Android_RecyclerView多布局 Listview多布局 代码实现

前言

每个人每天都会在浏览器上看一些最新的新闻，作为一个IT程序员你们会发现，她们的布局排版都是有区别的，有时候同一个样式的条目有4、5条 界面一样，下面又出现1 条不一样的条目，这样的效果是不是很美观，这在Android称为多布局，下面来简单实现一下，大概理解下

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使用

1.RecyclerView

利用Adapter的getItemViewType()方法返回不同的VIEW_TYPE，利用求末取余的算法获取到当前位置的条目，然后在onCreateViewHolder中设置对应的ViewHolder 。

    final int VIEW_TYPE = 3;
    final int TYPE_1    = 0;
    final int TYPE_2    = 1;
    final int TYPE_3    = 2;
 /**
     * 获取每个位置的View
     *
     * @param position
     * @return
     */
    @Override
    public int getItemViewType(int position) {
        int p = position % VIEW_TYPE;
        if (p == 0) {
            return TYPE_1;
        } else if (p == 1) {
            return TYPE_2;
        } else {
            return TYPE_3;
        }

    }

   @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (viewType == TYPE_1) {
            View view = View.inflate(mContext, R.layout.adapter, null);
            return new MyViewHolder(view);
        } else if (viewType == TYPE_2) {
            View view2 = View.inflate(mContext, R.layout.adapter2, null);

            return new MyViewHolder2(view2);
        } else {
            View view3 = View.inflate(mContext, R.layout.adapter3, null);
            return new MyViewHolder3(view3);
        }

    }

这个方法是给每一个ViewHolder设置数据

@Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        MyViewHolder holder1 = null;
        MyViewHolder2 holder2 = null;
        MyViewHolder3 holder3 = null;
        if (holder instanceof MyViewHolder) {
            holder1 = (MyViewHolder) holder;
        } else if (holder instanceof MyViewHolder2) {
            holder2 = (MyViewHolder2) holder;

        } else {
            holder3 = (MyViewHolder3) holder;

        }
    }

完整代码：

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    Context       mContext;
    List<Integer> mList;
    final int VIEW_TYPE = 3;
    final int TYPE_1    = 0;
    final int TYPE_2    = 1;
    final int TYPE_3    = 2;


    public MyAdapter(Context context, List<Integer> list) {
        mContext = context;
        mList = list;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (viewType == TYPE_1) {
            View view = View.inflate(mContext, R.layout.adapter, null);
            return new MyViewHolder(view);
        } else if (viewType == TYPE_2) {
            View view2 = View.inflate(mContext, R.layout.adapter2, null);

            return new MyViewHolder2(view2);
        } else {
            View view3 = View.inflate(mContext, R.layout.adapter3, null);
            return new MyViewHolder3(view3);
        }

    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        MyViewHolder holder1 = null;
        MyViewHolder2 holder2 = null;
        MyViewHolder3 holder3 = null;
        if (holder instanceof MyViewHolder) {
            holder1 = (MyViewHolder) holder;
        } else if (holder instanceof MyViewHolder2) {
            holder2 = (MyViewHolder2) holder;

        } else {
            holder3 = (MyViewHolder3) holder;

        }
    }


    /**
     * 获取每个位置的View
     *
     * @param position
     * @return
     */
    @Override
    public int getItemViewType(int position) {
        int p = position % VIEW_TYPE;
        if (p == 0) {
            return TYPE_1;
        } else if (p == 1) {
            return TYPE_2;
        } else {
            return TYPE_3;
        }

    }


    @Override
    public int getItemCount() {
        if (mList != null) {
            return mList.size();
        }
        return 0;
    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        public MyViewHolder(View itemView) {
            super(itemView);
        }
    }

    class MyViewHolder2 extends RecyclerView.ViewHolder {
        public MyViewHolder2(View itemView) {
            super(itemView);
        }
    }

    class MyViewHolder3 extends RecyclerView.ViewHolder {
        public MyViewHolder3(View itemView) {
            super(itemView);
        }
    }
}

2.ListView

ListView比RecyclerView多了getViewTypeCount() 布局数量 的方法

  //  总共有几种布局
    @Override
    public int getViewTypeCount() {
        return VIEW_TYPE;
    }

完整代码：

public class MyAdapter2 extends BaseAdapter {
    private List<Integer> list;
    private Context       ctx;
    final int VIEW_TYPE = 3;
    final int TYPE_1    = 0;
    final int TYPE_2    = 1;
    final int TYPE_3    = 2;

    public MyAdapter2(List<Integer> list, Context ctx) {
        super();
        this.list = list;
        this.ctx = ctx;
    }

    //  获取Item的View的类型
    @Override
    public int getItemViewType(int position) {
        int i = position % VIEW_TYPE;
        if (i == 0) {
            return TYPE_1;
        } else if (i == 1) {
            return TYPE_2;
        } else {
            return TYPE_3;
        }
    }

    //  总共有几种布局
    @Override
    public int getViewTypeCount() {
        return VIEW_TYPE;
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }


    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        MyViewHolder holder1 = null;
        MyViewHolder2 holder2 = null;
        MyViewHolder3 holder3 = null;
        int type = getItemViewType(position);
        if (convertView == null) {
            //设置布局和找ID
            switch (type) {
                case TYPE_1:
                    convertView = View.inflate(ctx, R.layout.adapter, null);
                    holder1 = new MyViewHolder(convertView);
                    convertView.setTag(holder1);
                    break;
                case TYPE_2:
                    convertView = View.inflate(ctx, R.layout.adapter2, null);
                    holder2 = new MyViewHolder2(convertView);
                    convertView.setTag(holder2);
                    break;
                case TYPE_3:
                    convertView = View.inflate(ctx, R.layout.adapter3, null);
                    holder3 = new MyViewHolder3(convertView);
                    convertView.setTag(holder3);
                    break;
            }
        } else {
            //设置复用
            switch (type) {
                case TYPE_1:
                    holder1 = (MyViewHolder) convertView.getTag();
                    break;

                case TYPE_2:
                    holder2 = (MyViewHolder2) convertView.getTag();
                    break;
                case TYPE_3:
                    holder3 = (MyViewHolder3) convertView.getTag();
                    break;
            }
        }
        //设置数据
        switch (type) {
            case TYPE_1:

                break;

            case TYPE_2:

                break;
            case TYPE_3:

                break;
        }
        return convertView;
    }

    private class MyViewHolder {
        public MyViewHolder(View convertView) {

        }
    }

    private class MyViewHolder2 {
        public MyViewHolder2(View convertView) {

        }
    }

    private class MyViewHolder3 {
        public MyViewHolder3(View convertView) {

        }
    }
}

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MainActivity.java

public class MainActivity extends AppCompatActivity {
    RecyclerView mRecy;
    ListView     mLv;
    List<Integer> mList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initList();
        initView();

    }

    private void initList() {
        for (int i = 0; i < 100; i++) {
            mList.add(i);
        }
    }

    private void initView() {
        mRecy = findViewById(R.id.mRecy);
        mLv = findViewById(R.id.mLv);
        //        mRecy.setLayoutManager(new LinearLayoutManager(this));
        //        mRecy.setAdapter(new MyAdapter(this, mList));
        mLv.setAdapter(new MyAdapter2(mList,this));
    }
}

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效果图：