生活本來就不容易啊，正是我們的不努力才會讓生活變得更加無賴铆隘。
整個月沒有寫過博客卓舵，這幾天趁著看項目代碼有使用到ListView添加headView決定自己更新一下，使用RecyclerView來代替膀钠，記得之前就寫過一篇關(guān)于ReCyclerView的基本使用(一)掏湾，這次寫個續(xù)集吧。但是我們在setHeadView()的時候并沒有發(fā)現(xiàn)有這個方法肿嘲，至于為什么呢我也不知道融击，但是各路大神已經(jīng)優(yōu)雅的為其添加HeadView和FootView了例如鴻洋大神,還有Loader的，還有很多很多雳窟，所以基本上不用寫了尊浪，這篇筆記到此結(jié)束。嗯封救！
但是這筆記的意義不在此拇涤，只是想記錄一下自己的參考過程，不誉结，是思考過程鹅士。首先看看整個demo的預(yù)覽圖
阿拉蕾
基本思路
利用RecyclerView.Adapter中的getItemType()方法判斷一下這是否為headView,footView,在onCreateViewHolder(ViewGroup parent, int viewType)方法中判斷一下要給Viewholder的itemView是什么類型。就這樣惩坑。下面直接看代碼吧
基本實現(xiàn)
BaseRecyclerAdapter
/**
* Created by AmatorLee on 2016/10/29.
* 基類Adaper
*/
public abstract class BaseRecyclerAdapter<T> extends RecyclerView.Adapter<BaseRecyclerViewHolder>{
private static final int ITEM_HEAD = 1000;
private static final int ITEM_FOOT = 2000;
private static final int ITEM_NOMAL = 3000;
private View mHeadView;
private View mFootView;
private List<T> mDatas;
private LayoutInflater mInflater;
/**
* 點擊回調(diào)
*/
private OnItemClickListener mListener;
public void setListener(OnItemClickListener listener) {
mListener = listener;
}
/**
* 構(gòu)造方法
* @param context
* @param mDatas
*/
public BaseRecyclerAdapter(Context context, List<T> mDatas) {
mInflater = LayoutInflater.from(context);
this.mDatas = mDatas;
}
/**
* headView
* @param headView
*/
public void addHeadView(View headView){
this.mHeadView = headView;
notifyItemInserted(0);
}
public View getHeadView(){
if (mHeadView != null){
return mHeadView;
}
return null;
}
/**
* FootView
* @param footView
*/
public void addFootView(View footView){
this.mFootView = footView;
notifyItemInserted(getItemCount() - 1);
}
public View getFootView(){
if (mFootView != null){
return mFootView;
}
return null;
}
@Override
public BaseRecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (mHeadView != null && viewType == ITEM_HEAD){
//如果為headView則itemView為headView
return new BaseRecyclerViewHolder(mHeadView);
}else if (mFootView != null && viewType == ITEM_FOOT){
//如果為footView則itemView為footView
return new BaseRecyclerViewHolder(mFootView);
}
//否則自己解析
return new BaseRecyclerViewHolder(mInflater.inflate(getLayoutID(),parent,false));
}
/*此方法為解析自己的view提供一個layoutId*/
public abstract int getLayoutID();
@Override
public void onBindViewHolder(BaseRecyclerViewHolder holder, final int position) {
/*判斷是否有headView掉盅，如果0被占用則position-1*/
final int pos = getLayoutPos(holder);
if (getItemViewType(position) == ITEM_HEAD)return;/*交予自己處理headView*/
if (getItemViewType(position) == ITEM_FOOT)return;/*處理footView*/
/*點擊監(jiān)聽*/
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mListener != null){
mListener.onItemClick(v,pos);
}
}
});
/*自己處理數(shù)據(jù)的方法*/
onBindData(holder,pos);
}
/*判斷是否有headView也拜，如果0被占用則position-1*/
private int getLayoutPos(BaseRecyclerViewHolder holder){
return mHeadView == null?holder.getLayoutPosition():holder.getLayoutPosition() - 1;
}
/*自己處理數(shù)據(jù)的方法*/
public abstract void onBindData(BaseRecyclerViewHolder holder, int position);
@Override
public int getItemCount() {
if (mHeadView == null && mFootView != null){
//如果footView則count+1
return mDatas.size() + 1;
}else if (mHeadView != null && mFootView == null){
//如果有headView則+1
return mDatas.size()+ 1;
}else if(mFootView != null && mHeadView != null){
//假如都有則+2
return mDatas.size() + 2;
}
/*否則不處理*/
return mDatas.size();
}
/***
* 此方法判斷itemType的類型
* @param position
* @return
*/
@Override
public int getItemViewType(int position) {
if (mHeadView == null && mFootView == null)return ITEM_NOMAL;
if (position == 0 && mHeadView != null) return ITEM_HEAD;
if (position == getItemCount() -1) return ITEM_FOOT;
return ITEM_NOMAL;
}
/**
*回調(diào)監(jiān)聽
*/
public interface OnItemClickListener{
void onItemClick(View v, int pos);
}
}```
**BaseViewHolder**
/**
- Created by AmatorLee on 2016/10/29.
