我使用kotlin编写了将图像上传到服务器的代码，即用户通过相机拍照，然后当用户单击发送按钮时将图像显示在imageView中，我希望将ImageView中的图像发送到服务器，但我不知道如何将 ImageView 中的图像更改为可以发送到服务器的文件。
我设计了代码来捕获图像并在图像视图中设置图像以预览它，但不知道如何使用http请求将其上传到服务器。
用于打开相机并将图像设置到图像视图中：
private fun openCamera(){
val values = ContentValues()
values.put(MediaStore.Images.Media.TITLE, "New Picture")
values.put(MediaStore.Images.Media.DESCRIPTION, "From Camera")
private fun openCamera() {
val values = ContentValues()
values.put(MediaStore.Images.Media.TITLE, "New Picture")
values.put(MediaStore.Images.Media.DESCRIPTION, "From Camera")
image_uri = contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
val cameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, image_uri)
startActivityForResult(cameraIntent, IMAGE_CAPTURE_CODE)
}
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
when (requestCode) {
PERMISSION_CODE_CAM -> {
if (grantResults.size!! > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
openCamera()
} else {
Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show()
}
}
}
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
super.onActivityResult(requestCode, resultCode, data)
if (resultCode == Activity.RESULT_OK && resultCode == IMAGE_CAPTURE_CODE) {
imageView.setImageURI(image_uri)
}
}
我想使用http请求将图像上传到服务器，我在java中得到了很多代码，但在kotlin中却没有。我不知道如何在 kotlin 中上传。
因为这个问题仍然悬而未决。我们可以使用 OKHTTP 库，它非常易于使用，并且我们只需编写很少的代码。我在这里写了一篇关于该主题的详细文章
在 Android Kotlin 中将图像或文件上传到服务器
我不会再次复制相同的代码，我已经编写了一个UploadUtility 类。只需从上面的链接将其复制到您的项目中，它就会完成剩下的工作。
API接口
@Multipart
@POST("your_url")
suspend fun uploadImage(
@Part file:MultipartBody.Part
): Response<String>
Kotlin 代码
val file: File = ImagePicker.getFile(data)!!
val requestFile =RequestBody.create("multipart/form-data".toMediaTypeOrNull(),file)
val requestFile=RequestBody.create(MediaType.parse("image/*"),file)
val body = MultipartBody.Part.createFormData("profile_picture", file.name, requestFile)
uploadImage(body)
这是使用 kotlin Retrofit 代码上传图像 100% 工作
private fun UploedImage(User_id:String , newfile: File) {
Commons.showProgressDialog(this@StoreDetailActivity)
//creating a file
var requestFile: RequestBody? = null
var document: MultipartBody.Part
var ImageUloloadgetCall: Call<ImageUloloadgetUrlModel?>? = null
if (newfile != null) {
val MEDIA_TYPE_IMAGE = "image/*".toMediaTypeOrNull()
requestFile = create(MEDIA_TYPE_IMAGE, newfile)
document = createFormData(
"image",
newfile.getName(),
requestFile
)
val userId= create("text/plain".toMediaTypeOrNull(), User_id)
ImageUloloadgetCall = getApiInstance().ImageUpload(
alldata,
document
)
}
ImageUloloadgetCall!!.enqueue(object : Callback<ImageUloloadgetUrlModel?> {
override fun onResponse(
call: Call<ImageUloloadgetUrlModel?>,
response: Response<ImageUloloadgetUrlModel?>
) {
dismissProgressDialog()
if (!response.isSuccessful()) {
Log.d(
TAG,
"onResponse: fail " + response.code()
)
Toast.makeText(
this@StoreDetailActivity,
"" + response.message(),
Toast.LENGTH_SHORT
).show()
return
}
Log.d(
TAG,
"onResponse: success" + response.code() + response.body()
)
if (response.body() != null) {
var imageUloloadgetUrlModel: ImageUloloadgetUrlModel? = null
try {
imageUloloadgetUrlModel = response.body()
} catch (e: Exception) {
Toast.makeText(
this@StoreDetailActivity,
"Error in response",
Toast.LENGTH_SHORT
).show()
return
}
} else {
Toast.makeText(
this@StoreDetailActivity,
"Invalid response from server",
Toast.LENGTH_SHORT
).show()
}
}
override fun onFailure(call: Call<ImageUloloadgetUrlModel?>, t: Throwable) {
dismissProgressDialog()
}
})
}
您可以使用这些功能通过相机捕获图像：
public static Uri getTakenPictureUri(Context mContext, Intent data) {
