wifi的開啓 掃描 獲取以連接過的wifi配置

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    tools:context="com.example.wifi.MainActivity">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="開啓wifi"
        android:onClick="click1"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="獲取掃描信息"
        android:onClick="click2"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="獲取已經配置過的信息"
        android:onClick="click3"/>

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/lv">

    </ListView>

</LinearLayout>

package com.example.wifi;

import android.Manifest;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiManager;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

import static android.R.layout.simple_list_item_1;

public class MainActivity extends AppCompatActivity {
    WifiManager wifiManager;
    ListView lv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 找到ListView控件
        lv = (ListView) findViewById(R.id.lv);
        // 獲取WifiManager實例(要用全局上下文去獲取系統wifi服務)
        wifiManager = (WifiManager) getApplicationContext().getSystemService(WIFI_SERVICE);
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                // 拿到我當前選的wifi的信息
                final ScanResult scanResult = scanResults.get(position);
                // 設置一個自定義的密碼輸入對話框
                AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
                builder.setTitle("連接wifi");
                // 創建文本輸入控件
                final EditText et = new EditText(MainActivity.this);
                et.setHint("請輸入密碼");
                // 把控件設置到對話框裏
                builder.setView(et);
                // 給對話框設置取消按鈕監聽
                builder.setNegativeButton("取消",null);
                // 給對話框設置確定按鈕監聽
                builder.setPositiveButton("確定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // 創建wifi的配置實例
                        WifiConfiguration config = new WifiConfiguration();
                        // 獲取用戶輸入的密碼
                        String password = et.getText().toString();
                        config.SSID = "\"" + scanResult.SSID + "\"";
                        config.preSharedKey = "\"" + password + "\"";
                        config.hiddenSSID = true;
                        config.allowedAuthAlgorithms
                                .set(WifiConfiguration.AuthAlgorithm.OPEN);
                        config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
                        config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
                        config.allowedPairwiseCiphers
                                .set(WifiConfiguration.PairwiseCipher.TKIP);
                        // config.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
                        config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
                        config.allowedPairwiseCiphers
                                .set(WifiConfiguration.PairwiseCipher.CCMP);
                        config.status = WifiConfiguration.Status.ENABLED;
                        int networkId = wifiManager.addNetwork(config);
                        wifiManager.enableNetwork(networkId, true);
                    }
                }).create().show();
            }
        });
    }

    // 開啓wifi的按鈕監聽
    public void click1(View view){
        // WifiManager可以直接操作wifi
        // 這裏要添加wifi改變狀態的權限<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
        wifiManager.setWifiEnabled(true);
    }

    // 獲取掃描信息按鈕的監聽
    public void click2(View view){
        // 獲取所有掃描的熱點信息，先確定權限，android6.0(API 23)及以上系統就需要動態添加地理位置的權限，否則不需要
        if (Build.VERSION.SDK_INT > 23) {
            // 添加地理位置的權限
            int check = checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION);
            // 判斷是否已經有權限
            if (check == PackageManager.PERMISSION_GRANTED) {
                // 直接執行掃描代碼
                getScanResult();
            }else{
                // 請求用戶手動打開權限（String數組是有可能需要打開多個權限，requestCode有可能多個地方需要請求權限）
                requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},20);
            }
        }else{
            // 有權限就執行，或者低於6.0
            getScanResult();
        }
    }

    // 重寫onRequestPermissionsResult方法來確定用戶是否選擇允許權限
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        // 回調判斷用戶點擊的是允許還是拒絕
        if (requestCode == 20 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
            // 允許執行掃描
            getScanResult();
        }else{
            // 拒絕就重新獲取或者退出程序（這裏就Toast下）
            Toast.makeText(this, "沒有請求到權限，無法訪問wifi", Toast.LENGTH_SHORT).show();
        }
    }

    List<ScanResult> scanResults;
    private void getScanResult(){
        // wifi管理者調用獲取掃描的方法,同時也需要添加ACCESS_WIFI_STATE權限
        scanResults = wifiManager.getScanResults();
        // 創建一個集合裝掃描出的數據
        List<String> list = new ArrayList<>();
        // 用foreach方法把數據添加到集合裏
        for (ScanResult scanResult:scanResults) {
            // 添加wifi的名稱 MAC地址 加密方式 wifi的水平（信號強度）
            list.add(scanResult.SSID+"\n"+scanResult.BSSID+"\n"+scanResult.capabilities+"\n"+scanResult.level);
/*            // 添加wifi的名稱
            list.add(scanResult.SSID);
            // 添加wifi的MAC地址
            list.add(scanResult.BSSID);
            // 添加wifi的加密方式
            list.add(scanResult.capabilities);
            // 添加wifi的水平（信號強度）
            list.add(String.valueOf(scanResult.level));*/
        }
        Log.e("TAG", "-------------"+list.toString());
        // 創建一個適配器
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, simple_list_item_1,list);
        // ListView設置適配器
        lv.setAdapter(adapter);
    }

    String item;
    // 獲取已經配置過的信息按鈕的監聽
    public void click3(View view){
        List<WifiConfiguration> configuradNetworks = wifiManager.getConfiguredNetworks();
        final List<String> list = new ArrayList<>();
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("連接過的wifi");
        final ListView listView = new ListView(this);
        builder.setView(listView);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,list);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                TextView tv = (TextView)view;
                item = (String) tv.getText();
            }
        });
        for (WifiConfiguration configuradNetwork : configuradNetworks) {
            list.add("名稱："+configuradNetwork.SSID+"\nID:"+configuradNetwork.networkId+"\n"+configuradNetwork.FQDN);
        }
        builder.setNegativeButton("取消",null);
        builder.setPositiveButton("確定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Toast.makeText(MainActivity.this, "選擇了"+ item, Toast.LENGTH_SHORT).show();
            }
        }).create().show();
    }
}

要記得加權限

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />