android - requestPermissionLauncher 不显示权限对话框

问题描述

所以我尝试使用新的方式来请求权限（允许系统管理权限请求代码），比如这里写的https://developer.android.com/training/permissions/requesting#allow-system-manage-request-code . 当我点击相机按钮时，我只是得到“权限被拒绝”，但我没有得到一个带有实际权限请求的窗口（我可以允许或拒绝它）。在文档中写道“要在必要时显示系统权限对话框，请在您在上一步中保存的 ActivityResultLauncher 实例上调用 launch() 方法。” 我做错了什么？我想念什么？

在 onViewCreated 我有：

binding.camera.setOnClickListener{
        when {
            ContextCompat.checkSelfPermission(
                    requireContext(),
                    Manifest.permission.CAMERA
            ) == PackageManager.PERMISSION_GRANTED -> {
                // You can use the API that requires the permission.
                //startCamera()
                makeText(activity, "Start camera", LENGTH_SHORT).show()
            }
            shouldShowRequestPermissionRationale(Manifest.permission.CAMERA) -> {
                // In an educational UI, explain to the user why your app requires this
                // permission for a specific feature to behave as expected. In this UI,
                // include a "cancel" or "no thanks" button that allows the user to
                // continue using your app without granting the permission.
                makeText(activity, "Camera is necessary to add content.", LENGTH_SHORT).show()
            }
            else -> {
                    // You can directly ask for the permission.
                    // The registered ActivityResultCallback gets the result of this request.
                    requestPermissionLauncher.launch(
                                    Manifest.permission.CAMERA)
                }
            }
    }

我有这段代码：

// Permission
val requestPermissionLauncher = registerForActivityResult(ActivityResultContracts.RequestPermission()) {
    isGranted: Boolean -> if (isGranted){
        // Permission Accepted
        makeText(activity, "Permission Accepted.", LENGTH_SHORT).show()
    }
    else {
        // Permission Denied
        makeText(activity, "Permission Denied.", LENGTH_SHORT).show()
    }
}

标签： androidkotlin

android - requestPermissionLauncher 不显示权限对话框

问题描述

解决方案

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