让用户等待活动完成加载

Question

大家好，我正在做一个从firestore检索数据的项目，其中一些包含图像的URL。当我启动应用程序时，我注意到加载图像时出现了延迟。所以我想了想我在Facebook应用程序中看到的情况，当加载一个显示带有一些动画的视图的图像时，通知用户该应用程序仍在后台加载，请提供任何帮助。

这就是我检索数据的方式

PostsAdapter=new FirestoreRecyclerAdapter<docs,PostsViewHolder>(allPosts) {
@NonNull
@Override
public PostsViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view= 
LayoutInflater.from(parent.getContext()).inflate(R.layout.single_post,parent,false);
return new PostsViewHolder(view);
}
@Override
protected void onBindViewHolder(@NonNull final PostsViewHolder holder, int position, @NonNull final docs model) {

holder.postTitle.setText(model.getTitle());
holder.postImage.setText(model.getPostimage());
holder.image_1.setText(model.getImage_1());
holder.image_2.setText(model.getImage_2());
holder.content_1.setText(model.getContent_1());
holder.content_2.setText(model.getContent_2());
holder.Date.setText(model.getDate());
holder.postId.setAnimation(AnimationUtils.loadAnimation(getContext(),R.anim.item_animation_fall_down));
holder.singlePostCard.setAnimation(AnimationUtils.loadAnimation(getContext(),R.anim.slide_right));
holder.titleLayout.setAnimation(AnimationUtils.loadAnimation(getContext(),R.anim.slide_up));

Glide.with(requireContext())
.load(model.getPostimage())
.error(R.drawable.error_uom)
.placeholder(R.drawable.ic_account)

.into(holder.spImage);
holder.itemView.playSoundEffect(SoundEffectConstants.CLICK);
holder.itemView.setOnClickListener(v -> {
Intent intent = new Intent(v.getContext(), full_content.class);

vu=v;
holder.itemView.playSoundEffect(0);
intent.putExtra("postImage",model.getPostimage());
intent.putExtra("postTitle",model.getTitle());
intent.putExtra("content_1",model.getContent_1());
intent.putExtra("content_2",model.getContent_2());
intent.putExtra("image_1",model.getImage_1());
intent.putExtra("image_2",model.getImage_2());
intent.putExtra("date",model.getDate());

v.getContext().startActivity(intent);
});
}
};

Answer 1

您可以添加"ProgressBar"；您的"；single_post.xml"；文件，然后在您的ViewHolder类(PostViewHolder(上引用它，然后最后一步是在"；onBindViewHolder"；方法

single_post.xml

<ProgressBar
android:id="@+id/imageProgressBar"
android:layout_width="match_parent"
android:layout_height="100dp"
android:visibility="visible" />

PostViewHolder

ProgressBar imgProgressBar = (ProgressBar) findViewById(R.id.imageProgressBar);

OnBindViewHolder方法

Glide.with(requireContext())
.load(model.getPostimage())
.listener(new RequestListener<Drawable>() {
@Override
public boolean onLoadFailed(@Nullable GlideException e, Object model, Target<Drawable> target, boolean isFirstResource) {
holder.imgProgressBar.setVisibility(View.GONE);
return false;
}
@Override
public boolean onResourceReady(Drawable resource, Object model, Target<Drawable> target, DataSource dataSource, boolean isFirstResource) {
holder.imgProgressBar.setVisibility(View.GONE);
return false;
}
})
.error(R.drawable.error_uom)
.placeholder(R.drawable.ic_account)