Android - 压缩位图，然后将其保存到SDCARD的活动结果中 _Android

学向勤中得，萤窗万卷书。这篇文章主要讲述Android - 压缩位图，然后将其保存到SDCARD的活动结果中相关的知识，希望能为你提供帮助。
我一直在讨论这个问题，并不确定该怎么做。我要做的是：拍照，压缩到png（保持原始尺寸），然后将其保存到sdCard。我需要这样做的原因是因为我必须再次重新压缩它，然后Base64编码它，以便我可以将它发送到服务器。问题是1.文件太大2.我的内存不足3.不确定我是否正确执行此操作。
谢谢你的帮助
这是我的代码：

@Override public void onClick(View button) { switch (button.getId()) { case R.id.cameraButton: Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); cameraIntent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File("/sdcard/test.png"))); startActivityForResult(cameraIntent, CAMERA_PIC_REQUEST); break; case R.id.galleryButton: sendToDatabase(); break; } }// Camera on activity for result - save it as a bmp and place in imageview protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == CAMERA_PIC_REQUEST) { // do something }if (resultCode == Activity.RESULT_OK) { Log.d(TAG, "result ok"); picture = BitmapFactory.decodeFile("/sdcard/test.png"); // Create string to place it in sd card String extStorageDirectory = Environment .getExternalStorageDirectory().toString(); //create output stream OutputStream outputStream = null; //create file File file = new File(extStorageDirectory, "test.png"); try { outputStream = new FileOutputStream(file); picture.compress(Bitmap.CompressFormat.PNG, 80, outputStream); //picture.recycle(); outputStream.flush(); outputStream.close(); } catch (IOException e){ Log.d(TAG, "ERROR"); } imageView.setImageBitmap(picture); } }public void sendToDatabase() { InputStream inputStream = null; //get the picture from location picture = BitmapFactory.decodeFile("/sdcard/test.png"); // CONVERT: ByteArrayOutputStream outStream = new ByteArrayOutputStream(); Boolean didItWork = picture.compress(Bitmap.CompressFormat.PNG, 50, outStream); picture.recycle(); if (didItWork = true) { Log.d(TAG, "compression worked"); } Log.d(TAG, "AFTER. Height: " + picture.getHeight() + " Width: " + picture.getWidth()); final byte[] ba = outStream.toByteArray(); try { outStream.close(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } }

答案【Android - 压缩位图，然后将其保存到SDCARD的活动结果中】当你做picture.compress（Bitmap.CompressFormat.PNG，50，outStream）; 压缩不能作为无损的PNG工作，将忽略质量设置。因此参数50在这种情况下不起作用。所以我建议你将CompressFormat.PNG改为CompressFormat.JPEG。