Android Wifi开发教程

转载自：https://blog.csdn.net/a1533588867/article/details/52459284

本文主要讲三个方面：

1.wifi热点的创建和关闭

2.wifi的搜索和连接

3.wifi数据传输

一、Wifi热点的创建和关闭

     1.权限申请（如果版本大于6.0，还需要动态申请）

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

     2.动态权限申请

       String[] requestPermission = new String[]{
                Manifest.permission.ACCESS_WIFI_STATE,
                Manifest.permission.ACCESS_WIFI_STATE,
                Manifest.permission.ACCESS_COARSE_LOCATION};
        List<String> needRequest = new ArrayList<>();
        for (int i = 0; i < requestPermission.length; i++) {
            if (ContextCompat.checkSelfPermission(this, requestPermission[i]) == PackageManager.PERMISSION_GRANTED) {
            } else {
                needRequest.add(requestPermission[i]);
            }
        }
        if (needRequest != null && needRequest.size() > 0) {
            ActivityCompat.requestPermissions(this, needRequest.toArray(new String[needRequest.size()]), 0);
        }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        for (int i = 0; i < grantResults.length; i++) {
            if (grantResults[i] != PackageManager.PERMISSION_GRANTED) {
                return;

            }
        }
        Log.d(TAG, "onRequestPermissionsResult: OK");
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }

    ps:但是有些时候我们开发targetSdk写的是22，并没有超过23，但是还是因为没有权限问题而无法使用，这是时候申请权限就不能使用上面这种了，应该是PermissionChecker.checkSelfPermission(this, Manifest.permission.ACCESS_WIFI_STATE
);返回PermissionChecker.PERMISSION_GRANTED权限申请成功

3.wifi热点创建

/**
     * 创建Wifi热点
     */
    private void createWifiHotspot() {
        if (wifiManager.isWifiEnabled()) {
            //如果wifi处于打开状态，则关闭wifi,
            wifiManager.setWifiEnabled(false);
        }
        WifiConfiguration config = new WifiConfiguration();
        config.SSID = WIFI_HOTSPOT_SSID;
        config.preSharedKey = "123456789";
        config.hiddenSSID = true;
        config.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);//开放系统认证
        config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
        config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
        config.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
        config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
        config.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
        config.status = WifiConfiguration.Status.ENABLED;
        //通过反射调用设置热点
        try {
            Method method = wifiManager.getClass().getMethod( "setWifiApEnabled", WifiConfiguration.class, Boolean.TYPE);
            boolean enable = (Boolean) method.invoke(wifiManager, config, true);
            if (enable) {
                textview.setText("热点已开启 SSID:" + WIFI_HOTSPOT_SSID + " password:123456789");
            } else {
                textview.setText("创建热点失败");
            }
        } catch (Exception e) {
            e.printStackTrace();
            textview.setText("创建热点失败");
        }
    }

ps: 在开启热点的时候，我们需要确保WiFi是关闭状态，因为大部分手机都是不支持热点和WiFi是同时开启的。接着就需要创建WifiConfiguration这个类，由于配置我们所要创建的热点的属性。这里我们所需注意的主要是SSID、preSharedKey和KeyMgmt。 分别对应热点的名称、密码和加密方式。

4.wif热点关闭

   /**
     * 关闭WiFi热点
     */
    public void closeWifiHotspot() {
        try {
            Method method = wifiManager.getClass().getMethod("getWifiApConfiguration");
            method.setAccessible(true);
            WifiConfiguration config = (WifiConfiguration) method.invoke(wifiManager);
            Method method2 = wifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
            method2.invoke(wifiManager, config, false);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }