:7f:6b:85";
macAdress[4]="5c:0e:8b:21:81:12";
Log.d("info3","broadcastFinish (Receiver) : " + broadcastFinish);
wifiManager = ((WifiActivity) context).getCurrentWifiManager();
wifiAdapter = ((WifiActivity) context).getWifiAdapter();
listeWifiItem = ((WifiActivity) context).getListeWifiItem();
if(position>numberdisplay){position=0;}
// Check if the object is well instantiated
if (wifiManager != null) {
// Check if wifi is turned on
if (wifiManager.isWifiEnabled()) {
List<ScanResult> listeScan = wifiManager.getScanResults();// Getting the scan
if (sampleposition[numberdisplay-1]==totalsample || start==true){ //If the number of samples is equal to the wished number
// For each scan
if(start==false && position<=numberdisplay-1){ // If you don't initialize and if you haven't real all the AP
if(position == 0){copy=true;listeWifiItem.clear();} // If you start to read your list, you have to delete your old list before
if(copy==true){ //If you start to read your list effectively
while(position<=numberdisplay-1){ // While you haven't read all the AP.
if(sampleposition[position]!=0 && (position == 0 || macAdress[position]!=macAdress[0] && macAdress[position]!=macAdress[position-1])){
//If the sample quantity of a position isn't null and if you haven't copy the concerned mac address
for(int i=0;i<=1;i++){
WifiItem item = new WifiItem();
item.setAdresseMac(macAdress[position]);
if(i==1){item.setAPName("old : " + sSID[position]);} else{item.setAPName(sSID[position]);}
item.setForceSignal((valueRSSI[position][i])/(sampleposition[position]));
Log.d("Info1",sSID[position] + " | macAdress[" + position + "] : " + macAdress[position] + " - RSSI : " + (valueRSSI[position][i])/(sampleposition[position]) + " dBm - echantillons : " + (sampleposition[position]));
listeWifiItem.add(item);
}
}
sampleposition[position]=0; //réinitialisation du nombre d'échantillon par position
position++;//Incrementation of the readed position
}
}
}
else{ //Initialization of WifiItem
while(position<=numberdisplay-1) { //You read all the scanned AP
for(int i=0;i<=1;i++){
WifiItem item = new WifiItem();
item.setAdresseMac("00:00:00:00:00");
item.setAPName("Initalisation");
if (start == true){item.setForceSignal(1);} //Si on initalise bien, on affiche juste 1
listeWifiItem.add(item);
}
for(int i=0;i<=9;i++){valueRSSI[position][i]=0;}//réinitialisation de la RSSI par position
sampleposition[position]=0;//réinitialisation du nombre d'échantillon par position
position++;//Incrémentation de la position lue
}
}
if(position==numberdisplay){start=false;position=0;} //If you have exceed the wanted number of displayed points, you go back to 0 and don't start.
// Refreshing of the list
copy=false;
wifiAdapter.notifyDataSetChanged();
}
else {
if(position <=numberdisplay-1){ //If you haven't exceed the wanted number of positions
for (ScanResult scanResult : listeScan) {
broadcastFinish = false;
if(sampleposition[position]==0){ //If you haven't start to sample
if(macAdress[position].equals(scanResult.BSSID)){ //Initialisation réelle des valeurs des positions
for(int i=9;i>=1;i--){valueRSSI[position][i] = valueRSSI[position][i-1];} //Saving the old values of the RSSI average
valueRSSI[position][0] = scanResult.level; //Starting to make a new average of 50 samples
sSID[position] = scanResult.SSID;
Log.d("WifiActivity", scanResult.SSID + " MAC : " + scanResult.BSSID + " LEVEL " + scanResult.level + " | macadress : " + macAdress[position] );
if(valueRSSI[position][0]!=0){sampleposition[position]++;}
break;
}
}
else{
if(macAdress[position].equals(scanResult.BSSID) && sampleposition[position]<=totalsample){
valueRSSI[position][0] = valueRSSI[position][0] + scanResult.level;
Log.d("WifiActivity", scanResult.SSID + " MAC : " + scanResult.BSSID + " LEVEL " + scanResult.level + " | macadress : " + macAdress[position] );
sampleposition[position]++;
break;
}
}
}
broadcastFinish = true;
}
if(sampleposition[position]>=totalsample){position++;}
}
}
}
else {
Toast.makeText(context, "Vous devez activer votre WiFi", Toast.LENGTH_SHORT);
}
}
public static boolean getBroadcastFinish() {
return broadcastFinish;
}
}
答案 0 :(得分：0)
您正在做的是在每个循环周期开始扫描两次。我想你想要的是：
boolean success = false;
while(success == false){
success = wifiManager.startScan();
}
请注意，如果您不在后台线程中执行此代码，则可能会阻止UI线程。
此外，startScan返回true并不表示任何新的扫描结果可用。
为此，您必须为BroadcastReceiver注册WifiManager.SCAN_RESULTS_AVAILABLE_ACTION。