打造Android万能适配器Adapter

- 日理万妓 2022-06-18 12:49 251阅读 0赞

# 打造Android万能适配器Adapter #

adapter经常遇到，所以封装了一下，主要是从一下几个方面展开

这篇是受到两位朋友的代码启发写的，感谢一下

# 1.BaseAdapter的抽象方法实现： #

getItem（），getCount（），getItemId()

# 2.getView的实现 #

主要是convertView和ViewHolder

# 3.对于viewHolder的抽象方法和绑定数据的抽象方法 #

# 4.对于数据源的封装 #

主要是set和get以及增删改查的加锁

# 5.代码实现如下： #

import android.content.Context;
    import android.support.annotation.LayoutRes;
    import android.support.annotation.Nullable;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.AdapterView;
    import android.widget.BaseAdapter;
    import android.widget.ListView;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.Comparator;
    import java.util.List;
    
    /** * Created by 刘朋（liupeng） on 2017/4/7. */
    
    public abstract class BaseArrayAdapter<D,Holder> extends BaseAdapter{
      private List<D> mInfos = new ArrayList<>();
      private final Object mLock = new Object();
    
      protected LayoutInflater mInflater;
      protected Context context;
      private boolean mNotifyOnChange = true;
    
      //传递context引用进来
    
      public BaseArrayAdapter(Context context) {
        mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        this.context = context;
      }
    
      //mNotifyOnChange是一个控制的开关
      @Override
      public void notifyDataSetChanged() {
        super.notifyDataSetChanged();
        mNotifyOnChange = true;
      }
      public void setNotifyOnChange(boolean notifyOnChange) {
        mNotifyOnChange = notifyOnChange;
      }
    
      public Context getContext() {
        return context;
      }
    
      public int getCount() {
        return isEmpty() ? 0 : mInfos.size();
      }
    
      public D getItem(int position) {
        return isEmpty() ? null : mInfos.get(position);
      }
    
      public long getItemId(int position) {
        return position;
      }
    
      //覆写getView
      @Override public View getView(int position, View convertView, ViewGroup parent) {
        Holder holder;
        D d = getItem(position);
        if (convertView == null) {
          convertView = mInflater.inflate(getLayoutId(), parent, false);
          holder = onCreateViewHolder(convertView);
          convertView.setTag(holder);
        } else {
          holder = (Holder) convertView.getTag();
        }
        onBindViewHolder(holder, d, position, convertView);
    
        return convertView;
      }
    
      public abstract @LayoutRes int getLayoutId();
    
      /** * 创建Holder */
      public abstract Holder onCreateViewHolder(View convertView);
    
      /** * 绑定数据 */
      public abstract void onBindViewHolder(Holder holder, D d, int position, View convertView);
    
      /** * 局部刷新的方法，如果不指明header个数，这里只考虑listView,其余按0处理 * * @param parent AdapterView * @param position 需要刷新的position,这里的position不包含header */
      public void updateItem(AdapterView parent, int position) {
        int headerCount = 0;
        if (parent instanceof ListView) {
          headerCount = ((ListView) parent).getHeaderViewsCount();
        }
        updateItem(parent, position, headerCount);
      }
      /** * 局部刷新的方法 * * @param parent AdapterView * @param position 需要刷新的position,这里的position不包含header * @param headerCount header个数 */
      public void updateItem(AdapterView parent, int position, int headerCount) {
        int realPosition = position + headerCount;
        int firstVisiblePosition = parent.getFirstVisiblePosition();
        int lastVisiblePosition = parent.getLastVisiblePosition();
        // 判断position是否可见，如果可见调用updateUI方法
        if (realPosition >= firstVisiblePosition && realPosition <= lastVisiblePosition) {
          View view = parent.getChildAt(realPosition - firstVisiblePosition);
          onBindViewHolder((Holder) view.getTag(), getItem(position), position, null);
        }
      }
    
      /** * 这里忽略header * @param parent * @param position * @return */
      public Holder getItemHolder(AdapterView parent, int position){
        return (Holder) parent.getChildAt(position).getTag();
      }
    
      public void setDatas(@Nullable List<D> infos) {
        mInfos = infos;
        notifyDataSetChanged();
      }
    
      public List<D> getDatas() {
        return mInfos;
      }
    
      public boolean isEmpty() {
        return mInfos == null;
      }
    
      public void add(D t) {
        synchronized (mLock) {
          if (isEmpty()) {
            return;
          }
          mInfos.add(t);
        }
        if (mNotifyOnChange) notifyDataSetChanged();
      }
    
      public void addAll(List<D> list) {
        synchronized (mLock) {
          if (isEmpty()) {
            return;
          }
          if (list != null) {
            mInfos.addAll(list);
          }
        }
        if (mNotifyOnChange) notifyDataSetChanged();
      }
    
      public void clear() {
        if (isEmpty()) {
          return;
        }
        synchronized (mLock) {
          mInfos.clear();
        }
        if (mNotifyOnChange) notifyDataSetChanged();
      }
      public void remove(D t){
        synchronized (mLock){
          if(isEmpty()){
            return;
          }
          if(mInfos != null){
            mInfos.remove(t);
          }
        }
        if (mNotifyOnChange) notifyDataSetChanged();
      }
      public void insert(D t, int index){
        synchronized (mLock){
          if(isEmpty()){
            return;
          }
          if(mInfos != null){
            mInfos.add(index,t);
          }
        }
        if (mNotifyOnChange) notifyDataSetChanged();
      }
    
      public void sort(Comparator<? super D> comparator){
        synchronized (mLock){
          if(isEmpty()){
            return;
          }
          if(mInfos != null){
            Collections.sort(mInfos, comparator);
          }
        }
        if (mNotifyOnChange) notifyDataSetChanged();
      }
    }