我想做一个片段的功能，当我点击按钮，画廊将打开，然后我选择一个图像，该图像将被放入我的imageview。
这是我写的代码：

class PostFragment : Fragment(R.layout.fragment_post) {

    companion object{
        val IMAGE_REQUEST_CODE = 100
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View{
        val rootView: View = inflater.inflate(R.layout.fragment_post, container, false)

        var ButtonChooseImage: Button = rootView.findViewById(R.id.button_choose_image)
        var postImage: ImageView = rootView.findViewById(R.id.postImage)
        ButtonChooseImage.setOnClickListener{
            openFileChooser()
        }
        return rootView
    }

    private fun openFileChooser() {
        val intent = Intent(Intent.ACTION_PICK)
        intent.type = "image/*"
        startActivityForResult(intent, IMAGE_REQUEST_CODE)
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        val rootView: View = layoutInflater.inflate(R.layout.fragment_post,null)
        var postImage: ImageView = rootView.findViewById(R.id.postImage)

        super.onActivityResult(requestCode, resultCode, data)
        if(requestCode == IMAGE_REQUEST_CODE && resultCode == RESULT_OK){

            postImage.setImageURI(data?.data)
        }
    }
}

一切正常，除了图像没有显示在ImageView中。（在我按下按钮画廊弹出后，我选择了一张图像，但它没有显示在ImageView中。）
我哪里错了？请告诉我。