Question

我正在制作一个android应用程序，并请求读取存储的权限。

以下是请求权限的代码：

private fun checkPermission():Boolean {
        return checkSelfPermission(this, READ_EXTERNAL_STORAGE) == PERMISSION_GRANTED
}

private fun toast(text: String){
    Toast.makeText(applicationContext, text, Toast.LENGTH_LONG).show()

}
private fun setupPermissions() {
    if (!checkPermission()) {
        var requestCode = 7
        requestPermissions(this, arrayOf(READ_EXTERNAL_STORAGE), requestCode)
        if (!checkPermission()) {
            toast("Permissions not granted")

            val builder = AlertDialog.Builder(this@MainActivity)
            builder.setTitle("Permissions were denied.")
            builder.setMessage("You must allow MyApp access to your files to continue.\n\nNote: If you clicked \"Don't ask again,\" you'll have to enable the permission in settings")
            builder.setPositiveButton("OK") { dialog, which ->
                setupPermissions()
            }
            builder.setNeutralButton("EXIT") { _, _ ->
                Toast.makeText(applicationContext, "You cancelled the dialog.", Toast.LENGTH_SHORT).show()
            }
            val dialog: AlertDialog = builder.create()
            dialog.show()
        }
        else{
            toast("Permissions granted")
        }
    }


}

问题在于它请求了权限，但是即使它尚未被调用，您仍可以在其下看到AlertDialog框：

Screenshot of app when it launches （它说“别再问了”，因为我已经尝试了多次）

它似乎正在运行requestPermissions(this, arrayOf(READ_EXTERNAL_STORAGE), requestCode)，并且没有等待用户选择允许或拒绝，它显示了对话框。

为什么会这样？感谢您的帮助，因为我是Kotlin的新手

Answer 1

Dialog立即出现的原因是，您在请求许可后正在检查是否创建它。

第二个if (!checkPermission())不会有所不同，因为权限更改不会立即发生。您可以尝试执行以下步骤：

删除代码，将Dialog放入setUpPermissions()。

复制并粘贴以下代码：

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (!checkPermission()) {
        toast("Permissions not granted")

        val builder = AlertDialog.Builder(this@MainActivity)
        builder.setTitle("Permissions were denied.")
        builder.setMessage("You must allow MyApp access to your files to continue.\n\nNote: If you clicked \"Don't ask again,\" you'll have to enable the permission in settings")
        builder.setPositiveButton("OK") { dialog, which ->
            setupPermissions()
        }
        builder.setNeutralButton("EXIT") { _, _ ->
            Toast.makeText(applicationContext, "You cancelled the dialog.", Toast.LENGTH_SHORT).show()
        }
        val dialog: AlertDialog = builder.create()
        dialog.show()
    }
    else{
        toast("Permissions granted")
    }
}

这应该是在requestPermission()结果发生之后，它应该检查权限。然后，如果未授予该权限，它将创建Dialog。

让我知道这是否可行，或者由于我自己没有进行测试而遇到任何错误。

即使没有叫过Kotlin android，AlertDialogBox也会显示

1 个答案: