Android 7.1.1 又出幺蛾子了 —— 再谈 Android 上的 Wifi 连接

在之前的博客文章中,我写了点在 Android 6 系统中连接到指定名称的 Wifi 的体验.然而,在 Android 7 中,有一些东西又变化了.另外就是在那篇文章中我说要提供代码,结果拖到这篇文章,也没有提供.那么,请忽略那篇文章,来看看这篇吧.

不变

首先聊下 Android 6 到 Android 7之间没有变化的一些东西.想要让设备连接到指定名称的热点,那么一定要经历以下的几个过程:

1. 打开 Wifi
2. 包装出 WifiConfiguration 对象
3. 用 WifiConfiguration 对象获得 WifiManager 对象中 WifiConfiguration 的 index
4. 用 enableNetwork 连接网络
5. 使用完毕,断开网络然后删除创建出的配置文件
6. 关闭 Wifi

变

1. 在 Android 6 中,如果系统中已经存在了其他的 app 或者是由系统生成的热点信息,那么它将会返回 -1,而在 Android 7上并不是这个设定,是直接返回 index 的值
2. 在 Android 7 中,无法使用 removeNetwork 这个公开的方法删除一个已有的配置,虽然在删除后,在系统中显示已经被删除,但是当重新关闭再打开 Wifi 开关时,会发现被删除的配置由系统进行创建.这里,需要使用系统的隐藏方法 forget 进行删除

以上就是所有信息了.以下是代码:

package com.xxxxxxxx.wifitest7;

import android.content.Context;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private static final String TAG = "MainActivity";

    private final static String WIFI_SSID = "TP-LINK_ACA6";
    private Button mBtnOpenWifi;
    private Button mBtnCloseWifi;
    private Button mBtnAddWifi;
    private Button mBtnDelWifi;
    private Button mBtnConnect;
    private Button mBtnDisConnect;
    private TextView mTextViewShowResult;

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

        initUi();
    }

    private void initUi() {
        mBtnOpenWifi = (Button) findViewById(R.id.btnOpenWifi);
        mBtnOpenWifi.setOnClickListener(this);
        mBtnCloseWifi = (Button) findViewById(R.id.btnCloseWifi);
        mBtnCloseWifi.setOnClickListener(this);
        mBtnAddWifi = (Button) findViewById(R.id.btnAddWifi);
        mBtnAddWifi.setOnClickListener(this);
        mBtnDelWifi = (Button) findViewById(R.id.btnDelWifi) ;
        mBtnDelWifi.setOnClickListener(this);
        mBtnConnect = (Button) findViewById(R.id.btnConnect);
        mBtnConnect.setOnClickListener(this);
        mBtnDisConnect = (Button) findViewById(R.id.btnDisConnect);
        mBtnDisConnect.setOnClickListener(this);
        mTextViewShowResult = (TextView) findViewById(R.id.textViewShowResult);
    }

    @Override
    public void onClick(View view) {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        mTextViewShowResult.setText("");
        // "TP-LINK_ACA6"
        switch (view.getId()) {
            case R.id.btnOpenWifi:
                if (openWifi()) {
                    mTextViewShowResult.setText("正在打开 Wifi,请稍等");
                } else {
                    mTextViewShowResult.setText("打开 Wifi 失败,Wifi 已经开启?");
                }
                break;
            case R.id.btnCloseWifi:
                if (closeWifi()) {
                    mTextViewShowResult.setText("正在关闭 Wifi,请稍等");
                } else {
                    mTextViewShowResult.setText("关闭 Wifi 失败,Wifi 已经关闭?");
                }
                break;
            case R.id.btnAddWifi:
                int networkId = addWifiItem(WIFI_SSID);
                mTextViewShowResult.setText("得到的 Wifi 的 ID 是:" + networkId);
                break;
            case R.id.btnDelWifi:
                forgetConfiguration(this,createWifiConfiguration(WIFI_SSID));
                break;
            case R.id.btnConnect:
                connectToSpecSsid(addWifiItem(WIFI_SSID));
                break;
            case R.id.btnDisConnect:
                disableSpecSsid(addWifiItem(WIFI_SSID));
                break;
        }
    }

    public static WifiConfiguration createWifiConfiguration(String SSID) {
        WifiConfiguration wifiConfiguration = new WifiConfiguration();
        wifiConfiguration.allowedKeyManagement.clear();
        wifiConfiguration.allowedAuthAlgorithms.clear();
        wifiConfiguration.hiddenSSID = true;

