android recyclerview显示本地图片,android-如何在recyclerview中加载大量图像？

我有一个活动,允许用户选择大约500张图像,然后转到下一个活动,这些图像将在RecyclerView中填充,我应该如何使其全部正常工作,以实现流畅的用户体验和更好的性能.

目前,我正在使用意图将图像作为位图传递.

我正在使用photopicker库进行照片选择,这里允许用户选择多个图像,所有选定图像的文件路径都存储在字符串Arraylist中,该字符串在活动的onActivityResult中返回,我正在存储结果在mUserSelectedPhotos名为string arraylist的下面是一些代码供参考.

PhotoPickingActivity.java

mPickImagesButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

PhotoPicker.builder()

.setPhotoCount(200)

.setShowCamera(true)

.setShowGif(true)

.setPreviewEnabled(true)

.start(ChoosePhotoBookImagesActivity.this, PhotoPicker.REQUEST_CODE);

}

});

@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {

super.onActivityResult(requestCode, resultCode, data);

if (resultCode == RESULT_OK && requestCode == PhotoPicker.REQUEST_CODE) {

if (data != null) {

mUserSelectedPhotos =

data.getStringArrayListExtra(PhotoPicker.KEY_SELECTED_PHOTOS);

}

}

}

单击下一个按钮时,用户选择的图像字符串数组列表将通过意图传递到下一个活动.

PhotoPickingActivity.java

mNextButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

Intent intent = new Intent(PhotoPickingActivity.this, PhotoBookListViewActivity.class);

intent.putStringArrayListExtra("USER_SELECTED_IMAGES", mUserSelectedPhotos);

startActivity(intent);

}

});

在包含recyclerview的下一个活动中,我正在此活动中接收发送的意图,并且在意图中接收的数据是字符串的数组列表,其中包含用户在上一个活动中选择的图像的文件路径.

PhotoBookListViewActivity.java

Intent intent = getIntent();

mReceivedImageList = intent.getStringArrayListExtra("USER_SELECTED_IMAGES");

我正在阅读mReceivedImageList并将文件路径转换为位图,并将其存储在新的位图arraylist中.

PhotoBookListViewActivity.java

final ArrayList bitmapImages = new ArrayList();

for (int i = 0; i < mImageList.size(); i++) {

mPhotoUrl = mImageList.get(i).toString();

Bitmap myBitmap = BitmapFactory.decodeFile(mPhotoUrl);

bitmapImages.add(new PhotoBookViewModel(myBitmap));

}

将bitmapImages arraylist(这是位图图像的列表)传递给适配器.

PhotoBookListViewActivity.java

mPhotoBookViewAdapter = new PhotoBookViewAdapter(PhotoBookListViewActivity.this, bitmapImages);

mPhotoBookViewRecyclerView.setAdapter(mPhotoBookViewAdapter);

mPhotoBookViewRecyclerView.setLayoutManager(new LinearLayoutManager(PhotoBookListViewActivity.this, LinearLayoutManager.VERTICAL, false));

PhotoBookViewModel.java

import android.graphics.Bitmap;

public class PhotoBookViewModel {

private Bitmap mImageRes;

public PhotoBookViewModel(Bitmap imageRes) {

this.mImageRes = imageRes;

}

public Bitmap getImageRes() {

return mImageRes;

}

}

PhotoBookViewAdapter.java

public class PhotoBookViewAdapter extends RecyclerView.Adapter {

private ArrayList mData;

private LayoutInflater mLayoutInflater;

private View mImageItemView;

private ArrayList mSelectedPhotos;

private Bitmap mBitmap;

private Context mContext;

public class PhotoViewHolder extends RecyclerView.ViewHolder {

private ImageView mImageView;

public PhotoViewHolder(@NonNull View itemView) {

super(itemView);

mImageView = itemView.findViewById(R.id.imageview);

}

public void setData(PhotoBookViewModel currentObj) {

this.mImageView.setImageBitmap(currentObj.getImageRes());

}

}

public PhotoBookViewAdapter(Context context, ArrayList selectedPhotos) {

this.mContext = context;

this.mSelectedPhotos = selectedPhotos;

mBitmap = BitmapFactory.decodeFile (mSelectedPhotos.get(0).toString());

}

public PhotoBookViewAdapter(Context context, ArrayList mData) {

this.mData = mData;

mLayoutInflater = LayoutInflater.from(context);

}

@NonNull

@Override

public PhotoViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {

mImageItemView = LayoutInflater.from(viewGroup.getContext())

.inflate(R.layout.photo_book_view_image_item, viewGroup, false);

PhotoViewHolder photoViewHolder = new PhotoViewHolder(mImageItemView);

mContext = viewGroup.getContext();

return photoViewHolder;

}

@Override

public void onBindViewHolder(@NonNull PhotoViewHolder photoViewHolder, int position) {

PhotoBookViewModel currentObj = mData.get(position);

photoViewHolder.setData(currentObj);;

}

@Override

public int getItemCount() {

return mData.size();

}

}