问题描述
我正在尝试向图库添加新图像.我通过意图选择了一个已经存在的图像,然后调整大小并压缩它.
I am trying to add a new image to the gallery. I pick an already existing image though an intent and then resize and compress it.
然后我存储生成的位图:
Then I store the resulting bitmap:
public static File compressAndSaveImage(Context ctx, Uri imageUri) throws FileNotFoundException {
File file = null;
if (imageUri != null) {
ContextWrapper cw = new ContextWrapper(ctx);
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
file = new File(directory, imageUri.getLastPathSegment());
System.out.println("storing to " + file);
InputStream input = ctx.getContentResolver().openInputStream(imageUri);
Bitmap b = ImageManager.resize(BitmapFactory.decodeStream(input),
ctx.getResources().getDimension(R.dimen.player_thumb_w),
ctx.getResources().getDimension(R.dimen.player_thumb_h));
FileOutputStream fos = new FileOutputStream(file);
if (b.compress(Bitmap.CompressFormat.PNG, 100, fos)) {
System.out.println("Compression success");// bmp is your Bitmap instance
}
addPictureToGallery(ctx, file);
}
return file;
}
但是当我尝试将图像添加到图库时,没有任何错误,并且未添加图像.我已经尝试了以下两种方法:
But when I try to add the image to the gallery, I get no errors and the image is not added. I have tried both the methods below:
private static void addPictureToGallery(Context ctx, File filepath) {
// Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
// System.out.println("Publish: " + filepath.exists());
// System.out.println("Publish: " + filepath.getAbsolutePath());
// Uri contentUri = Uri.fromFile(filepath);
// mediaScanIntent.setData(contentUri);
// ctx.sendBroadcast(mediaScanIntent);
MediaScannerConnection.scanFile(
ctx,
new String[]{filepath.getAbsolutePath()},
null,
new MediaScannerConnection.OnScanCompletedListener() {
@Override
public void onScanCompleted(String path, Uri uri) {
Log.w("mydebug", "file " + path + " was scanned successfully: " + uri);
}
});
}
}
回调将打印以下行:
file /data/data/test.myapps.appname/app_imageDir/6045564126748266738 was scanned successfully: content://media/external/file/7838
我想念什么?
推荐答案
由于没有时间去详细介绍事物,我将其作为注释,但是显然太长了.尝试这样的事情(我将其用于将位图存储到图库中).需要注意的是,除了扫描图像外,您似乎没有做任何其他事情.现在看来,您正在将文件存储到内部存储中,而不是手机内容(图库)中.
I would put this as a comment as I don't have time to really go into detail about things, but it's obviously too long. Try something like this (I use this for storing bitmaps to the gallery). As a note, it doesn't seem you are doing anything but scanning an image. Right now it seems you are storing the file to your internal storage, not your phones content (gallery).
假设我们正在从ActivityA.class扩展了Activity
/**
* Will save our card (currently set as a bitmap) as a jpeg and save it into our devices
* native photo gallery. Unfortunately, the default method for this will add the image to the bottom
* of the gallery by default, that is no good. This more complex method that utilizes Android's
* native methods will allow us to store the bitmap at the top of the gallery by setting it's
* meta data to today's date.
*/
public class SaveBitmapToDevice extends AsyncTask<Bitmap, Void, String>{
private final ShareType type;
public SaveBitmapToDevice(ShareType type){
this.type = type;
}
@Override
protected String doInBackground(Bitmap... cards) {
return insertImageIntoGallery(getContentResolver(), cards[0], getString(R.string.card_gallery_title),
getString(R.string.card_gallery_label));
}
/**
* A copy of the Android internals insertImage method, this method populates the
* meta data with DATE_ADDED and DATE_TAKEN. This fixes a common problem where media
* that is inserted manually gets saved at the end of the gallery (because date is not populated).
* @see android.provider.MediaStore.Images.Media#insertImage(android.content.ContentResolver, Bitmap, String, String).
* If the MediaStore not available, we will redirect the file to our alternative source, the SD card.
*/
public String insertImageIntoGallery(ContentResolver cr, Bitmap source, String title, String description) {
ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.TITLE, title);
values.put(MediaStore.Images.Media.DISPLAY_NAME, title);
values.put(MediaStore.Images.Media.DESCRIPTION, description);
values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
// Add the date meta data to ensure the image is added at the front of the gallery
values.put(MediaStore.Images.Media.DATE_ADDED, System.currentTimeMillis());
values.put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis());
Uri url = null;
String stringUrl = null; /* value to be returned */
try {
url = cr.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
if (source != null) {
OutputStream imageOut = cr.openOutputStream(url);
try {
source.compress(Bitmap.CompressFormat.JPEG, 50, imageOut);
} finally {
imageOut.close();
}
long id = ContentUris.parseId(url);
// Wait until MINI_KIND thumbnail is generated.
