Question

我正在尝试构建像Android原生图片库这样的图片库。我正在使用CursorAdapter，带有磁盘缓存和Mem缓存，我将所有图像调整到最小尺寸，还尝试了BitmapFactory的inBitamp选项，似乎没有什么能像普通图库一样快速和平滑地加载

这是Runnable，它主要完成所有加载。

    /**
 * Class to asynchronously perform the loading of the bitmap
 */
public class ImageCalcInSampleRunnable implements Runnable {
    protected ImageLoadingArgs mArgs = null;

    public ImageLoadingArgs getmArgs() {
        return mArgs;
    }


    public ImageCalcInSampleRunnable(ImageLoadingArgs args) {
        mArgs = args;
    }

    Future mMyTask = null;

    long timeCounter = 0;


    public void run() {
        timeCounter = System.currentTimeMillis();

        if (mArgs.position < mFirstVisibleItem - IMAGE_CANCEL_THERSHOLD
                ||
                mArgs.position > mLastVisibleCount + IMAGE_CANCEL_THERSHOLD) {

            if (firstReturn) {

                firstReturn = false;
            }
            return;
        }

        firstReturn = true;
        boolean ismimeTypeImage = true;
        if (mArgs.mMimeTpe != null && mArgs.mMimeTpe.contains("video")) {
            ismimeTypeImage = false;
        }

        if (mDiskCache.containsKey(mArgs.mImageId)) {


            mArgs.mBitmap = mDiskCache.getBitmap(mArgs.mImageId);

            addBitmapToMemoryCache(ContentUris.parseId(mArgs.mUri), mArgs.mBitmap);
            if (mArgs.mBitmap != null)

                if (!ismimeTypeImage)
                    mArgs.isVideo = true;



        } else {


            if (ismimeTypeImage) {
                try {
                    mArgs.mBitmap = MediaStore.Images.Thumbnails.getThumbnail(mContentResolver, Long.parseLong(mArgs.mImageId),
                            MediaStore.Images.Thumbnails.MINI_KIND, null);

                    mArgs.mBitmap = scaleCenterCrop(mArgs.mBitmap, mImageWidth, mImageWidth, false);

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

                if (mArgs.mBitmap == null) {
                    mArgs.options = ImageManager.decodeInSampledBitmapFromResourceMulti(mArgs.mData, mArgs.mWidth, mArgs.mheight);
                    if (Utils.hasHoneycomb()) {
                        mDiskCache.addInBitmapOptions(mArgs.options);

                        mArgs.mBitmap = BitmapFactory.decodeFile(mArgs.mData, mArgs.options);
                    }else {
                        mArgs.mBitmap = BitmapFactory.decodeFile(mArgs.mData, mArgs.options);
                    }

                    mArgs.mBitmap = scaleCenterCrop(mArgs.mBitmap, mImageWidth, mImageWidth, false);

                }

                if (mArgs.mBitmap != null) {

                    AddBitmapToDiskCache(mArgs.mImageId, mArgs.mBitmap);

                    if (mDiskCache.containsKey(mArgs.mImageId)) {
                        mArgs.mBitmap = mDiskCache.getBitmap(mArgs.mImageId);
                    }

                        addBitmapToMemoryCache(ContentUris.parseId(mArgs.mUri), mArgs.mBitmap);
                } else {
                    try {
                        mArgs.mBitmap = MediaStore.Video.Thumbnails.getThumbnail(mContentResolver, Long.parseLong(mArgs.mImageId),
                                MediaStore.Video.Thumbnails.MINI_KIND, null);
                        mArgs.mBitmap = scaleCenterCrop(mArgs.mBitmap, mImageWidth, mImageWidth, true);

                    } catch (NumberFormatException e) {
                    }
                    if (mArgs.mBitmap != null) {
                        mArgs.isVideo = true;
                        AddBitmapToDiskCache(mArgs.mImageId, mArgs.mBitmap);
                        if (mDiskCache.containsKey(mArgs.mImageId)) {
                            mArgs.mBitmap = mDiskCache.getBitmap(mArgs.mImageId);
                        }
                        addBitmapToMemoryCache(Long.parseLong(mArgs.mImageId), mArgs.mBitmap);
                    }
                }


            } else {
                try {
                    mArgs.mBitmap = MediaStore.Video.Thumbnails.getThumbnail(mContentResolver, Long.parseLong(mArgs.mImageId),
                            MediaStore.Video.Thumbnails.MINI_KIND, null);
                    mArgs.mBitmap = scaleCenterCrop(mArgs.mBitmap, mImageWidth, mImageWidth, true);

                } catch (NumberFormatException e) {
                }
                if (mArgs.mBitmap != null) {
                    mArgs.isVideo = true;
                    AddBitmapToDiskCache(mArgs.mImageId, mArgs.mBitmap);
                    if (mDiskCache.containsKey(mArgs.mImageId)) {
                        mArgs.mBitmap = mDiskCache.getBitmap(mArgs.mImageId);
                    }
                    addBitmapToMemoryCache(Long.parseLong(mArgs.mImageId), mArgs.mBitmap);
                }
            }
        }



        if (mArgs.position > mFirstVisibleItem - IMAGE_CANCEL_THERSHOLD
                &&
                mArgs.position < mLastVisibleCount + IMAGE_CANCEL_THERSHOLD) {

            mArgs.mHandler.sendMessage(mArgs.mHandler.obtainMessage(1,mArgs));

        }

        Log.d("shimi5", "timecount=" + (System.currentTimeMillis() - timeCounter));
        timeCounter = (System.currentTimeMillis() - timeCounter);
        if (timeCounter < 45) {
            try {
                Thread.sleep(45 - timeCounter);

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

        }


    }

    public void cancel() {

    }

    @Override
    public boolean equals(Object obj) {
        if (obj != null && obj instanceof ImageCalcInSampleRunnable) {
            if (mArgs.mUri != null) {
                return mArgs.mUri.equals(((ImageCalcInSampleRunnable) obj).mArgs);
            }
        }
        return false;
    }

    @Override
    public int hashCode() {
        return mArgs.mUri.hashCode();
    }

}

在此之后，处理程序只需将setImageBitmap作为图像视图。任何帮助都非常有帮助

感谢。

Answer 1

在这个问题上一段时间后，我放弃了尝试优化代码，以便更清晰，更流畅地加载图像。

我发现了这个： https://github.com/georgiecasey/android-gallery-library

这是Android开源图库ICS的一个分支。

在此找到了很多见解。

快速图库，快速位图加载

1 个答案: