Java 如何在Android上的MediaStore.Images.Media选定图像后调整图像大小

我目前已成功将移动应用程序中的图像上载到服务器。 我试图找出如何调整图像大小，并可能在发送到服务器之前创建一个缩略图。我在网上找到了很多方法，但都不管用

下面是到目前为止我的代码

            filePath = data.getData();
            try {
                bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
                imageView.setImageBitmap(bitmap);

            } catch (IOException e) {
                e.printStackTrace();
            }
        }


public void uploadMultipart() {

       SessionHandler mySession = new SessionHandler(this);
       User user = mySession.getUserDetails();

       String title = editText.getText().toString().trim();
       String path = getPath(filePath);
       String studentid = user.studentid;
       String email  = user.email;
       String firstname = user.firstname;
       //Toast.makeText(this, firstname, Toast.LENGTH_SHORT).show();

        try {
            String uploadId = UUID.randomUUID().toString();
            uploadReceiver.setDelegate(this);
            uploadReceiver.setUploadID(uploadId);

            new MultipartUploadRequest(this, uploadId, Constants.UPLOAD_URL)
                    .addFileToUpload(path, "image")
                    .addParameter("title", title)
                    .addParameter("studentid", studentid)
                    .addParameter("firstname", firstname)
                    .addParameter("email", email)

                    //.setNotificationConfig(new UploadNotificationConfig())
                    .setMaxRetries(2)
                    .startUpload();
        } catch (Exception exc) {
            Toast.makeText(this, exc.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }

---

要压缩图像，请在活动中写入此方法

public void compressImage(String filePath) {
                try {
                    OutputStream outStream = null;

                   Log.i("filePath",filePath);
                    outStream = new FileOutputStream(filePath);
                    BitmapFactory.Options bmOptions = new BitmapFactory.Options();
                    bmOptions.inSampleSize = 8;
                    bitmap = BitmapFactory.decodeFile(filePath ,bmOptions);

                    bitmap.compress(Bitmap.CompressFormat.JPEG, 50, outStream);


                    outStream.flush();
                    outStream.close();


                    Log.i("file path compress", filePath);

                } catch (Exception e) {

                    Log.i("exception", e.toString());
                }
            }

并在活动结果中调用它

@Override 
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

if(requestCode == TAKE_PHOTO){ //your request code

filePath = data.getData();
        try {

            compressImage(filePath);

            bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
            imageView.setImageBitmap(bitmap);

        } catch (IOException e) {
            e.printStackTrace();
        }
   }
}

您可以使用compressImage方法对图像进行任意压缩

public Bitmap resizeBitmap(Bitmap bitmap, int newWidth, int newHeight) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);

Bitmap resizedBitmap = Bitmap.createBitmap(
    bitmap, 0, 0, width, height, matrix, false);
bitmap.recycle();
return resizedBitmap;

---

}

你说的我都做了，但由于某种原因，没有调整大小。文件已上载，但未进行压缩。