Android RecyclerView添加Header头部

Android RecyclerView不像以前的ListView那样直接添加头部，如果要给RecyclerView增加头部，则需要自己写或者使用第三方开源项目。

RecyclerViewHeader是github上的一个开源项目，旨在为Android RecyclerView增加头部，其在github上的项目主页是：

RecyclerViewHeader使用相对比较简单，写一个例子。

注意RecyclerViewHeader的布局文件写法：

上层Java代码：

package zhangphil.app;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;import com.bartoszlipinski.recyclerviewheader2.RecyclerViewHeader;public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);        LinearLayoutManager layoutManager = new LinearLayoutManager(this);        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);        recyclerView.setLayoutManager(layoutManager);        ItemAdapter adapter = new ItemAdapter();        recyclerView.setAdapter(adapter);        //添加RecyclerView头部        RecyclerViewHeader header = (RecyclerViewHeader) findViewById(R.id.header);        header.attachTo(recyclerView);    }    private class ItemViewHolder extends RecyclerView.ViewHolder {        public TextView text;        public ItemViewHolder(View itemView) {            super(itemView);            text = (TextView) itemView.findViewById(android.R.id.text1);        }    }    private class ItemAdapter extends RecyclerView.Adapter
    
      {        @Override        public ItemViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {            View view = View.inflate(parent.getContext(), android.R.layout.simple_list_item_1, null);            ItemViewHolder holder = new ItemViewHolder(view);            return holder;        }        @Override        public void onBindViewHolder(ItemViewHolder holder, int position) {            holder.text.setText(String.valueOf(position));        }        @Override        public int getItemCount() {            return 20;        }    }}
    

代码运行结果：