android - 将图像保存到图库中

Question

我有一个带有图片库的应用程序，我希望用户可以将其保存到自己的图库中。 我创建了一个带有单个声音“保存”的选项菜单，但问题是......我怎样才能将图像保存到图库中？

这是我的代码：

@Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle item selection
            switch (item.getItemId()) {
            case R.id.menuFinale:

                imgView.setDrawingCacheEnabled(true);
                Bitmap bitmap = imgView.getDrawingCache();
                File root = Environment.getExternalStorageDirectory();
                File file = new File(root.getAbsolutePath()+"/DCIM/Camera/img.jpg");
                try 
                {
                    file.createNewFile();
                    FileOutputStream ostream = new FileOutputStream(file);
                    bitmap.compress(CompressFormat.JPEG, 100, ostream);
                    ostream.close();
                } 
                catch (Exception e) 
                {
                    e.printStackTrace();
                }



                return true;
            default:
                return super.onOptionsItemSelected(item);
            }
        }

我不确定这部分代码：

File root = Environment.getExternalStorageDirectory();
                File file = new File(root.getAbsolutePath()+"/DCIM/Camera/img.jpg");

保存到图库是否正确？ 不幸的是，代码不起作用：（

Answer 1

MediaStore.Images.Media.insertImage(getContentResolver(), yourBitmap, yourTitle , yourDescription);

以前的代码会在图库的末尾添加图片。如果您想要修改日期以显示在开头或任何其他元数据，请参阅下面的代码（S-K的Cortesy， samkirton ）：

https://gist.github.com/samkirton/0242ba81d7ca00b475b9

/**
 * Android internals have been modified to store images in the media folder with 
 * the correct date meta data
 * @author samuelkirton
 */
public class CapturePhotoUtils {

    /**
     * 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(ContentResolver, Bitmap, String, String)
     */
    public static final String insertImage(ContentResolver cr, 
            Bitmap source, 
            String title, 
            String description) {

        ContentValues values = new ContentValues();
        values.put(Images.Media.TITLE, title);
        values.put(Images.Media.DISPLAY_NAME, title);
        values.put(Images.Media.DESCRIPTION, description);
        values.put(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(Images.Media.DATE_ADDED, System.currentTimeMillis());
        values.put(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 = Images.Thumbnails.getThumbnail(cr, id, Images.Thumbnails.MINI_KIND, null);
                // This is for backward compatibility.
                storeThumbnail(cr, miniThumb, id, 50F, 50F,Images.Thumbnails.MICRO_KIND);
            } else {
                cr.delete(url, null, null);
                url = null;
            }
        } catch (Exception e) {
            if (url != null) {
                cr.delete(url, null, null);
                url = null;
            }
        }

        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 static final 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(Images.Thumbnails.KIND,kind);
        values.put(Images.Thumbnails.IMAGE_ID,(int)id);
        values.put(Images.Thumbnails.HEIGHT,thumb.getHeight());
        values.put(Images.Thumbnails.WIDTH,thumb.getWidth());

        Uri url = cr.insert(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) {
            return null;
        } catch (IOException ex) {
            return null;
        }
    }
}

Answer 2

实际上，您可以在任何地方保存图片。如果要保存在公共空间中，任何其他应用程序都可以访问，请使用以下代码：

storageDir = new File(
    Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES
    ), 
    getAlbumName()
);

图片没有进入相册。为此，您需要调用扫描：

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}

您可以在https://developer.android.com/training/camera/photobasics.html#TaskGallery

找到更多信息

Answer 3

我已经尝试过很多东西让它在Marshmallow和Lollipop上运作。 最后，我最终将保存的图片移动到DCIM文件夹（新的Google Photo应用程序扫描图像只有当它们显然位于此文件夹内时）

public static File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
         .format(System.currentTimeInMillis());
    File storageDir = new File(Environment
         .getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM) + "/Camera/");
    if (!storageDir.exists())
        storageDir.mkdirs();
    File image = File.createTempFile(
            timeStamp,                   /* prefix */
            ".jpeg",                     /* suffix */
            storageDir                   /* directory */
    );
    return image;
}

然后是扫描文件的标准代码，您可以在Google Developers site too中找到。

public static void addPicToGallery(Context context, String photoPath) {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(photoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    context.sendBroadcast(mediaScanIntent);
}

请记住，此文件夹无法存在于世界上的每个设备中，并且从Marshmallow（API 23）开始，您需要向用户请求WRITE_EXTERNAL_STORAGE的权限。

Answer 4

根据this course，正确的方法是：

Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES
    )

这将为您提供图库目录的根路径。

Answer 5

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}

Answer 6

您可以在相机文件夹中创建目录并保存。完成后扫描一下。它会立即在图库中显示您的图像。干杯!!

