android Rwifi扫描Demo

以下是一个简单的Android WiFi扫描的Demo：

首先，在你的AndroidManifest.xml文件中添加以下权限：

<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_COARSE_LOCATION"/>

然后，创建一个名为WifiScanner的Activity，并在其布局文件中添加一个Button和一个TextView：

WifiScanner.java:

public class WifiScanner extends AppCompatActivity {

    private WifiManager wifiManager;
    private List<ScanResult> scanResults;
    private StringBuilder stringBuilder = new StringBuilder();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_wifi_scanner);

        wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);

        Button scanButton = findViewById(R.id.scanButton);
        scanButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                scanWifi();
            }
        });

        TextView wifiListTextView = findViewById(R.id.wifiListTextView);
        wifiListTextView.setMovementMethod(new ScrollingMovementMethod());
    }

    private void scanWifi() {
        stringBuilder = new StringBuilder();
        if (!wifiManager.isWifiEnabled()) {
            wifiManager.setWifiEnabled(true);
        }
        registerReceiver(wifiReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
        wifiManager.startScan();
        Toast.makeText(this, "Scanning WiFi ...", Toast.LENGTH_SHORT).show();
    }

    private final BroadcastReceiver wifiReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            scanResults = wifiManager.getScanResults();
            unregisterReceiver(this);
            for (ScanResult scanResult : scanResults) {
                stringBuilder.append("SSID: ")
                        .append(scanResult.SSID)
                        .append(" , BSSID: ")
                        .append(scanResult.BSSID)
                        .append(" , RSSI: ")
                        .append(scanResult.level)
                        .append("\n\n");
            }
            TextView wifiListTextView = findViewById(R.id.wifiListTextView);
            wifiListTextView.setText(stringBuilder.toString());
        }
    };
}

activity_wifi_scanner.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/scanButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="50dp"
        android:text="Scan WiFi"/>

    <TextView
        android:id="@+id/wifiListTextView"
        android:layout_below="@id/scanButton"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="10dp"
        android:textColor="#000000"
        android:textSize="18sp"
        android:scrollbars="vertical"/>

</RelativeLayout>

这个Demo中，我们使用了WifiManager来扫描WiFi网络。当用户点击“Scan WiFi”按钮时，我们将启动一个广播接收器来接收扫描结果。接收到结果后，我们将遍历所有的扫描结果，并将它们显示在TextView中。

请注意，WiFi扫描可能需要一些时间，具体取决于您的设备和周围的网络环境。因此，您应该在用户点击按钮后显示一个Toast消息，以提示他们正在进行WiFi扫描。