RecyclerView中实现addHeaderView，addFooterView功能

RecyclerView作为ListView的替代者有着较好的性能提升，但是有些ListVIew的常用功能却没有提供比如addHeaderView，addFooterView；

作为替代方案，可以通过自定义的Adapter来实现addHeaderView，addFooterView功能，代码如下：

public class HeaderAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
String[] data;

public HeaderAdapter(String[] data) {
this.data = data;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_ITEM) {
//inflate your layout and pass it to view holder
return new VHItem(null);
} else if (viewType == TYPE_HEADER) {
//inflate your layout and pass it to view holder
return new VHHeader(null);
}

throw new RuntimeException("there is no type that matches the type " + viewType + " + make sure your using types correctly");
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof VHItem) {
String dataItem = getItem(position);
//cast holder to VHItem and set data
} else if (holder instanceof VHHeader) {
//cast holder to VHHeader and set data for header.
}
}

@Override
public int getItemCount() {
return data.length + 1;
}

@Override
public int getItemViewType(int position) {
if (isPositionHeader(position))
return TYPE_HEADER;

return TYPE_ITEM;
}

private boolean isPositionHeader(int position) {
return position == 0;
}

private String getItem(int position) {
return data[position - 1];
}

class VHItem extends RecyclerView.ViewHolder {
TextView title;

public VHItem(View itemView) {
super(itemView);
}
}

class VHHeader extends RecyclerView.ViewHolder {
Button button;

public VHHeader(View itemView) {
super(itemView);
}
}
}