        // 无密码
        wifiConfiguration.SSID = "\"" + SSID + "\"";
        wifiConfiguration.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);

        return wifiConfiguration;
    }

    private boolean openWifi() {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        boolean result = false;
        switch (wifiManager.getWifiState()) {
            case WifiManager.WIFI_STATE_DISABLED:
            case WifiManager.WIFI_STATE_DISABLING:
                wifiManager.setWifiEnabled(true);
                result = true;
                break;
            case WifiManager.WIFI_STATE_ENABLED:
            case WifiManager.WIFI_STATE_ENABLING:
                result = false;
                break;
        }
        return result;
    }

    private boolean closeWifi() {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        boolean result = false;
        switch (wifiManager.getWifiState()) {
            case WifiManager.WIFI_STATE_ENABLED:
            case WifiManager.WIFI_STATE_ENABLING:
                wifiManager.setWifiEnabled(false);
                result = true;
                break;
            case WifiManager.WIFI_STATE_DISABLED:
            case WifiManager.WIFI_STATE_DISABLING:
                result = false;
                break;
        }
        return result;
    }

    private int addWifiItem (String ssid) {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        List<WifiConfiguration> wifiConfigurations = wifiManager.getConfiguredNetworks();
        int networkId = -10;
        if (null != wifiConfigurations) {
            for (WifiConfiguration wifiConfiguration : wifiConfigurations) {
                if (wifiConfiguration.SSID.equals("\"" + ssid + "\"")) {
                    networkId = wifiConfiguration.networkId;
                    break;
                }
            }
        }

        if (networkId == -10) {
            networkId = wifiManager.addNetwork(createWifiConfiguration(ssid));
        }

        return networkId;
    }

    private boolean delWifiItem (String ssid) {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        List<WifiConfiguration> wifiConfigurations = wifiManager.getConfiguredNetworks();
        boolean result = false;
        int networkId = -10;
        if (null != wifiConfigurations) {
            for (WifiConfiguration wifiConfiguration : wifiConfigurations) {
                if (wifiConfiguration.SSID.equals("\"" + ssid + "\"")) {
                    networkId = wifiConfiguration.networkId;
                    Log.i(TAG, "delWifiItem: 找到对应的 ssid,编号为:" + networkId);
                    break;
                }
            }
        }

        if (networkId != -10) {
            Log.i(TAG, "delWifiItem: 执行删除指定网络的过程");
            wifiManager.removeNetwork(networkId);
            result = true;
        }

        wifiConfigurations = wifiManager.getConfiguredNetworks();
        for (WifiConfiguration wifiConfiguration : wifiConfigurations) {
            if (wifiConfiguration.SSID.equals("\"" + ssid + "\"")) {
                Log.i(TAG, "delWifiItem: 又找到对应的 ssid,编号为:" + networkId);
                result = false;
                break;
            }
        }

        return result;
    }

    private boolean connectToSpecSsid(int netId) {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        return wifiManager.enableNetwork(netId,true);
    }

    private boolean disableSpecSsid(int netId) {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        return wifiManager.disableNetwork(netId);
    }

    public static void forgetConfiguration(Context context, WifiConfiguration config) {
        if (config == null) {
            return;
        }

        WifiManager wifiMan = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
        List<WifiConfiguration> configuredNetworks = wifiMan.getConfiguredNetworks();
        if (configuredNetworks == null) {
            Log.e(TAG, "failed to get configured networks");
            return;
        }

        for (WifiConfiguration wc : configuredNetworks) {
            if (wc != null && wc.SSID != null && TextUtils.equals(wc.SSID, config.SSID)) {
                wifiMan.forget(wc.networkId, null);
                Log.d(TAG, "forgot network config: " + wc.toString());
                break;
            }
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.xxxxxx.wifitest7.MainActivity">

    <Button
        android:id="@+id/btnOpenWifi"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginTop="32dp"
        android:text="@string/open_wifi"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        />

    <Button
        android:id="@+id/btnCloseWifi"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="32dp"
        android:layout_marginTop="32dp"
        android:text="@string/close_wifi"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        />

    <TextView
        android:id="@+id/textViewShowResult"
        android:layout_width="321dp"
        android:layout_height="220dp"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginTop="16dp"
        app:layout_constraintLeft_toLeftOf="@+id/btnOpenWifi"
        app:layout_constraintRight_toRightOf="@+id/btnCloseWifi"
        app:layout_constraintTop_toBottomOf="@+id/btnConnect"
        app:layout_constraintHorizontal_bias="0.484"/>

    <Button
        android:id="@+id/btnConnect"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginTop="8dp"
        android:text="@string/connect"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btnAddWifi"/>

    <Button
        android:id="@+id/btnDisConnect"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="32dp"
        android:layout_marginTop="8dp"
        android:text="@string/disconnect"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btnDelWifi"/>

    <Button
        android:id="@+id/btnAddWifi"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="@string/addwifi"
        app:layout_constraintTop_toBottomOf="@+id/btnOpenWifi"
        android:layout_marginStart="32dp"
        app:layout_constraintLeft_toLeftOf="parent"/>

    <Button
        android:id="@+id/btnDelWifi"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="@string/delwifi"
        app:layout_constraintTop_toBottomOf="@+id/btnCloseWifi"
        android:layout_marginEnd="32dp"
        app:layout_constraintRight_toRightOf="parent"/>
</android.support.constraint.ConstraintLayout>