以程式設計方式掃描 Android WiFi 網路
本示例演示如何以程式設計方式掃描 WiFi 網路。
步驟 1 − 在 Android Studio 中新建一個專案,選擇 File ⇒ New Project,然後填寫所有必需的詳細資訊來新建一個專案。
步驟 2 − 在 res/layout/activity_main.xml 中新增以下程式碼。
<?xml version = "1.0" encoding = "utf-8"?> <RelativeLayout xmlns:android = "http://schemas.android.com/apk/res/android" xmlns:tools = "http://schemas.android.com/tools" android:layout_width = "match_parent" android:layout_height = "match_parent" android:layout_margin = "16dp" android:orientation = "vertical" tools:context = ".MainActivity"> <ListView android:id = "@+id/wifiList" android:layout_width = "match_parent" android:layout_height = "match_parent" android:layout_above = "@+id/scanBtn" /> <Button android:id = "@+id/scanBtn" android:layout_width = "match_parent" android:layout_height = "50dp" android:layout_alignParentBottom = "true" android:layout_gravity = "bottom" android:layout_margin = "15dp" android:text = "Scan WiFi" /> </RelativeLayout>
步驟 3 − 在 src/MainActivity.java 中新增以下程式碼
package com.example.myapplication; import android.Manifest; import android.content.Context; import android.content.IntentFilter; import android.content.pm.PackageManager; import android.net.wifi.WifiManager; import android.os.Build; import android.support.annotation.NonNull; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.ListView; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private ListView wifiList; private WifiManager wifiManager; private final int MY_PERMISSIONS_ACCESS_COARSE_LOCATION = 1; WifiReceiver receiverWifi; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); wifiList = findViewById(R.id.wifiList); Button buttonScan = findViewById(R.id.scanBtn); wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE); if (!wifiManager.isWifiEnabled()) { Toast.makeText(getApplicationContext(), "Turning WiFi ON...", Toast.LENGTH_LONG).show(); wifiManager.setWifiEnabled(true); } buttonScan.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) ! = PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions( MainActivity.this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, MY_PERMISSIONS_ACCESS_COARSE_LOCATION); } else { wifiManager.startScan(); } } }); } @Override protected void onPostResume() { super.onPostResume(); receiverWifi = new WifiReceiver(wifiManager, wifiList); IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION); registerReceiver(receiverWifi, intentFilter); getWifi(); } private void getWifi() { if (Build.VERSION.SDK_INT > = Build.VERSION_CODES.M) { Toast.makeText(MainActivity.this, "version> = marshmallow", Toast.LENGTH_SHORT).show(); if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) ! = PackageManager.PERMISSION_GRANTED) { Toast.makeText(MainActivity.this, "location turned off", Toast.LENGTH_SHORT).show(); ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, MY_PERMISSIONS_ACCESS_COARSE_LOCATION); } else { Toast.makeText(MainActivity.this, "location turned on", Toast.LENGTH_SHORT).show(); wifiManager.startScan(); } } else { Toast.makeText(MainActivity.this, "scanning", Toast.LENGTH_SHORT).show(); wifiManager.startScan(); } } @Override protected void onPause() { super.onPause(); unregisterReceiver(receiverWifi); } @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); switch (requestCode) { case MY_PERMISSIONS_ACCESS_COARSE_LOCATION: if (grantResults.length > 0 && grantResults[0] = = PackageManager.PERMISSION_GRANTED) { Toast.makeText(MainActivity.this, "permission granted", Toast.LENGTH_SHORT).show(); wifiManager.startScan(); } else { Toast.makeText(MainActivity.this, "permission not granted", Toast.LENGTH_SHORT).show(); return; } break; } } }
步驟 4 − 在 src/WifiReceiver 中新增以下程式碼
package com.example.myapplication; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.net.wifi.ScanResult; import android.net.wifi.WifiManager; import android.widget.ArrayAdapter; import android.widget.ListView; import android.widget.Toast; import java.util.ArrayList; import java.util.List; class WifiReceiver extends BroadcastReceiver { WifiManager wifiManager; StringBuilder sb; ListView wifiDeviceList; public WifiReceiver(WifiManager wifiManager, ListView wifiDeviceList) { this.wifiManager = wifiManager; this.wifiDeviceList = wifiDeviceList; } public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(action)) { sb = new StringBuilder(); List<ScanResult> wifiList = wifiManager.getScanResults(); ArrayList<String> deviceList = new ArrayList<>(); for (ScanResult scanResult : wifiList) { sb.append("
").append(scanResult.SSID).append(" - ").append(scanResult.capabilities); deviceList.add(scanResult.SSID + " - " + scanResult.capabilities); } Toast.makeText(context, sb, Toast.LENGTH_SHORT).show(); ArrayAdapter arrayAdapter = new ArrayAdapter(context, android.R.layout.simple_list_item_1, deviceList.toArray()); wifiDeviceList.setAdapter(arrayAdapter); } } }
步驟 5 − 在 androidManifest.xml 中新增以下程式碼
<?xml version = "1.0" encoding = "utf-8"?> <manifest xmlns:android = "http://schemas.android.com/apk/res/android" package = "com.example.myapplication"> <uses-permission android:name = "android.permission.ACCESS_COARSE_LOCATION" /> <uses-permission android:name = "android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name = "android.permission.CHANGE_WIFI_STATE" /> <application android:allowBackup = "true" android:icon = "@mipmap/ic_launcher" android:label = "@string/app_name" android:roundIcon = "@mipmap/ic_launcher_round" android:supportsRtl = "true" android:theme = "@style/AppTheme"> <activity android:name = "com.example.myapplication.MainActivity"> <intent-filter> <action android:name = "android.intent.action.MAIN" /> <category android:name = "android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
讓我們試著執行您的應用程式。我假設您已經將實際的 Android 移動裝置連線到您的計算機。為了從 Android Studio 執行該應用程式,請開啟您的其中一個專案的 activity 檔案,然後從工具欄中單擊執行 圖示。選擇您的移動裝置作為選項,然後檢查您的移動裝置,上面會顯示您的預設螢幕 –
單擊此處下載專案程式碼
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