像 Snapchat-Discover 这样的 Spannable RecyclerView

Question

我正在尝试使用 TwoWayView 库创建一个如下图所示的 spannable recyclerView：https://github.com/lucasr/twoway-view

但我无法获得所需的视图，并且遗漏了空白单元格。

        final SpannableGridLayoutManager.LayoutParams lp = (SpannableGridLayoutManager.LayoutParams) itemView.getLayoutParams();

        //final int span1 = (itemId == 0 || itemId == 3 ? 2 : 1);
        //final int span2 = (itemId == 0 ? 2 : (itemId == 3 ? 3 : 1));

        int span1 = 0; //h
        int span2 = 0; //w

        switch(itemId)
        {
        case 0:
            span1 = 2;
            span2 = 1;
            break;

        case 1:
            span1 = 2;
            span2 = 1;
            break;

        case 2:
            span1 = 2;
            span2 = 1;
            break;

        case 3:
            span1 = 3;
            span2 = 1;
            break;

        case 4:
            span1 = 3;
            span2 = 1;
            break;

        case 5:
            span1 = 4;
            span2 = 3;
            break;

        case 6:
            span1 = 2;
            span2 = 1;
            break;

        case 7:
            span1 = 2;
            span2 = 1;
            break;

        case 8:
            span1 = 2;
            span2 = 1;
            break;

        case 9:
            span1 = 2;
            span2 = 1;
            break;

        case 10:
            span1 = 4;
            span2 = 3;
            break;
        }

        final int colSpan = span2;
        final int rowSpan = span1;

        if (lp.rowSpan != rowSpan || lp.colSpan != colSpan) 
        {
            lp.rowSpan = rowSpan;
            lp.colSpan = colSpan;
            itemView.setLayoutParams(lp);
        }

XML:

<org.lucasr.twowayview.widget.TwoWayView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    style="@style/TwoWayView"
    app:twowayview_layoutManager="ListLayoutManager"/>

参考：

编辑 1 我能够通过在 XML 和以下跨度中将 rowWidth 更改为 12 来解决此问题：

        //PADDING-- left / top / right / bottom
    switch(itemId%11)
    {
    case 0:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 1:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels2, dpAsPixels1, dpAsPixels2, dpAsPixels1);
        break;

    case 2:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 3:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 4:
        span1 = 8;
        span2 = 14;
        //holder.cont_frienddetail.setPadding(dpAsPixels2, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 5:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 6:
        span1 = 6;
        span2 = 10;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels2, dpAsPixels1);
        break;

    case 7:
        span1 = 6;
        span2 = 10;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 8:
        span1 = 8;
        span2 = 14;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels2, dpAsPixels1);
        break;

    case 9:
        span1 = 4;
        span2 = 7;
        ///holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 10:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;
    }

Answer 1

看到这个linkThe link you getting help

Full source code

代码.

MainActivity.java

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;


public class MainActivity extends AppCompatActivity {

    public static final String TYPE_VERTICAL_LIST= "Vertical List";
    public static final String TYPE_HORIZONTAL_LIST= "Horizontal List";
    public static final String TYPE_GRID_VIEW = "Grid View";
    public static final String TYPE_HORIZONTAL_GRID_VIEW_STAGGERED = "HorizontalStaggeredGridView";
    public static final String TYPE_VERTICAL_GRID_VIEW_STAGGERED = "VerticalStaggeredGridView";
    public static final String TYPE = "TYPE";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    attachFragment(TYPE_VERTICAL_LIST);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    /** Return false so that we can capture {@link PlaceholderFragment#onOptionsItemSelected(android.view.MenuItem)} events in {@link PlaceholderFragment} Fragment*/
    return false;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

    switch (item.getItemId()){
        case R.id.action_vertical_list:
        attachFragment(TYPE_VERTICAL_LIST);
        break;
        case R.id.action_horizontal_list:
        attachFragment(TYPE_HORIZONTAL_LIST);
        break;
        case R.id.action_grid_view:
        attachFragment(TYPE_GRID_VIEW);
        break;
        case R.id.action_vertical_grid_view_staggered:
        attachFragment(TYPE_VERTICAL_GRID_VIEW_STAGGERED);
        break;
        case R.id.action_horizontal_grid_view_staggered:
        attachFragment(TYPE_HORIZONTAL_GRID_VIEW_STAGGERED);
        break;
    }

    return super.onOptionsItemSelected(item);
    }


    /** Attach placeholder fragment here and show different kind of RecyclerView flavours eg List or grid based on user selection in the options menu.*/
    private void attachFragment(String type){
    Bundle bundle = new Bundle();
    bundle.putString(TYPE, type);
    PlaceholderFragment placeholderFragment = new PlaceholderFragment();
    placeholderFragment.setArguments(bundle);
    getSupportFragmentManager().beginTransaction().replace(R.id.container, placeholderFragment).commit();
    }
    }

