android判断是否打开WIFI，进入WIFI设置页面

 if (isWifiOpened() == true) {
                        enterActivity(MainActivity.class);//如果已经连接，页面跳转
                        finish();
                    } else {
                        startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS)); //直接进入手机中的wifi网络设置界面
                        if (isWifiOpened() == true) {
                          //如果已经连接，页面跳转
                            enterActivity(MainActivity.class);
                            finish();
                        }
                    }


    private boolean isWifiOpened() {
        WifiManager wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        return wifiManager.isWifiEnabled();
    }