java - 从图库中选择的图像出现 Kotlin 错误

Question

我无法加载所选图像。正在加载默认模板图像。我用帖子中的完整 fragment 代码编辑了它，您能指导我使用哪个参数上传到所选图像吗？

以下更新后的代码可以工作，但只能上传预定义的图像，我无法上传所选图像，我不知道该行上使用哪个参数

if (this.imageUri != imageUri && requestCode == IMAGE_PICK_CODE && resultCode == RESULT_OK) {

class  ReportFragment : Fragment(), OnMapReadyCallback, GoogleMap.OnMapClickListener, GoogleMap.OnCameraIdleListener {
    private var mMapView: MapView? = null
    private var map: GoogleMap? = null
    val CAMERA_PERMISSION_CODE = 0
    val CAMERA_REQUEST_CODE = 10
    lateinit var imageFilePath: String
    private var imgThumb: ImageView? = null
    private var spinner: Spinner? = null
    private var currentLocation: LatLng? = null  // TODO: get current location as static variable
    private var midLatLng: LatLng? = null
    private var lat: Double? = null
    private var lng: Double? = null
    private var objectValues: Array<String>? = null
    private var imageUri: Uri? = null
    private var pictureTaken: Boolean = false
    private var progress: ProgressBar? = null
    val PERMISSION_CODE_READ = 1001
    val PERMISSION_CODE_WRITE = 1002
    val IMAGE_PICK_CODE = 1000
    private val database: FirebaseDatabase? = FirebaseDatabase.getInstance()
    private val markersRef: DatabaseReference? = database!!.getReference("markers")
    private val storage = FirebaseStorage.getInstance()
    private val storageRef: StorageReference = storage.reference
    private var imagesRef: StorageReference? = null
    private val permissoes = arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE)
    inner class GenericFileProvider : FileProvider()


    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        ContextCompat.checkSelfPermission(this.context,
                Manifest.permission.READ_EXTERNAL_STORAGE)
        ContextCompat.checkSelfPermission(this.context,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)
        Permissoes.validarPermissoes(permissoes, this.activity, 1)
        // Inflate the layout for this fragment
        val view = inflater.inflate(R.layout.fragment_report, container, false)

        if (arguments != null && arguments.getDouble("lat") != null) {
            this.lat = arguments.getDouble("lat")
            this.lng = arguments.getDouble("lng")
        }
        this.objectValues = resources.getStringArray(R.array.object_values) // for dropdown

        // TODO       this.currentLocation = Utils.currentLocation
        this.progress = view.findViewById(R.id.progressBar) as ProgressBar

        // Needs to call MapsInitializer before doing any CameraUpdateFactory calls
        try {
            initMap(view, savedInstanceState)
        } catch (e: GooglePlayServicesNotAvailableException) {
            e.printStackTrace()
        }
        this.imgThumb = view.findViewById(R.id.takePictureThumbnail) as ImageButton
        val camBtn = view.findViewById(R.id.takePictureBtn) as ImageButton
        val createBtn = view.findViewById(R.id.createIssueBtn) as Button
        camBtn.setOnClickListener{
            pickImageFromGallery()
        }
        this.imgThumb!!.setOnClickListener{
            takePicture()
        }

        this.spinner = view.findViewById<Spinner>(R.id.object_types_spinner)
        // Create an ArrayAdapter using the string array and a default spinner layout
        val adapter = ArrayAdapter.createFromResource(context, R.array.object_types, android.R.layout.simple_spinner_item)
        // Specify the layout to use when the list of choices appears
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
        this.spinner!!.adapter = adapter

        createBtn.setOnClickListener{
            createIssue(view)
        }

        return view
    }

    fun createIssue(view: View) {
        this.progress!!.visibility = View.VISIBLE
        val layout = view.findViewById<LinearLayout>(R.id.reportLinearLayout)
        layout.alpha = 0.4f

        val random = UUID.randomUUID().toString()
        val imgUrl = "images/issue$random+.jpg"
        val name = view.findViewById<EditText>(R.id.issueNameEditText).text.toString()
        val desc = view.findViewById<EditText>(R.id.issueDescriptionEditText).text.toString()
        val type = this.objectValues!![this.spinner!!.selectedItemPosition]
        var issue = Issue(name, type, this.midLatLng!!.latitude, this.midLatLng!!.longitude, desc, imgUrl, null)

