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法學開發 Android 的 WiFi 掃描器
此示例演示如何為 Android 開發 WiFi 掃描器
步驟 1 − 在 Android Studio 中建立新專案，轉到“檔案 ⇒ 新專案”並填寫所有必需詳細資訊以建立一個新專案。
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>
讓我們嘗試執行你的應用程式。我假設你的實際 Android 移動裝置已連線到你的計算機。要從 Android Studio 執行應用程式，請開啟專案的某個活動檔案，然後單擊工具欄中的執行 
圖示。選擇你的移動裝置作為選項，然後檢查你的移動裝置，它將顯示你的預設螢幕 -
點選這裡下載專案程式碼
更新於： 2019 年 7 月 30 日
1 千次瀏覽
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