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RecyclerView:带header的grid

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RecyclerView是一个高度可定制性的View
本文将使用RecyclerView实现带header的grid

为了用RecyclerView创建一个带header的grid:

1,定义一个具有两种view类型的adapter,一个为header,一个为普通item。

2,nflate一个header,把它传递给adapter。

3,重写GridLayoutManager中的setSpanSizeLookup,在header所处的位置返回和span count (列数)相等的 span size。

import java.util.ArrayList;
import java.util.List;

import com.example.test.R;
import com.widget.view.HeaderAdapter.ViewHolder;

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

/**
 * 为了用RecyclerView创建一个带header的grid:

	1,定义一个具有两种view类型的adapter,一个为header一个为普通item。
	
	2,inflate一个header,把它传递给adapter。
	
	3,重写GridLayoutManager中的setSpanSizeLookup,在header所处的位置返回和span count(列数)相等的 span size。
 * @author Administrator
 *
 */
public class HeaderAdapter extends RecyclerView.Adapter<ViewHolder> {

	private static final int ITEM_VIEW_TYPE_HEADER = 0;
	private static final int ITEM_VIEW_TYPE_ITEM = 1;

	private final View header;
	private final List<String> labels;

	public HeaderAdapter(View header, int count) {
		if (header == null) {
			throw new IllegalArgumentException("header may not be null");
		}
		this.header = header;
		this.labels = new ArrayList<String>(count);
		for (int i = 0; i < count; ++i) {
			labels.add(String.valueOf(i));
		}
	}

	public boolean isHeader(int position) {
		return position == 0;
	}

	@Override
	public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
		if (viewType == ITEM_VIEW_TYPE_HEADER) {
			return new ViewHolder(header);
		}
		View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
		return new ViewHolder(view);
	}

	@Override
	public void onBindViewHolder(final ViewHolder holder, final int position) {
		if (isHeader(position)) {
			return;
		}
		final String label = labels.get(position - 1); // Subtract 1 for header
		holder.textView.setText(label);
	}

	@Override
	public int getItemViewType(int position) {
		return isHeader(position) ? ITEM_VIEW_TYPE_HEADER : ITEM_VIEW_TYPE_ITEM;
	}

	@Override
	public int getItemCount() {
		return labels.size() + 1;
	}

	class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
		public TextView textView;

		public ViewHolder(View itemView) {
			super(itemView);
			if (onItemClickLitener != null){
				itemView.setOnClickListener(this);
            }
			textView = (TextView) itemView.findViewById(R.id.item_0);
		}

		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			onItemClickLitener.onItemClick(v, getLayoutPosition());//getPosition()被废弃了
		}
		
	}
	
	private static OnItemClickLitener onItemClickLitener;
	
	public void setOnItemClickLitener(OnItemClickLitener onItemClickLitener) {
		this.onItemClickLitener = onItemClickLitener;
	}
	
	public interface OnItemClickLitener {
		void onItemClick(View view, int position);
	}

}


recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
View header = LayoutInflater.from(this).inflate(R.layout.header_view, recyclerView, false);
			final HeaderAdapter adapter = new HeaderAdapter(header, 30);
			adapter.setOnItemClickLitener(new HeaderAdapter.OnItemClickLitener() {
				
				@Override
				public void onItemClick(View view, int position) {
					// TODO Auto-generated method stub
					if(adapter.isHeader(position)){
						Toast.makeText(context, "header clicked", Toast.LENGTH_SHORT).show();
					}else{
						Toast.makeText(context, "header item "+(position-1), Toast.LENGTH_SHORT).show();
					}
				}
			});
			
        	final GridLayoutManager manager = new GridLayoutManager(this, 3);
        	manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
				@Override
				public int getSpanSize(int position) {
					return adapter.isHeader(position) ? manager.getSpanCount() : 1;
				}
			});
        	recyclerView.setLayoutManager(manager);
        	
			recyclerView.setAdapter(adapter);


具体描述看原帖,我只是稍稍改了一下
http://www.open-open.com/lib/view/open1437662138631.html
如果你觉得使用RecyclerView添加Header比较烦,那没办法,就使用这个HeaderGridView类吧
RecyclerView 必知必会
http://mp.weixin.qq.com/s/CzrKotyupXbYY6EY2HP_dA
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