原理

通过向当前Activity添加一个不可见的Fragment，从而实现权限申请流程的封装。

实现

不可见的Fragment

internal class EPermissionFragment : Fragment() {

    private var mCallback: EPermissionCallback? = null


    fun requestPermission(callback: EPermissionCallback, vararg permissions: String) {

        mCallback = callback

        // 申请权限

        requestPermissions(permissions, CODE_REQUEST_PERMISSION)

    }


    override fun onRequestPermissionsResult(

        requestCode: Int,

        permissions: Array<out String>,

        grantResults: IntArray

    ) {

        if (requestCode == CODE_REQUEST_PERMISSION) {

            val deniedList = ArrayList<String>()

            val deniedForeverList = ArrayList<String>()

            grantResults.forEachIndexed { index, result ->

                // 提取权限申请结果

                if (result != PackageManager.PERMISSION_GRANTED) {

                    val permission = permissions[index]

                    deniedList.add(permission)

                    // 是否拒绝且不再显示

                    if (!shouldShowRequestPermissionRationale(permission)) {

                        deniedForeverList.add(permission)

                    }

                }

            }

            if (deniedList.isEmpty()) mCallback?.onAllGranted()

            if (deniedList.isNotEmpty()) mCallback?.onDenied(deniedList)

            if (deniedForeverList.isNotEmpty()) mCallback?.onDeniedForever(deniedForeverList)

        }

    }


    override fun onDestroy() {

        mCallback = null

        super.onDestroy()

    }

}

封装权限申请

// 扩展FragmentActivity

fun FragmentActivity.runWithPermissions(

    vararg permissions: String,

    onDenied: (ArrayList<String>) -> Unit = { _ -> },

    onDeniedForever: (ArrayList<String>) -> Unit = { _ -> },

    onAllGranted: () -> Unit = {}

) {

    if (checkPermissions(*permissions)) {

        onAllGranted()

        return

    }

    // 添加一个不可见的Fragment

    val isFragmentExist = supportFragmentManager.findFragmentByTag(EPermissionFragment.TAG)

    val fragment = if (isFragmentExist != null) {

        isFragmentExist as EPermissionFragment

    } else {

        val invisibleFragment = EPermissionFragment()

        supportFragmentManager.beginTransaction().add(invisibleFragment, EPermissionFragment.TAG).commitNowAllowingStateLoss()

        invisibleFragment

    }

    val callback = object : EPermissionCallback {

        override fun onAllGranted() {

            onAllGranted()

        }


        override fun onDenied(deniedList: ArrayList<String>) {

            onDenied(deniedList)

        }


        override fun onDeniedForever(deniedForeverList: ArrayList<String>) {

            onDeniedForever(deniedForeverList)

        }

    }

    // 申请权限

    fragment.requestPermission(callback, *permissions)

}

使用方法

项目build.gradle添加

allprojects {

    repositories {

        ...

        maven { url 'https://www.jitpack.io' }

        }

}

模块build.gradle添加

dependencies {

    implementation 'com.github.RickyHal:EPermission:$latest_version'

}

在Activity或者Fragment中直接调用

// 申请存储权限

runWithPermissions(

    *EPermissions.STORAGE,

    onDenied = {

        Toast.makeText(this, "STORAGE permission denied", Toast.LENGTH_SHORT).show()

    },

    onDeniedForever = {

        Toast.makeText(this, "STORAGE permission denied forever", Toast.LENGTH_SHORT).show()

    },

    onAllGranted = {

        Toast.makeText(this, "STORAGE permission granted", Toast.LENGTH_SHORT).show()

    }

)

也可以用下面这个简单的方法

runWithStoragePermission(onFailed = {

    Toast.makeText(this, "SMS permission denied", Toast.LENGTH_SHORT).show()

}) {

    Toast.makeText(this, "SMS permission granted", Toast.LENGTH_SHORT).show()

}

一次申请多个权限

runWithPermissions(*EPermissions.CAMERA, *EPermissions.STORAGE,

    onDenied = { deniedList ->

        Toast.makeText(this, "permission denied $deniedList", Toast.LENGTH_SHORT).show()

    },

    onDeniedForever = { deniedForeverList ->

        Toast.makeText(this, "permission denied forever $deniedForeverList", Toast.LENGTH_SHORT).show()

    },

    onAllGranted = {

        Toast.makeText(this, "Permission all granted", Toast.LENGTH_SHORT).show()

    })

如果不需要处理失申请权限败的情况，也可以直接这样写

runWithStoragePermission {

    Toast.makeText(this, "SMS permission granted", Toast.LENGTH_SHORT).show()

}

如果某些操作执行的时候，只能有权限才去执行，则可以使用下面的方法

doWhenPermissionGranted(*EPermissions.CAMERA){

    Toast.makeText(this, "Do this when camera Permission is granted", Toast.LENGTH_SHORT).show()

}

检查权限

if (checkPermissions(*EPermissions.CAMERA)) {

    Toast.makeText(this, "Camera Permission is granted", Toast.LENGTH_SHORT).show()

} else {

    Toast.makeText(this, "Camera Permission is not granted", Toast.LENGTH_SHORT).show()

}

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