        this.imagesRef = storageRef.child(imgUrl)

        var uploadTask: UploadTask = this.imagesRef!!.putBytes(putImgToBytearray())

        uploadTask.addOnSuccessListener { taskSnapshot ->
            this.progress!!.visibility = View.GONE
            Toast.makeText(context,"upload Done",Toast.LENGTH_LONG).show()
            markersRef!!.child(random).setValue(issue)
            goToDetailsView(issue)
        }.addOnFailureListener {
            this.progress!!.visibility = View.GONE
            Toast.makeText(context,"upload failed",Toast.LENGTH_LONG).show()
        }.addOnProgressListener {
            var prog: Double  = (100.0 * it.bytesTransferred )/ it.totalByteCount
            Log.i("transfer", prog.toString())
            //this.progress!!.setProgress(prog.toInt(), true)
        }
    }

    private fun goToDetailsView(issue: Issue) {
        val args = Bundle()

        val detailsFragment = IssueDetailsFragment()
        args.putDouble("lat", issue.lat)
        args.putDouble("lng", issue.lng)
        args.putString("description", issue.description)
        args.putString("name", issue.name)
        args.putString("type", issue.type)
        args.putString("imgUrl", issue.imgUrl)

        detailsFragment.arguments = args
        val ft = fragmentManager.beginTransaction()
        ft.replace(R.id.main_fragment_content, detailsFragment)
                .setTransition(android.app.FragmentTransaction.TRANSIT_FRAGMENT_FADE)
                .addToBackStack(null).commit()
    }
    private fun putImgToBytearray(): ByteArray {
        val stream = ByteArrayOutputStream()
        val drawable = this.imgThumb!!.drawable as BitmapDrawable
        val bitmap = drawable.bitmap
        bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream)
        return stream.toByteArray()
    }

    private fun initMap(view: View, savedInstanceState: Bundle?) {
        MapsInitializer.initialize(this.activity)
        mMapView = view.findViewById(R.id.mapView)
        mMapView!!.onCreate(savedInstanceState)
        mMapView!!.onResume() //without this, map showed but was empty
        mMapView!!.getMapAsync(this)
    }
    override fun onMapClick(latLan: LatLng) {
        this.map!!.addMarker(MarkerOptions().position(latLan).title("Marker"))
    }

    /**
     * Open a camera activity with the picture returned as a result to onActivityResult
     */
    fun openCamera() {
        try {
            val imageFile = createImageFile()
            val callCameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
            if(callCameraIntent.resolveActivity(activity.packageManager) != null) {
                val authorities = activity.packageName + ".fileprovider"
                this.imageUri = FileProvider.getUriForFile(context, authorities, imageFile)
                callCameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri)
                startActivityForResult(callCameraIntent, IMAGE_PICK_CODE)
            }
        } catch (e: IOException) {
            Toast.makeText(context, "Could not create file!", Toast.LENGTH_SHORT).show()
        }
    }

    /**
     * take a picture but check for camera permissions first
     */
    fun takePicture() {
        val permissionGranted = ActivityCompat.checkSelfPermission(activity, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED
        if  (permissionGranted) {
            openCamera()
        } else {
            ActivityCompat.requestPermissions(activity, arrayOf(Manifest.permission.CAMERA), CAMERA_PERMISSION_CODE)
        }
    }
    private fun checkPermissionForImage() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if ((checkSelfPermission(this.context, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED)
                    && (checkSelfPermission(this.context, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED)
            ) {
                val permission = arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE)
                val permissionCoarse = arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE)

                requestPermissions(permission, PERMISSION_CODE_READ) // GIVE AN INTEGER VALUE FOR PERMISSION_CODE_READ LIKE 1001
                requestPermissions(permissionCoarse, PERMISSION_CODE_WRITE) // GIVE AN INTEGER VALUE FOR PERMISSION_CODE_WRITE LIKE 1002
            } else {
                pickImageFromGallery()
            }
        }
    }
    private fun pickImageFromGallery() {
        val intent = Intent(Intent.ACTION_PICK)
        intent.type = "image/*"
        startActivityForResult(intent, IMAGE_PICK_CODE ) // GIVE AN INTEGER VALUE FOR IMAGE_PICK_CODE LIKE 1000
    }