PlaceholderFragment.java

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;


public class PlaceholderFragment extends Fragment {

    private static final String TAG = "PlaceholderFragment";
    /*Number of columns in the grid view*/
    private static final int NUM_OF_COLUMNS = 2;
    /*Total number of items in the RecyclerView*/
    private static final int NUM_OF_ITEMS = 100;
    private ArrayList<DataModel> mDataModels;
    private RecyclerView recyclerView;
    private RecyclerViewAdapter recyclerViewAdapter;
    private int addItemCount = 0;


    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        //Must be set in order to capture menu item click events. If you don't set it, it will not show the menu items set in the Activity holding this fragment.
        setHasOptionsMenu(true);
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        recyclerView = (RecyclerView)rootView.findViewById(R.id.recyclerview);


        RecyclerView.LayoutManager layoutManager = null;
        String type = getArguments().getString(MainActivity.TYPE);
        if( type.equals(MainActivity.TYPE_VERTICAL_LIST)){
            /*LinearLayoutManager to show a vertical list view*/
            layoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false);
        }else if(type.equals(MainActivity.TYPE_HORIZONTAL_LIST)){
            /*LinearLayoutManager to show a horizontal list view*/
            layoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false);
        }else if(type.equals(MainActivity.TYPE_GRID_VIEW)){
             /*LinearLayoutManager to show a grid view. We can specify number of columns in the grid.*/
            layoutManager = new GridLayoutManager(getActivity(), NUM_OF_COLUMNS);

        }else if(type.equals(MainActivity.TYPE_HORIZONTAL_GRID_VIEW_STAGGERED)){
             /*LinearLayoutManager to show a staggered grid view. We can specify number of columns in the grid.*/
            //spanCount:   If orientation is vertical, spanCount is number of columns. If orientation is horizontal, spanCount is number of rows.
            //orientation: StaggeredGridLayoutManager.HORIZONTAL or StaggeredGridLayoutManager.HORIZONTAL
            layoutManager = new StaggeredGridLayoutManager(3/*span count*/, StaggeredGridLayoutManager.HORIZONTAL/* orientation*/);

        }else if(type.equals(MainActivity.TYPE_VERTICAL_GRID_VIEW_STAGGERED)){
             /*LinearLayoutManager to show a staggered grid view. We can specify number of columns in the grid.*/
            //spanCount:   If orientation is vertical, spanCount is number of columns. If orientation is horizontal, spanCount is number of rows.
            //orientation: StaggeredGridLayoutManager.HORIZONTAL or StaggeredGridLayoutManager.HORIZONTAL
            layoutManager = new StaggeredGridLayoutManager(2/*span count*/, StaggeredGridLayoutManager.VERTICAL/* orientation*/);

        }

        recyclerView.setLayoutManager(layoutManager);
        mDataModels = getDataModelList();
        recyclerViewAdapter = new RecyclerViewAdapter(mDataModels, type);

        /*Third party ItemDecoration found from https://gist.github.com/alexfu/0f464fc3742f134ccd1e*/
        RecyclerView.ItemDecoration verticalDivider  = new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL_LIST);
        RecyclerView.ItemDecoration horizontalDivider = new DividerItemDecoration(getActivity(), DividerItemDecoration.HORIZONTAL_LIST);
        recyclerView.addItemDecoration(horizontalDivider);
        recyclerView.addItemDecoration(verticalDivider);

        // this is the default;
        // this call is actually only necessary with custom ItemAnimators
        recyclerView.setItemAnimator(new DefaultItemAnimator());

        recyclerView.setAdapter(recyclerViewAdapter);
        return rootView;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()){
            case R.id.action_add_item:
                addItem();
                break;
            case R.id.action_delete_item:
                deleteItem();
                break;

        }

        return super.onOptionsItemSelected(item);
    }

    /** Creates and returns the data items to be shown in the Recycler View*/
    private ArrayList<DataModel> getDataModelList(){
        ArrayList<DataModel> dataModels = new ArrayList<>();

        for (int i = 0; i < NUM_OF_ITEMS; i++) {
            dataModels.add(new DataModel("Title:"+i));
        }

        return dataModels;
    }


    /** Adds a single item in the existing list*/
    private final void addItem(){
        //Adding item at top second position(i.e. at index 1).
        mDataModels.set(1, new DataModel("Added Item "+String.valueOf(++addItemCount)));
        //See for similar methods to know more item insertion options
        recyclerViewAdapter.notifyItemInserted(1);
    }

    /** Deletes a single item from the existing list*/
    private void deleteItem(){
        //Removing top item
        mDataModels.remove(0);
        //See for similar methods to know more item removing options
        recyclerViewAdapter.notifyItemRemoved(0);
    }

}

ListItemViewHolder.java

public class ListItemViewHolder extends ViewHolder {

ImageView imgView;
TextView title;

public ListItemViewHolder(View itemView) {
    super(itemView);
    title = (TextView) itemView.findViewById(R.id.textview_title);
    imgView = (ImageView) itemView.findViewById(R.id.imageview_icon);
 }
 }

DividerItemDecoration.java

 import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;


public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDivider;

    private int mOrientation;

    public DividerItemDecoration(Context context, int orientation) {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

    public void setOrientation(int orientation) {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }

    public void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    public void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}

