Android 权限申请分享

要求：

1.不用三方框架，减小安装包的大小

2.请求权限的时候，显示请求内容，配合应用市场上架要求

代码实现

调用的代码

//初始化
private val readLauncher = PermissionInfoLauncher(Manifest.permission.READ_CONTACTS) {
    "读取联系人".toast()
}

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    installSplashScreen()
    setContentView(binding.root)

    //注册
    lifecycle.addObserver(readLauncher)
    binding.btnReadContacts.setOnClickListener {
        //具体调用
        readLauncher.request(this)
    }
}

override fun onDestroy() {
    super.onDestroy()
    //解除绑定
    lifecycle.removeObserver(readLauncher)
}

核心实现类，其中 PermissionInfoDialog 、SettingPermissionDialog 是显示信息的弹框，跟设置的弹框，可以根据项目UI要求自行实现

注意Launcher 绑定，不能在OnCreate 中默认调用request，那时候Launcher还未初始化 如果遇到地图定位，在修改权限之后，还要重新自动定位，再加入

setLauncher = owner.registerForActivityResult(ActivityResultContracts.StartActivityForResult())

回调即可

class PermissionInfoObserver(private val permission: String, private val function: () -> Unit) :
    DefaultLifecycleObserver {

    //设计思路，使用lifecycleObserver 实现注册 权限申请 ， 并传入同意之后的方法function，处理不同意的方法
    //除了lifecycleObserver，还可以用Activity ，Fragment的扩展方法实现，效果一致

    private lateinit var permissionLauncher: ActivityResultLauncher<String>

    @StringRes
    var infoRes: Int = R.string.permission_refuse_info_default

    @StringRes
    var setRes: Int = R.string.permission_set_default

    private val infoDialog: PermissionInfoDialog by lazy {
        PermissionInfoDialog.Builder().apply {
            content = CoreUtils.getApp().getString(infoRes)
        }.create()
    }

    override fun onCreate(owner: LifecycleOwner) {
        super.onCreate(owner)
        when (owner) {
            is FragmentActivity -> {
                permissionLauncher = owner.registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted ->
                        infoDialog.dismiss()
                        if (granted) {
                            //处理业务逻辑
                            function()
                        } else {
                            val settingDialog = SettingPermissionDialog.SetBuilder().apply {
                                tvContent = owner.resources.getString(setRes)
                            }.create()
                            settingDialog.show(owner.supportFragmentManager)
                        }
                    }
            }

            else -> {
                throw NullPointerException("${this.javaClass.name}观察的生命周期不是Activity或者Fragment")
            }
        }
    }

    override fun onDestroy(owner: LifecycleOwner) {
        super.onDestroy(owner)
        permissionLauncher.unregister()
        if (infoDialog.isVisible) {
            infoDialog.dismiss()
        }
    }

    fun request(activity: FragmentActivity) {
        infoDialog.show(activity.supportFragmentManager)
        if (::permissionLauncher.isInitialized) {
            permissionLauncher.launch(permission)
        }
    }
}