由于最近使用RecyclerView的一个的开源项目BaseRecyclerViewAdapterHelper,觉得挺好用的,功能很多,也不用写重复的代码了,用起来也很方便,简洁.
简书介绍:
简书地址 https://www.jianshu.com/p/b343fcff51b0
但是有的时候还是会用到 ListView ,由于没有使用开源框架,以前也没记录一些敏捷的工具,所以还是要自己继承google的BaseAdapter, 然后写重复的getView, getItem,之类的,感觉非常不开心..
所以就自己写一下,以后用到就复制粘贴,很爽的!!
封装之后的使用效果:
public class ListAdapter extends BaseListAdapter<TestBean> {
public ListAdapter(Context context, List<TestBean> datas) {
super(R.layout.item_adapter_test, context, datas);
}
@Override
protected void convert(BaseListViewHolder viewHolder, TestBean bean, int position) {
//设置内容和 点击监听
viewHolder.setTest(R.id.item_test_tv, bean.getTitle())
.addOnClickListener(R.id.item_click_btn,position)
.addOnClickListener(R.id.item_test_tv, position);
}
}
对比封装之前的:
public class OldAdapter extends BaseAdapter {
private Context mContext;
private List<Object> mDatas;
public OldAdapter (Context context, List<Object> datas){
mContext = context;
mDatas = datas;
}
@Override
public int getCount() {
return 0;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
if(convertView == null){
convertView = LayoutInflater.from(加载布局);
//省略代码
}
//省略代码
return convertView;
}
static class ViewHolder{
//省略代码
}
}
重复的代码都封装在Base类里面隐藏起来了
瞬间感觉爽了很多,以后再也不用搬砖了...(其实....还是要的)
封装思路:
提供给新人看的.大佬绕路哈!~~(好像也没人看...想多了.)
第一步:
创建一个BaseListAdapter作为基类,数据类型使用泛型,布局redId要实现类传入,然后把公共的代码写在基类
public class BaseListAdapter<B> extends BaseAdapter {
protected Context mContext;
private List<B> mDatas;
private LayoutInflater mInflater;
private int mLayoutResId;
public BaseListAdapter(@LayoutRes int layoutResId, Context context, List<B> datas){
mContext = context;
mDatas = datas;
mLayoutResId = layoutResId;
mInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
if(mDatas != null){
return mDatas.size();
}
return 0;
}
@Override
public B getItem(int position) {
if(mDatas != null){
return mDatas.get(position);
}
return null;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
return null;
}
}
第二步:
处理好 getView() 方法
按照以前的写法,都会为Adapter创建一个 ViewHolder 来记录
itemView 里面的子View,所以这里就封装一个BaseListViewHolder ,通过构造,把整个ItemView保存到ViewHolder 里面
public class BaseListViewHolder {
private View convertView;
private BaseListAdapter mAdapter;
//缓存view, key是id
private final SparseArray<View> mViews;
public BaseListViewHolder(View itemView){
mViews = new SparseArray<>();
convertView = itemView;
}
public BaseListViewHolder setAdapter(BaseListAdapter adapter) {
mAdapter = adapter;
return this;
}
}
这个时候 getView() 就可以这样写了
@Override
public View getView(int position, View convertView, ViewGroup parent) {
BaseListViewHolder viewHolder;
if(convertView == null){
convertView = mInflater.inflate(mLayoutResId,parent,false);
viewHolder = bindViewHolder(convertView);
viewHolder.setAdapter(this);
convertView.setTag(viewHolder);
}else {
viewHolder = (BaseListViewHolder) convertView.getTag();
}
convert(viewHolder,getItem(position),position);
return convertView;
}
//抽象方法,子类实现
protected abstract void convert(BaseListViewHolder viewHolder, B bean ,int position);
这里差不多就完成整个Adapter的封装了,还有一些其他事情需要在 BaseListViewHolder 里面处理,比如我们需要 数据绑定,设置子View的背景,字体颜色,点击事件等等...
完整的BaseListAdapter
public abstract class BaseListAdapter<B> extends BaseAdapter {
protected Context mContext;
private List<B> mDatas;
private LayoutInflater mInflater;
private int mLayoutResId;
public BaseListAdapter(@LayoutRes int layoutResId, Context context,List<B> datas){
mContext = context;
mDatas = datas;
mLayoutResId = layoutResId;
mInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
if(mDatas != null){
return mDatas.size();
}
return 0;
}
@Override
public B getItem(int position) {
if(mDatas != null){
return mDatas.get(position);
}
return null;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
BaseListViewHolder viewHolder;
if(convertView == null){
convertView = mInflater.inflate(mLayoutResId,parent,false);
viewHolder = bindViewHolder(convertView);
convertView.setTag(viewHolder);
viewHolder.setAdapter(this);
}else {
viewHolder = (BaseListViewHolder) convertView.getTag();
}
convert(viewHolder,getItem(position),position);
return convertView;
}
protected abstract void convert(BaseListViewHolder viewHolder, B bean ,int position);
private BaseListViewHolder bindViewHolder(View convertView){
return new BaseListViewHolder(convertView);
}
/**
* 监听子View的点击事件
*/
public void setOnItemChildClickListener(OnItemChildClickListener listener) {
mOnItemChildClickListener = listener;
}
public OnItemChildClickListener getOnItemChildClickListener() {
return mOnItemChildClickListener;
}
private OnItemChildClickListener mOnItemChildClickListener;
public interface OnItemChildClickListener{
void onItemChildClick(BaseListAdapter adapter, View view, int position);
}
}
完整的BaseListViewHolder
public class BaseListViewHolder {
private View convertView;
private BaseListAdapter mAdapter;
//缓存view, key是id
private final SparseArray<View> mViews;
public BaseListViewHolder(View itemView){
mViews = new SparseArray<>();
convertView = itemView;
}
public View getConvertView() {
return convertView;
}
public <T extends View> T getView(@IdRes int viewId) {
View view = mViews.get(viewId);
if (view == null) {
view = convertView.findViewById(viewId);
mViews.put(viewId, view);
}
return (T) view;
}
public BaseListViewHolder setTest(@IdRes int viewId ,CharSequence value) {
TextView view = getView(viewId);
view.setText(value);
return this;
}
public BaseListViewHolder setImageResource(@IdRes int viewId, @DrawableRes int imageResId) {
ImageView view = getView(viewId);
view.setImageResource(imageResId);
return this;
}
public BaseListViewHolder setBackgroundColor(@IdRes int viewId, @ColorInt int color) {
View view = getView(viewId);
view.setBackgroundColor(color);
return this;
}
public BaseListViewHolder setTextColor(@IdRes int viewId, @ColorInt int textColor) {
TextView view = getView(viewId);
view.setTextColor(textColor);
return this;
}
public BaseListViewHolder setVisible(@IdRes int viewId, boolean visible) {
View view = getView(viewId);
view.setVisibility(visible ? View.VISIBLE : View.GONE);
return this;
}
public BaseListViewHolder addOnClickListener(@IdRes int viewId, final int position) {
final View view = getView(viewId);
if (view != null) {
if (!view.isClickable()) {
view.setClickable(true);
}
view.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mAdapter.getOnItemChildClickListener() != null) {
mAdapter.getOnItemChildClickListener().onItemChildClick(mAdapter, v, position);
}
}
});
}
return this;
}
public BaseListViewHolder setAdapter(BaseListAdapter adapter) {
mAdapter = adapter;
return this;
}
}
这里只实现一些基础的功能,如需添加,可以自己实现
