问题
So this is what im trying to achieve, is a recycler view with a 3x3 grid and when items exceed the 3x3 ,they spill into the next screen/page.
So ive used a recyclerview with horizontal scrolling
This is what ive achieved so far
and my current code does work when the count of items is 7 and above.
When the count is below 7 im facing issues with which i need help.
Listing my issues as questions
Question 1:
Why is the recyclerview items populated in vertical fashion?
1 4
2 5
3 6
I've set my recyclerview to scroll horizontally,
new GridLayoutManager(this, span, GridLayoutManager.HORIZONTAL, false);
Question 2:
When my item count is 6 , how do i avoid the space between the rows?
Question 3:
When my items are say 4 ,i want to show my items as
1 2 3
4
or
1 3 4
2
currently it shows as
If i set span to 1,ill have the grid as
1 2 3 4
causing 4 to go off-screen like so
1 2 3 |4
which i want to avoid.
==============
Code ive used
Layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="88dp"
android:layout_height="88dp"
android:gravity="center"
android:layout_margin="10dp"
android:background="@drawable/border"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:background="@android:color/darker_gray"
android:orientation="vertical"
android:weightSum="1">
<TextView
android:id="@+id/lblTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:text="TEST"
android:textSize="20sp" />
<TextView
android:id="@+id/lblDesc"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/lblTitle"
android:layout_centerHorizontal="true"
android:text="TEST"
android:textSize="13sp" />
</RelativeLayout>
</LinearLayout>
Adapter:
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.CustomViewHolder> {
Context ctx;
List<String> listText;
public class CustomViewHolder extends RecyclerView.ViewHolder {
TextView lblText;
public CustomViewHolder(View view) {
super(view);
view.setClickable(true);
lblText = (TextView) view.findViewById(R.id.lblDesc);
}
}
public RecyclerViewAdapter(Context ctx, List<String> listText) {
this.ctx = ctx;
this.listText = listText;
}
@Override
public RecyclerViewAdapter.CustomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.recycler_child_row, parent, false);
return new CustomViewHolder(itemView);
}
@Override
public void onBindViewHolder(CustomViewHolder holder, int position) {
holder.lblText.setText(listText.get(position));
}
@Override
public int getItemCount() {
return listText.size();
}
}
Activity
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerTest;
private GridLayoutManager gridLayoutRecyclerview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerTest = (RecyclerView) findViewById(R.id.recyclerTest);
List<String> items = Arrays.asList("1", "2", "3", "4");
/*List<String> items = Arrays.asList("1", "2", "3", "4", "5");*/
/*List<String> items = Arrays.asList("1", "2", "3", "4", "5", "6", "7");*/
/*List<String> items = Arrays.asList("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11");*/
/*List<String> items = Arrays.asList("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13","14");*/
/*List<String> items = Arrays.asList("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11","12","13","14","15");*/
/*List<String> items = Arrays.asList("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11","12","13","14","15","16","17");*/
int span = 0;
if (items.size() <= 3) {
span = 1;
} else if (items.size() <= 6) {
span = 2;
} else {
span = 3;
}
gridLayoutRecyclerview = new GridLayoutManager(this, span, GridLayoutManager.HORIZONTAL, false);
recyclerTest.setLayoutManager(gridLayoutRecyclerview);
SnapHelper snapHelper = new GravitySnapHelper(Gravity.START);
snapHelper.attachToRecyclerView(recyclerTest);
recyclerTest.setAdapter(new RecyclerViewAdapter(this, items));
}
}
回答1:
Why is the recyclerview items populated in vertical fashion?
1 4 2 5 3 6
A RecyclerView is intended for Lists that scroll. If you have a horizontal layout, it will fill the first column, followed by the second, then the third, etc. After all, that's how we would expect a list to work. And that's why the "numbering is off". It starts with the first column, going on to the next once it is filled.
When my item count is 6 , how do i avoid the space between the rows?
I don't know your setup, but I'm guessing your recyclerviews height is set to match_parent, so it's probably just using up all the available height. wrap_content height for the recyclerview might help.
When my items are say 4 ,i want to show my items as
1 2 3 4or
1 3 4 2
Again, see above, that's not how a RecyclerView works. It will always fill the columns one by one, and not start with a row. 4 Items with a column count of 2 will always fill the first columns first, like below.
1 3
2 4
A RecyclerView might not fit all your needs. You could switch to a vertical grid layout with 3 columns with less than 9 items. That way it would not scroll horizontally, and it would even fill the views up like you described. For more than 9 items you'd still show the horizontal version and have it scroll.
What you're actually describing is a custom layout: You want a view that behaves in a specific fashion. You could have a look on how to create your own ViewGroup and use that to lay out all the views however you like. Unless you want to show long lists, that might be a good alternative option.
来源：https://stackoverflow.com/questions/46206283/recyclerview-horizontal-span-and-spacing-issues