之前看一些APP时,发现首页布局大多很复杂,当时就在想这些复杂的布局时直接使用ListView或者RecyclerView
用不同的条目类型实现的,还是用ScrollView进行嵌套实现的呢?后来发现这两种其实都可以,只不过后来看到了
一篇博客才觉得用RecyclerView实现更加方便,用起来也更加舒爽!这篇博客就是liaoinstan大神的,地址我贴在
下面,大家可以去看看,这里我就把我使用的他的第二种方法贴出来进行展示.
liaoinstan 地址:http://blog.youkuaiyun.com/liaoinstan/article/details/52671101
这种方法主要是针对于GridLayoutManager网格布局管理器来进行设置的,因为GridLayoutManager可以设置 列数,而我们可以根据不同条目所占列数的不同来展示不同的条目,那如何来控制不同条目的所占的列数呢?
GridLayoutManager为我们提供了动态改变每个item所占列数的方法:
gridManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return gridManager.getSpanCount();
}
}
getSpanSize方法,返回值就表示当前item占多少列,例如如果我们列数设置的为3列,返回3就表示铺满,也
就是和列表一样了。
如图所示,我们给RecyclerView设置一个列数为6的GridLayoutManager,然后再动态地为不同部位的item分
别设置SpanSize为6(铺满)、3(1/2)、2(1/3)就行了
接下来我就来贴下我所写的代码:
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.rv);
recyclerView.setLayoutManager(new GridLayoutManager(this, 3));
BookDisplayAdapter adapter = new BookDisplayAdapter(this, images, bookNames);
recyclerView.setAdapter(adapter);
下面是Adapter
public class BookDisplayAdapter extends RecyclerView.Adapter {
public static final int TYPE_HEADER = 1;
public static final int TYPE_ITEM = 2;
public static final int TYPE_TITLE = 3;
private int[] images;
private String[] bookNames;
private Context context;
public BookDisplayAdapter(Context context,int[] images, String[] bookNames) {
this.images = images;
this.bookNames = bookNames;
this.context = context;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
switch (viewType){
case TYPE_HEADER:
View headerView = View.inflate(parent.getContext(), R.layout.item_header, null);
return new HeaderHolder(headerView);
case TYPE_ITEM:
View itemView = View.inflate(parent.getContext(), R.layout.item, null);
return new ItemHolder(itemView);
case TYPE_TITLE:
View titleView = View.inflate(parent.getContext(), R.layout.item_title, null);
return new TitleHolder(titleView);
default:
return null;
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof HeaderHolder){
bindHeaderHoder(((HeaderHolder) holder),position);
}else if (holder instanceof ItemHolder){
bindItemHolder(((ItemHolder) holder),position);
}
}
private void bindItemHolder(ItemHolder holder, int position1) {
final int position = position1 - 2;
holder.ivItem.setImageResource(images[position]);
holder.tvItem.setText(bookNames[position]);
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String bookName = bookNames[position];
Toast.makeText(context,bookName,Toast.LENGTH_SHORT).show();
if (mOnItemClickListener!=null){
mOnItemClickListener.onItemClick(bookName);
}
}
});
}
public interface OnItemClickListener{
void onItemClick(String bookName);
}
private OnItemClickListener mOnItemClickListener;
public void setmOnItemClickListener(OnItemClickListener mOnItemClickListener) {
this.mOnItemClickListener = mOnItemClickListener;
}
private void bindHeaderHoder(HeaderHolder holder, int position) {
List<Integer> list = new ArrayList<>();
list.add(R.drawable.banner1);
ConvenientBanner convenientBanner = holder.convenientBanner;
CBViewHolderCreator<LocalImageHolderView> holderCreator = new CBViewHolderCreator<LocalImageHolderView>() {
@Override
public LocalImageHolderView createHolder() {
return new LocalImageHolderView();
}
};
convenientBanner.setPages(holderCreator, list);
}
public class LocalImageHolderView implements Holder<Integer> {
private ImageView imageView;
@Override
public View createView(Context context) {
imageView = new ImageView(context);
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
return imageView;
}
@Override
public void UpdateUI(Context context, final int position, Integer data) {
imageView.setImageResource(data);
}
}
@Override
public int getItemCount() {
return images.length+2;
}
@Override
public int getItemViewType(int position) {
if (position == 0){
return TYPE_HEADER;
}else if (position == 1){
return TYPE_TITLE;
}else {
return TYPE_ITEM;
}
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
if(manager instanceof GridLayoutManager) {
final GridLayoutManager gridManager = ((GridLayoutManager) manager);
gridManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
int type = getItemViewType(position);
switch (type){
case TYPE_HEADER:
case TYPE_TITLE:
return gridManager.getSpanCount();
default:
return 1;
}
}
});
}
}
static class HeaderHolder extends RecyclerView.ViewHolder {
private ConvenientBanner convenientBanner;
public HeaderHolder(View itemView) {
super(itemView);
convenientBanner = (ConvenientBanner) itemView.findViewById(R.id.convenientBanner);
}
}
static class ItemHolder extends RecyclerView.ViewHolder {
private TextView tvItem;
private ImageView ivItem;
public ItemHolder(View itemView) {
super(itemView);
tvItem = (TextView) itemView.findViewById(R.id.tv_item);
ivItem = (ImageView) itemView.findViewById(R.id.iv_item);
}
}
static class TitleHolder extends RecyclerView.ViewHolder {
public TitleHolder(View itemView) {
super(itemView);
}
}
}
最后的效果:
欢迎大家指正!!!