Uri selectedImage = data.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = mContext.getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
cursor.close();
picturePath = "file://" + picturePath;
LogHelper.trace("Selected file uri:" + picturePath);
return Uri.parse(picturePath);
}
public static File createImageFile() throws IOException {
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = MyPharmacy.getmInstance().getExternalCacheDir();
LogHelper.trace("createImageFile:" + storageDir.getAbsolutePath());
File image = File.createTempFile(
imageFileName,
".jpg",
storageDir
);
return image;
}
public static File openCamera(Activity mActivity, int requestCode) {
Intent camera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
try {
File photoFile = createImageFile();
if (photoFile != null) {
Uri photoURI = FileProvider.getUriForFile(MyPharmacy.getmInstance(), BuildConfig.APPLICATION_ID + ".provider", photoFile);
camera.putExtra(MediaStore.EXTRA_OUTPUT,
photoURI);
if (camera.resolveActivity(mActivity.getPackageManager()) != null) {
mActivity.startActivityForResult(camera, requestCode);
return photoFile;
}
}
} catch (IOException ex) {
}
return null;
}
public static File openCamera(Fragment fragment, int requestCode) {
Intent camera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
try {
File photoFile = createImageFile();
if (photoFile != null) {
Uri photoURI = FileProvider.getUriForFile(MyPharmacy.getmInstance(), BuildConfig.APPLICATION_ID + ".provider", photoFile);
camera.putExtra(MediaStore.EXTRA_OUTPUT,
photoURI);
if (camera.resolveActivity(fragment.getActivity().getPackageManager()) != null) {
fragment.startActivityForResult(camera, requestCode);
return photoFile;
}
}
} catch (IOException ex) {
}
return null;
}
然后使用以下代码通过改造上传
public static void uploadImage(final String filePath,
final String token,
final APIResponseCallback<UploadResponse> cb) {
if (filePath != null && !filePath.isEmpty()) {
final File file = new File(filePath);
if (file.exists()) {
Glide.with(App.getmInstance().getContext()).load(file).asBitmap().override(700, 700).into(new SimpleTarget<Bitmap>() {
@Override
public void onResourceReady(Bitmap bitmap, GlideAnimation<? super Bitmap> glideAnimation) {
OutputStream os = null;
try {
String realPath = StorageHelper.getRealPathFromUri(App.getmInstance().getContext(), Uri.fromFile(file));
os = new BufferedOutputStream(new FileOutputStream(file));
bitmap.compress(Bitmap.CompressFormat.JPEG, 80, os);
os.flush();
os.close();
} catch (java.io.IOException e) {
e.printStackTrace();
}
if (file != null) {
// creates RequestBody instance from file
RequestBody requestFile = RequestBody.create(MediaType.parse("image/*"), file);
// MultipartBody.Part is used to send also the actual filename
MultipartBody.Part body = MultipartBody.Part.createFormData("file", file.getName(), requestFile);
// adds another part within the multipart request
String descriptionString = "Image";
RequestBody description = RequestBody.create(okhttp3.MultipartBody.FORM, descriptionString);
// executes the request
ServiceGenerator.getAPIServices().uploadImage(body, description, token).enqueue(new Callback<UploadResponse>() {
@Override
public void onResponse(Call<UploadResponse> call, Response<UploadResponse> response) {
if (response.isSuccessful()) {
cb.onSuccess(response.body());
} else {
checkError(response, token);
}
}
@Override
public void onFailure(Call<UploadResponse> call, Throwable t) {
cb.onError(t);
}
});
}
}
});
}
}
}
API接口为：
@Multipart
@POST("Uploads/image/upload")
Call<UploadResponse> uploadImage(@Part MultipartBody.Part file,
@Part("description") RequestBody description,
@Query("access_token") String token);
此外，您还可以将这些代码转换为 kotlin 等效代码。