Firebase:将随机数据从Firebase中提取到RecyclerView(android) [英] Firebase: Pull random data from Firebase to RecyclerView (android)
问题描述
我想每次刷新活动时把随机itens里面的Recyclerview。
如何将随机数据放入RecyclerView? Firebase没有特殊的随机查询。有没有其他方法可以做到这一点?
以下是我的代码:
mDatabase = FirebaseDatabase.getInstance()。getReference()。child(Category);
query = mDatabase.limitToFirst(6);
@Override
保护无效populateViewHolder(最终CategoryViewHolder viewHolder,类别模型,int位置){
viewHolder.setImage(getApplicationContext(),model .getImagem());
viewHolder.mView.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
});
}
};
mImagesList.setAdapter(firebaseRecyclerAdapter);
$ b $ / code $ / pre
$ b $ p我的适配器
public static class CategoryViewHolder extends RecyclerView.ViewHolder {
View mView;
public CategoryViewHolder(View itemView){
super(itemView);
mView = itemView;
public void setImage(Context ctx,String image1){
ImageView image =(ImageView)mView.findViewById(R.id.photo);
Picasso.with(ctx).load(image1).into(image);
$ b $ / code $ / pre
解决方案我建议你也在你的Model类中添加另一个变量。有点像身份证。你随机存储 Long
值。 (例如从0到15)。
然后创建一个方法,它将生成一个随机值(可以说方法的名字是 generateRandom()
)。这样,当你想获得随机数据时,你可以使用你的查询:
$ p $ query = mDatabase.orderByChild ID)startAt(generateRandom())limitToFirst(6)。。
I made a query to pull only 6 itens from database inside a RecyclerView, but at this time I can only orderByChild, limitToFirst or last. Everything is working fine but...
I'd like to put Random itens inside the Recyclerview every time I refresh the activity.
How can I put random data inside RecyclerView? Firebase does not have a special Random query. Is there any other way to do it?
Here is my code:
mDatabase = FirebaseDatabase.getInstance().getReference().child("Category");
query = mDatabase.limitToFirst(6);
@Override
protected void populateViewHolder(final CategoryViewHolder viewHolder, Category model, int position) {
viewHolder.setImage(getApplicationContext(), model.getImagem());
viewHolder.mView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
});
}
};
mImagesList.setAdapter(firebaseRecyclerAdapter);
}
My adapter:
public static class CategoryViewHolder extends RecyclerView.ViewHolder {
View mView;
public CategoryViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setImage(Context ctx, String image1) {
ImageView image = (ImageView) mView.findViewById(R.id.photo);
Picasso.with(ctx).load(image1).into(image);
}
}
解决方案 I suggest you also add another variable to your Model class. Something like an "id". And you store random Long
values in it. (From 0 to 15 for example).
And then create a method that will generate a random value (lets say the method's name is generateRandom()
). This way, when you want to get the random data, you can use your query like this:
query = mDatabase.orderByChild("id").startAt(generateRandom()).limitToFirst(6);
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