说明：

本文主要说明扫码之后自动连接WiFi的一些处理，扫码的流程相对简单，网上教程也比较多，对于目前Android各个版本也没有太多变化。

问题描述：

最近在做项目的时候，发现以前的项目有扫描二维码自动连接WiFi的功能，设备改了生成二维码的方式，然后发现手机无法自动连接WiFi了。

问题原因：

经过代码调试发现：（我都是真机调试）

wifiManager.addNetwork(WifiConfiguration);

在添加WiFi的时候，这行代码始终返回-1，换用同事手机竟然神奇的可以连接，然后一脸蒙蔽，裂开了，不怕有问题，就怕有的有问题，有的没问题。

问题解决：

区别：我测试手机小米10androidQ（andorid 10）的系统，同事手机荣耀androidP的系统，大胆猜测是不是android 10又搞了什么奇怪的东西

根因：皇天不负有心人，上代码：

/**
   * Add a new network description to the set of configured networks.
   * The {@code networkId} field of the supplied configuration object
   * is ignored.
   * The new network will be marked DISABLED by default. To enable it,
   * called {@link #enableNetwork}.
   * @param config the set of variables that describe the configuration,
   *      contained in a {@link WifiConfiguration} object.
   *      If the {@link WifiConfiguration} has an Http Proxy set
   *      the calling app must be System, or be provisioned as the Profile or Device Owner.
   * @return the ID of the newly created network description. This is used in
   *     other operations to specified the network to be acted upon.
   *     Returns {@code -1} on failure.
   * @deprecated
   * a) See {@link WifiNetworkSpecifier.Builder#build()} for new
   * mechanism to trigger connection to a Wi-Fi network.
   * b) See {@link #addNetworkSuggestions(List)},
   * {@link #removeNetworkSuggestions(List)} for new API to add Wi-Fi networks for consideration
   * when auto-connecting to wifi.
   * <b Compatibility Note:</b  For applications targeting
   * {@link android.os.Build.VERSION_CODES#Q} or above, this API will always return {@code -1}.
  @Deprecated
  public int addNetwork(WifiConfiguration config) {
    if (config == null) {
      return -1;
    config.networkId = -1;
    return addOrUpdateNetwork(config);
  }

这是WifiManager.class中addNetwork方法的描述，注意注释中最后一行

{@link android.os.Build.VERSION_CODES#Q} or above, this API will always return {@code -1}.

androidQ或者更高的版本，这个方法始终返回-1，至此问题原因分析完毕，接下来开始解决：官网一顿操作：Android 10的新方案如下连接：https://developer.android.google.cn/guide/topics/connectivity/wifi-bootstrap

代码如下：

public void test()
    if (android.os.Build.VERSION.SDK_INT  = android.os.Build.VERSION_CODES.Q)
      NetworkSpecifier specifier =
          new WifiNetworkSpecifier.Builder()
              .setSsidPattern(new PatternMatcher("此处WiFi名称", PatternMatcher.PATTERN_PREFIX))
              .setWpa2Passphrase("此处WiFi密码")
              .build();
      NetworkRequest request =
          new NetworkRequest.Builder()
              .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
              .removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
              .setNetworkSpecifier(specifier)
              .build();
      ConnectivityManager connectivityManager = (ConnectivityManager)
          context.getSystemService(Context.CONNECTIVITY_SERVICE);
      ConnectivityManager.NetworkCallback networkCallback = new ConnectivityManager.NetworkCallback() {
        @Override
        public void onAvailable(Network network) {
          // do success processing here..
        @Override
        public void onUnavailable() {
          // do failure processing here..