EasyPermissions 是 Google 官方推荐的权限处理库，但在实际项目中直接使用时，代码仍显冗长。本文介绍一种基于基类封装的方案，将权限申请逻辑收敛到统一入口，降低业务层的接入成本。

依赖配置

// build.gradle.kts
dependencies {
    implementation("pub.devrel:easypermissions:3.0.0")
}

基类封装设计

核心思路是将权限回调、请求码管理、结果分发全部下沉到 BaseActivity，子类只需关注"权限通过后要做什么"。

abstract class BaseActivity : AppCompatActivity(), 
    EasyPermissions.PermissionCallbacks {

    // 权限请求码枚举，避免魔法数字
    protected enum class PermissionRequest(val code: Int) {
        LOCATION(0x01),
        CAMERA(0x02),
        MICROPHONE(0x03),
        BLUETOOTH(0x04)
    }

    // 简化后的回调接口，屏蔽底层细节
    protected interface PermissionResultHandler {
        fun onAcquired(requestCode: Int)
        fun onRejected(requestCode: Int)
    }

    private var resultHandler: PermissionResultHandler? = null

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<String>,
        grantResults: IntArray
    ) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        EasyPermissions.onRequestPermissionsResult(
            requestCode, permissions, grantResults, this
        )
    }

    override fun onPermissionsGranted(requestCode: Int, perms: List<String>) {
        resultHandler?.onAcquired(requestCode)
    }

    override fun onPermissionsDenied(requestCode: Int, perms: List<String>) {
        resultHandler?.onRejected(requestCode)
    }

    // 权限申请入口
    protected fun acquirePermissions(
        rationale: String,
        request: PermissionRequest,
        vararg permissions: String,
        handler: PermissionResultHandler
    ) {
        this.resultHandler = handler
        EasyPermissions.requestPermissions(
            this,
            rationale,
            request.code,
            *permissions
        )
    }

    // 快速检查
    protected fun checkGranted(vararg permissions: String): Boolean {
        return EasyPermissions.hasPermissions(this, *permissions)
    }
}

权限配置集中管理

将不同业务场景的权限清单抽离为独立方法，便于复用和维护。

// BaseActivity 扩展方法
protected fun locationPermissions(): Array<String> = arrayOf(
    Manifest.permission.ACCESS_FINE_LOCATION,
    Manifest.permission.ACCESS_COARSE_LOCATION
)

protected fun bluetoothPermissions(): Array<String> = when {
    Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> arrayOf(
        Manifest.permission.BLUETOOTH_SCAN,
        Manifest.permission.BLUETOOTH_CONNECT,
        Manifest.permission.BLUETOOTH_ADVERTISE,
        Manifest.permission.ACCESS_FINE_LOCATION
    )
    else -> arrayOf(
        Manifest.permission.BLUETOOTH,
        Manifest.permission.BLUETOOTH_ADMIN,
        Manifest.permission.ACCESS_FINE_LOCATION
    )
}

protected fun audioPermissions(): Array<String> = buildList {
    add(Manifest.permission.RECORD_AUDIO)
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
        add(Manifest.permission.FOREGROUND_SERVICE)
    }
}.toTypedArray()

业务层使用示例

以蓝牙场景为例，展示封装后的调用方式。

class DeviceScanActivity : BaseActivity() {

    private fun ensureBluetoothThenScan() {
        if (checkGranted(*bluetoothPermissions())) {
            startBleScan()
            return
        }

        acquirePermissions(
            rationale = "扫描周边设备需要蓝牙和位置权限",
            request = PermissionRequest.BLUETOOTH,
            permissions = *bluetoothPermissions(),
            handler = object : PermissionResultHandler {
                override fun onAcquired(requestCode: Int) {
                    startBleScan()
                }

                override fun onRejected(requestCode: Int) {
                    Toast.makeText(this@DeviceScanActivity, 
                        "权限被拒绝，无法扫描设备", Toast.LENGTH_SHORT).show()
                }
            }
        )
    }

    private fun startBleScan() {
        // 执行实际的蓝牙扫描逻辑
    }
}

进阶：Fragment 场景适配

Fragment 需单独处理，但可复用同一套回调机制。

abstract class BaseFragment : Fragment(), 
    EasyPermissions.PermissionCallbacks {

    protected fun requestFromFragment(
        rationale: String,
        requestCode: Int,
        vararg permissions: String
    ) {
        EasyPermissions.requestPermissions(
            PermissionRequest.Builder(this, requestCode, *permissions)
                .setRationale(rationale)
                .build()
        )
    }

    // 回调实现与 BaseActivity 保持一致...
}

注意事项

• 请求码需在 0-255 范围内，建议使用枚举集中管理
• Android 6.0 以下设备无需动态申请，但库内部已做兼容
• 权限被拒绝且勾选"不再询问"后，需引导用户前往设置页手动开启
• 从 Android 12 开始，蓝牙权限细分为 BLUETOOTH_SCAN、BLUETOOTH_CONNECT 等，需按版本适配