RecyclerViewAdapter.java

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;

public class RecyclerViewAdapter extends RecyclerView.Adapter<ListItemViewHolder> {


    private ArrayList<DataModel> mDataModels;
    private String mType;

    public RecyclerViewAdapter(ArrayList<DataModel> mDataModels, String mType) {
        this.mDataModels = mDataModels;
        this.mType = mType;
    }


    @Override
    public ListItemViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_recycler_view, parent, false);
        return new ListItemViewHolder(itemView);
    }


    @Override
    public void onBindViewHolder(ListItemViewHolder holder, int position) {
        DataModel model = mDataModels.get(position);
        holder.title.setText(model.getTitle());
        if(position % 2 == 0){
            if(mType.equals(MainActivity.TYPE_VERTICAL_GRID_VIEW_STAGGERED)){
                holder.imgView.setImageResource(R.drawable.lollipop);
            }else{
                holder.imgView.setImageResource(R.drawable.lollipop_h1);
            }

        }else if(position % 3 == 0){
            if(mType.equals(MainActivity.TYPE_VERTICAL_GRID_VIEW_STAGGERED)){
                holder.imgView.setImageResource(R.drawable.lollipop1);
            }else{
                holder.imgView.setImageResource(R.drawable.lollipop_h2);
            }
        }else{
            if(mType.equals(MainActivity.TYPE_VERTICAL_GRID_VIEW_STAGGERED)){
                holder.imgView.setImageResource(R.drawable.lollipop2);
            }else{

                holder.imgView.setImageResource(R.drawable.lollipop_h3);
            }
        }
    }


    @Override
    public int getItemCount() {
        return mDataModels.size();
    }
}

DataModel.java

public class DataModel {

    private String title;

    public DataModel(String title) {
        this.title = title;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

activity_main.xml

  <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    tools:ignore="MergeRootFrame" />

fragment_main.xml

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity"
        tools:listitem="@layout/item_recycler_view"
        />

</RelativeLayout>

item_recycler_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_vertical"
    android:padding="8dp"
    android:background="@android:color/holo_green_dark">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/imageview_icon"
        android:src="@drawable/lollipop"
        android:scaleType="centerCrop"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:id="@+id/textview_title"
        android:background="@android:color/darker_gray"/>
</LinearLayout>

Answer 2

想象一下您的示例图像并将每个单元格的垂直边界延伸到整个屏幕。如果这样做，您会看到有六列。这就是将解决您的问题的洞察力。

现在您可以使用常规 RecyclerView 和 GridLayoutManager 来完成此操作，而不必依赖于修复其 GitHub 库中的所有错误。

创建一个包含 6 列的 GridLayoutManager，然后指定一个自定义 SpanSizeLookup，这将使您的单元格具有不同的宽度。

在您的示例图像中，第一行中的三个单元格各跨越 2 列。第二行中两个较大的单元格各跨越 3 列。左下方的单元格跨越 4 列。

所以现在您所要做的就是创建一个 SpanSizeLookup 来设置正确的宽度。

    // Create a grid layout with 6 columns
    // (least common multiple of 2 and 3)
    GridLayoutManager layoutManager = new GridLayoutManager(this, 6);

    layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {

            int widthClass = determineWidth(position) // TODO here you figure out what the cell width should be

            switch (widthClass) {
            case SMALL:
                return 2;   // fits 3 per row

            case MEDIUM:
                return 3;   // fits 2 per row

            case LARGE:     // fits 2 per row, one LARGE and one SMALL
                return 4;

            default:
                throw new IllegalStateException("don\'t know about widthClass " + widthClass);
            }
        }
    });

您可以查看我对类似问题的原始回答here。

Answer 3

我能够通过在 XML 和以下范围内将 rowWidth 更改为 12 来解决此问题：

        //PADDING-- left / top / right / bottom
switch(itemId%11)
{
case 0:
    span1 = 4;
    span2 = 7;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;

case 1:
    span1 = 4;
    span2 = 7;
    //holder.cont_frienddetail.setPadding(dpAsPixels2, dpAsPixels1, dpAsPixels2, dpAsPixels1);
    break;

case 2:
    span1 = 4;
    span2 = 7;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;

case 3:
    span1 = 4;
    span2 = 7;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;

case 4:
    span1 = 8;
    span2 = 14;
    //holder.cont_frienddetail.setPadding(dpAsPixels2, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;

case 5:
    span1 = 4;
    span2 = 7;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;

case 6:
    span1 = 6;
    span2 = 10;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels2, dpAsPixels1);
    break;

case 7:
    span1 = 6;
    span2 = 10;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;

case 8:
    span1 = 8;
    span2 = 14;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels2, dpAsPixels1);
    break;

case 9:
    span1 = 4;
    span2 = 7;
    ///holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;

case 10:
    span1 = 4;
    span2 = 7;
    //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
    break;
}

像 Snapchat-Discover 这样的 Spannable RecyclerView

Spannable RecyclerView like Snapchat-Discover

android

snapchat

android-recyclerview