检查startScan是否成功

Question

我想检查方法wifiManager.startScan（）是否已经成功进行AP扫描。如果启动已经开始，则此方法返回true，但如果扫描已成功则返回。事实上，即使wifiManager.startScan（）返回true，我有时也会收到LogCat中的“无法启动AP扫描”消息...因此，如果我在logcat中有此消息，该如何重新启动新扫描？

这是我当前的代码部分：

while(wifiManager.startScan()==false){ 
wifiManager.startScan(); 
} 

PS：

我的广播接收器的全码：

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; 
     } 

} 

Answer 1

你在做什么是每个周期开始扫描两次你的循环。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，您可能会阻止UI线程。 此外，startScan返回true并不表示任何新的扫描结果都可用。 为此，您必须为WifiManager.SCAN_RESULTS_AVAILABLE_ACTION注册BroadcastReceiver。