問題描述
Android轉換為位圖崩潰 (Android Converting to bitmap crash)
Ok so I am supposed to make an android application but for some reason, I cannot convert my picture to a bitmap image. It's a .png image and when I try to convert it in my code, my application just crashes, no errorcode or nothing. Ive tried fixing it a ton of times, but I'm just not that good in programming and I need help, it just won't work.
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == FOTO_NEMEN && resultCode == RESULT_OK)
{
final File file = temp;
try {
String urienzo = "file:///sdcard/DCIM/2013‑01‑30_13‑27‑28.png";
Uri uri = Uri.parse(urienzo);
Bitmap foto = MediaStore.Images.Media.getBitmap(this.getContentResolver(), uri);
if (foto == null) {
Toast.makeText(this, Uri.fromFile(file).toString(), Toast.LENGTH_SHORT).show();
return;
}
ByteArrayOutputStream bos = new ByteArrayOutputStream();
foto.compress(Bitmap.CompressFormat.PNG, 0 , bos);
final byte[] bytes = bos.toByteArray();
bos.close();
AsyncTask<Void,Void,Void> taak = new AsyncTask<Void,Void,Void>() {
@Override
protected Void doInBackground(Void... params) {
stuurAfbeelding(bytes);
return null;
}
};
taak.execute(null,null);
} catch (IOException e) {
Log.e("Snapper","Fout bij foto nemen: " + e);
}
}
}
Whenever I get to the bitmap foto part, it crashes my application without any error message. The reason my URI is hardcoded is because I think the URI.fromfile was giving me the wrong URI, so I wanted to be sure. Now it just crashes and I have no idea what is wrong with my code. Could someone aid me?
‑‑‑‑‑
參考解法
方法 1:
In my opinion you get an outOfMemmoryError.
for getting bitmap from uri you should use something like this:
public static Bitmap getThumbnail(Uri uri) throws FileNotFoundException, IOException{
InputStream input = this.getContentResolver().openInputStream(uri);
BitmapFactory.Options onlyBoundsOptions = new BitmapFactory.Options();
onlyBoundsOptions.inJustDecodeBounds = true;
onlyBoundsOptions.inDither=true;//optional
onlyBoundsOptions.inPreferredConfig=Bitmap.Config.ARGB_8888;//optional
BitmapFactory.decodeStream(input, null, onlyBoundsOptions);
input.close();
if ((onlyBoundsOptions.outWidth == ‑1) || (onlyBoundsOptions.outHeight == ‑1))
return null;
int originalSize = (onlyBoundsOptions.outHeight > onlyBoundsOptions.outWidth) ? onlyBoundsOptions.outHeight : onlyBoundsOptions.outWidth;
double ratio = (originalSize > THUMBNAIL_SIZE) ? (originalSize / THUMBNAIL_SIZE) : 1.0;
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inSampleSize = getPowerOfTwoForSampleRatio(ratio);
bitmapOptions.inDither=true;//optional
bitmapOptions.inPreferredConfig=Bitmap.Config.ARGB_8888;//optional
input = this.getContentResolver().openInputStream(uri);
Bitmap bitmap = BitmapFactory.decodeStream(input, null, bitmapOptions);
input.close();
return bitmap;
}
private static int getPowerOfTwoForSampleRatio(double ratio){
int k = Integer.highestOneBit((int)Math.floor(ratio));
if(k==0) return 1;
else return k;
}
where THUMBNAIL_SIZE is size of yout thumbnail you want to get. So, it works fine andI use this code in my applications0
link How to get Bitmap from an Uri?
方法 2:
You could something like this :
Bitmap image;
ByteArrayOutputStream stream = new ByteArrayOutputStream();
image.compress(Bitmap.CompressFormat.PNG, 100, stream);
and for getting it from the intent you could try something like this :
bitmap = android.provider.MediaStore.Images.Media.getBitmap(getContentResolver(), intent.getData());
String path = getRealPathFromURI(context, intent.getData());
bitmap = scaleImage(imageView, path);
where
private String getRealPathFromURI(Context context, Uri contentUri) {
String[] proj = { MediaStore.Images.Media.DATA };
CursorLoader loader = new CursorLoader(context, contentUri, proj, null, null, null);
Cursor cursor = loader.loadInBackground();
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
方法 3:
I imagine it's crashing because that's not how you load a image from a file.
the code is MUCH simpler than what you're trying:
Bitmap bmp = BitmapFactory.decodeFile(urienzo);
and that's all! Just be sure that this path is correct, because it doesn't look correct to me.
also, if you're loading a big image (e.g. 4MP)it will crash with out of memory, because the idea of Bitmaps is to use to put stuff on the screen which currently is around HD to FullHD resolutions.
(by Eneko Lismont、pavko_a、lokoko、Budius)