- 基類Viewholder
*/
public class BaseRecyclerViewHolder extends RecyclerView.ViewHolder{
private SparseArray<View> mViews;/*傳說中裝在view性能好的容器，key為int型趾痘，value為View*/
public View itemView;
/**
* 構(gòu)造方法
* @param itemView
*/
public BaseRecyclerViewHolder(View itemView) {
super(itemView);
mViews = new SparseArray<>();
this.itemView = itemView;
}
/**
* 利用SpaseArray和泛型省略多次findViewbyid()
* @param viewId id
* @param <T> 類型
* @return
*/
public <T extends View>T getView(int viewId){
View view = mViews.get(viewId);
if (view == null){
view = itemView.findViewById(viewId);
mViews.put(viewId,view);
}
return (T) view;
}
/**
* 給外部調(diào)用的設(shè)置文本的方法
* @param viewId
* @param msg
*/
public void setText(int viewId,String msg){
TextView textView = getView(viewId);
textView.setText(msg);
}
/**
* 給外部調(diào)用的設(shè)置圖片資源的方法
* @param viewID
* @param resID
*/
public void setImgRes(int viewID,int resID){
ImageView imageView = getView(viewID);
imageView.setImageResource(resID);
}
}```
- 這里定義了一個
BaseRecyclerAdapter And BaseViewHolder用以處理是否添加headView慢哈，代碼注釋比較清楚。
基本使用
使用起來也是十分簡單扼脐，我們新建一個自己的TestAdapter擴(kuò)展自BaseRecyclerAdapter岸军，需要實現(xiàn)其兩個抽象方法：
@Override
public int getLayoutID() {
return R.layout.recycler_test;/*提供需要解析的layoutID*/
}
@Override
public void onBindData(BaseRecyclerViewHolder holder, int position) {
//處理數(shù)據(jù)
holder.setText(R.id.recycler_textView,mDatas.get(position));
}```
**TestAdapter**
/**
Created by AmatorLee on 2016/10/29.
-
目的Adapter，處理自己的相關(guān)邏輯
*/
public class TestAdapter extends BaseRecyclerAdapter<String> {private List<String> mDatas;
private LayoutInflater mInflater;public TestAdapter(Context context, List<String> mDatas) {
super(context, mDatas);
mInflater = LayoutInflater.from(context);
this.mDatas = mDatas;
}@Override
public int getLayoutID() {
return R.layout.recycler_test;
}@Override
public void onBindData(BaseRecyclerViewHolder holder, int position) {
holder.setText(R.id.recycler_textView,mDatas.get(position));
}
}```
Activity
public class HFActivity extends AppCompatActivity {
private List<String> mDatas = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hf);
for (int i = 0; i < 30; i++) {
mDatas.add("這是第" + i + "item");
}
RecyclerView recycler_hf = (RecyclerView) findViewById(R.id.recycler_hf);
recycler_hf.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false));
TestAdapter adapter = new TestAdapter(this, mDatas);
recycler_hf.addItemDecoration(new ItemDecoration(this,LinearLayoutManager.VERTICAL));
View view = getLayoutInflater().inflate(R.layout.layout_headview, null);
adapter.addFootView(view);
adapter.addHeadView(view);
recycler_hf.setAdapter(adapter);
adapter.setListener(new BaseRecyclerAdapter.OnItemClickListener() {
@Override
public void onItemClick(View v, int pos) {
Toast.makeText(HFActivity.this,pos + "onClick",Toast.LENGTH_SHORT).show();
}
});
}
}```
**效果演示**
最近覺得要多使用github了瓦侮，所以把自己寫的一些demo放在github上面吧
[github地址](https://github.com/AmatorLee/RDemo/tree/master)
---
**總結(jié)**
RecyclerView已經(jīng)在逐步取代listView了艰赞，但是相對來說listview使用起來更加方便，雖然目前很多大神已經(jīng)將RecyclerView封裝得完美肚吏，但是我不是啊方妖，雖然可以用，但是我更加希望在使用之前可以先學(xué)習(xí)一遍罚攀。
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