Bitmap miniThumb = MediaStore.Images.Thumbnails.getThumbnail(cr, id, MediaStore.Images.Thumbnails.MINI_KIND, null);
// This is for backward compatibility.
storeThumbnail(cr, miniThumb, id, 50F, 50F, MediaStore.Images.Thumbnails.MICRO_KIND);
} else {
cr.delete(url, null, null);
return storeToAlternateSd(source, title);
// url = null;
}
} catch (Exception e) {
if (url != null) {
cr.delete(url, null, null);
return storeToAlternateSd(source, title);
// url = null;
}
}
savedOnSD = false;
if (url != null) {
stringUrl = url.toString();
}
return stringUrl;
}
/**
* A copy of the Android internals StoreThumbnail method, it used with the insertImage to
* populate the android.provider.MediaStore.Images.Media#insertImage with all the correct
* meta data. The StoreThumbnail method is private so it must be duplicated here.
* @see android.provider.MediaStore.Images.Media (StoreThumbnail private method).
*/
private Bitmap storeThumbnail(
ContentResolver cr,
Bitmap source,
long id,
float width,
float height,
int kind) {
// create the matrix to scale it
Matrix matrix = new Matrix();
float scaleX = width / source.getWidth();
float scaleY = height / source.getHeight();
matrix.setScale(scaleX, scaleY);
Bitmap thumb = Bitmap.createBitmap(source, 0, 0,
source.getWidth(),
source.getHeight(), matrix,
true
);
ContentValues values = new ContentValues(4);
values.put(MediaStore.Images.Thumbnails.KIND,kind);
values.put(MediaStore.Images.Thumbnails.IMAGE_ID,(int)id);
values.put(MediaStore.Images.Thumbnails.HEIGHT,thumb.getHeight());
values.put(MediaStore.Images.Thumbnails.WIDTH,thumb.getWidth());
Uri url = cr.insert(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, values);
try {
OutputStream thumbOut = cr.openOutputStream(url);
thumb.compress(Bitmap.CompressFormat.JPEG, 100, thumbOut);
thumbOut.close();
return thumb;
} catch (FileNotFoundException ex) {
Log.e("IMAGE_COMPRESSION_ERROR", "File not found");
ex.printStackTrace();
return null;
} catch (IOException ex) {
Log.e("IMAGE_COMPRESSION_ERROR", "IO Exception");
ex.printStackTrace();
return null;
}
}
/**
* If we have issues saving into our MediaStore, save it directly to our SD card. We can then interact with this file
* directly, opposed to pulling from the MediaStore. Again, this is a backup method if things don't work out as we
* would expect (seeing as most devices will have a MediaStore).
*
* @param src
* @param title
* @return - the file's path
*/
private String storeToAlternateSd(Bitmap src, String title){
if(src == null)
return null;
File sdCardDirectory = new File(Environment.getExternalStorageDirectory() + File.separator + "My Cards");
if(!sdCardDirectory.exists())
sdCardDirectory.mkdir();
SimpleDateFormat sdf = new SimpleDateFormat("MM-dd-yyyy - (hh.mm.a)", Locale.US);
File image = new File(sdCardDirectory, title + " -- [" + sdf.format(new Date()) + "].jpg");
try {
FileOutputStream imageOut = new FileOutputStream(image);
src.compress(Bitmap.CompressFormat.JPEG, 100, imageOut);
imageOut.close();
savedOnSD = true;
return image.getAbsolutePath();
} catch (FileNotFoundException ex) {
ex.printStackTrace();
return null;
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
}
@Override
public void onPostExecute(String url){
if(url != null){
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
if(savedOnSD){
File file = new File(url);
if(file.exists())
intent.setDataAndType(Uri.fromFile(file), "image/jpeg");
else
return;
}
else
intent.setDataAndType(Uri.parse(url), "image/jpeg");
ActivityA.this.startActivity(intent);
}
else
Toast.makeText(ActivityA.this, getString(R.string.error_compressing), Toast.LENGTH_SHORT).show();
}
}
这篇关于将图像添加到Media Gallery-Android的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!