    /**
     * Open the camera after obtaining the permission
     */
    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
        when (requestCode) {
            CAMERA_PERMISSION_CODE -> {
                if (grantResults.isEmpty() || grantResults[0] != PackageManager.PERMISSION_GRANTED) {
                    Log.i("CAMERA", "Permission has been denied by user")
                } else {
                    openCamera()
                    Log.i("CAMERA", "Permission has been granted by user")
                }
            }
        }
    }

    /**
     * Save the picture to the thumbnail after taking it
     */
    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (this.imageUri != imageUri && requestCode == IMAGE_PICK_CODE && resultCode == RESULT_OK) {


            try {
                pickImageFromGallery()
                //Getting the Bitmap from Gallery
                val bitmap = MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap
                this.imgThumb!!.setImageBitmap(bitmap)
                this.pictureTaken = true
            } catch (e:IOException) {
                e.printStackTrace()
            }
        } else {
            Toast.makeText(context, "Error loading image", Toast.LENGTH_LONG)
        }
    }

    @Throws(IOException::class)
    fun createImageFile(): File {
        val timeStamp: String = SimpleDateFormat("yyyyMMdd_HHmmss").format(Date())
        val imageFileName: String = "JPEG_" + timeStamp + "_"
        val storageDir: File = activity.getExternalFilesDir(Environment.DIRECTORY_PICTURES)
        if(!storageDir.exists()) storageDir.mkdirs()
        val imageFile = File.createTempFile(imageFileName, ".jpg", storageDir)
        imageFilePath = imageFile.absolutePath
        return imageFile
    }

    /**
     * update the the coordinated of the map center when moving the map
     */
    override fun onCameraIdle() {
        this.midLatLng = this.map!!.cameraPosition.target
    }

    override fun onMapReady(googleMap: GoogleMap?) {
        this.map = googleMap
        this.map!!.setOnCameraIdleListener(this)
        this.map!!.setOnMapClickListener(this)
        if (this.lat != null) {
            this.map!!.moveCamera(CameraUpdateFactory.newLatLngZoom(LatLng(this.lat!!, this.lng!!), 8f))
        } else if(this.currentLocation != null) { // TODO
            this.map!!.moveCamera(CameraUpdateFactory.newLatLngZoom(this.currentLocation, 8f))
        } else {
            this.map!!.moveCamera(CameraUpdateFactory.newLatLngZoom(Utils.vienna, 8f)) // Vienna
        }
    }
    override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
    }
    override fun onResume() {
        super.onResume()
        mMapView!!.onResume()
    }

    override fun onStart() {
        super.onStart()
        mMapView!!.onStart()
    }
    override fun onPause() {
        super.onPause()
        mMapView!!.onPause()
    }

    override fun onDestroy() {
        super.onDestroy()
        mMapView!!.onDestroy()
    }

    override fun onLowMemory() {
        super.onLowMemory();
        mMapView!!.onLowMemory();
    }

    override fun onSaveInstanceState(outState: Bundle) {
        super.onSaveInstanceState(outState)
        mMapView!!.onSaveInstanceState(outState)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onDetach() {
        super.onDetach()
    }

}// Required empty public constructor

Answer 1

这是一个空指针异常。 imageUri 为空

MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap

如果你检查 getBitmap() 的实现。

参见

public static final Bitmap getBitmap(ContentResolver cr, Uri url)
                throws FileNotFoundException, IOException {
            InputStream input = cr.openInputStream(url);
            Bitmap bitmap = BitmapFactory.decodeStream(input);
            input.close();
            return bitmap;
        }

你会发现它调用了 openInputStream() ，它需要一个非空的 uri。

public final @Nullable InputStream openInputStream(@NonNull Uri uri)


   override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (this.imageUri != null && requestCode == IMAGE_PICK_CODE && resultCode == RESULT_OK) {

            try {
                //Getting the Bitmap from Gallery
                val bitmap = MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap
                this.imgThumb!!.setImageBitmap(bitmap)
                this.pictureTaken = true
            } catch (e:IOException) {
                e.printStackTrace()
            }
        } else {
            Toast.makeText(context, "Error loading image", Toast.LENGTH_LONG)
        }
    }