我想搜索可用的wifi网络,并在我的应用程序中单击开始按钮时将其显示在列表中,但是我的代码无法找到任何wifi网络。我试图用TextView
或Toast
显示可用网络的数量,但始终显示0
。
这是我的代码:
public class MainActivity extends AppCompatActivity {
//Listview
private ArrayAdapter<String> adapter;
private ListView list;
private ArrayList<String> mylist = new ArrayList<String>();
ListAdapter adapter1;
TextView tV;
//Wifi
private WifiManager mywifi;
WifiReceiver myreceiver;
List<ScanResult> wifiList;
StringBuilder sb;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//definieren
Button start = (Button) findViewById(R.id.btnstart);
//Listview
list = (ListView) findViewById(R.id.lV);
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mylist);
list.setAdapter(adapter);
//Textview
tV = (TextView) findViewById(R.id.tV);
tV.setText("");
//Wifi
mywifi = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
if (mywifi.isWifiEnabled() == false) {
Toast.makeText(getApplicationContext(), "Wifi is disabled ....making it enabled", Toast.LENGTH_SHORT).show();
mywifi.setWifiEnabled(true);
}
myreceiver = new WifiReceiver();
registerReceiver(myreceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
mywifi.startScan();
//buttenevents
start.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//getWifiNetworksList();
}
});
}
public void getWifiNetworksList() {
tV.setText("Wifi is starting");
tV.setText(myreceiver.Wifilist());
}
class WifiReceiver extends BroadcastReceiver {
public String txt;
// This method call when number of wifi connections changed
public void onReceive(Context c, Intent intent) {
sb = new StringBuilder();
wifiList = mywifi.getScanResults();
sb.append("\n Number Of Wifi connections :" + wifiList.size() + "\n\n");
for (int i = 0; i < wifiList.size(); i++) {
sb.append(new Integer(i + 1).toString() + ". ");
sb.append((wifiList.get(i)).toString());
sb.append("\n\n");
}
tV.setText(sb);//tV...TextView
Toast.makeText(getApplicationContext(), "reciever finished", Toast.LENGTH_SHORT).show();
}
public String Wifilist() {
return txt;
}
}
}
该代码工作正常。在Nexus 5上进行了测试。我刚刚在清单文件中添加了以下权限
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
如果仍未显示任何结果。只需确保您的用户已允许您的应用使用位置权限即可。您可以通过两种方式执行此操作
手动
转到手机中的设置,然后点击该应用的启用选项。 (在我的情况下,我的应用程序名称为WifiSolution)。
以编程方式
您也可以使用Android Runtime Permission进行编程。