            String root = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).toString()+ "/Camera/Your_Directory_Name";
            File myDir = new File(root);
            myDir.mkdirs();
            String fname = "Image-" + image_name + ".png";
            File file = new File(myDir, fname);
            System.out.println(file.getAbsolutePath());
            if (file.exists()) file.delete();
            Log.i("LOAD", root + fname);
            try {
                FileOutputStream out = new FileOutputStream(file);
                finalBitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
                out.flush();
                out.close();
            } catch (Exception e) {
                e.printStackTrace();
            }

            MediaScannerConnection.scanFile(context, new String[]{file.getPath()}, new String[]{"image/jpeg"}, null);

Answer 7

我带着同样的疑问来到这里但是对于Android的Xamarin，我在保存文件后使用了Sigrist答案来执行此方法：

private void UpdateGallery()
{
    Intent mediaScanIntent = new Intent(Intent.ActionMediaScannerScanFile);
    Java.IO.File file = new Java.IO.File(_path);
    Android.Net.Uri contentUri = Android.Net.Uri.FromFile(file);
    mediaScanIntent.SetData(contentUri);
    Application.Context.SendBroadcast(mediaScanIntent);
} 

它解决了我的问题，Thx Sigrist。我把它放在这里因为我没有找到关于Xamarin的这个问题，我希望它可以帮助其他人。

Answer 8

在我的情况下，上述解决方案不起作用我必须执行以下操作：

sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(f)));

Answer 9

这对我有用：

 private fun saveBitmapAsImageToDevice(bitmap: Bitmap?) {
    // Add a specific media item.
    val resolver = this.contentResolver

    val imageStorageAddress = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
        MediaStore.Images.Media.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
    } else {
        MediaStore.Images.Media.EXTERNAL_CONTENT_URI
    }

    val imageDetails = ContentValues().apply {
        put(MediaStore.Images.Media.DISPLAY_NAME, "my_app_${System.currentTimeMillis()}.jpg")
        put(MediaStore.MediaColumns.MIME_TYPE, "image/jpeg")
        put(MediaStore.MediaColumns.DATE_ADDED, System.currentTimeMillis())
    }

    try {
        // Save the image.
        val contentUri: Uri? = resolver.insert(imageStorageAddress, imageDetails)
        contentUri?.let { uri ->
            // Don't leave an orphan entry in the MediaStore
            if (bitmap == null) resolver.delete(contentUri, null, null)
            val outputStream: OutputStream? = resolver.openOutputStream(uri)
            outputStream?.let { outStream ->
                val isBitmapCompressed =
                    bitmap?.compress(Bitmap.CompressFormat.JPEG, 95, outStream)
                if (isBitmapCompressed == true) {
                    outStream.flush()
                    outStream.close()
                }
            } ?: throw IOException("Failed to get output stream.")
        } ?: throw IOException("Failed to create new MediaStore record.")
    } catch (e: IOException) {
        throw e
    }
}

Answer 10

 String filePath="/storage/emulated/0/DCIM"+app_name;
    File dir=new File(filePath);
    if(!dir.exists()){
        dir.mkdir();
    }

此代码位于onCreate方法中。此代码用于创建app_name目录。 现在，可以使用android中的默认文件管理器应用程序访问此目录。 在需要的地方使用此字符串filePath来设置目标文件夹。 我确信这个方法也可以在Android 7上运行，因为我测试了它。因此，它也适用于其他版本的android。

Answer 11

只需在保存完成后扫描您的媒体即可。

 BitmapDrawable drawable = (BitmapDrawable) imageView.getDrawable();
            Bitmap bitmap = drawable.getBitmap();

            File filepath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
            File dir = new File(filepath.getAbsolutePath()+"/Pro Scanner/");
            if(!dir.exists()){
                dir.mkdir();
            }
            File file = new File(dir,System.currentTimeMillis()+"_Pro_Scanner.png");
            try {
                outputStream = new FileOutputStream(file);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
                downloadQRCode.setVisibility(View.VISIBLE);
                loadingBar.setVisibility(View.INVISIBLE);
            }
            bitmap.compress(Bitmap.CompressFormat.PNG,100,outputStream);
            Toast.makeText(GenerateQRCodeActivity.this, "QR image saved successfully", Toast.LENGTH_SHORT).show();
            try {
                outputStream.flush();
                outputStream.close();
                loadingBar.setVisibility(View.INVISIBLE);
                downloadDone.setVisibility(View.VISIBLE);
                downloadDone.setAnimation(bottomAnimation);
            } catch (IOException e) {
                downloadQRCode.setVisibility(View.VISIBLE);
                loadingBar.setVisibility(View.INVISIBLE);
                e.printStackTrace();
            }

            MediaScannerConnection.scanFile(GenerateQRCodeActivity.this,new String[]{file.getPath()},new String[] {"image/jpeg"},null);

这些代码和大家一样。如果你在这之后尝试下面的代码，它会起作用。你只需要这一行代码：

MediaScannerConnection.scanFile(GenerateQRCodeActivity.this,new String[]{file.getPath()},new String[] {"image/jpeg"},null);

轰隆隆！！！您现在可以在图库中获取您保存的图片。