将 listview 适配器更改为回收器视图适配器

Posted 2023-05-07

【中文标题】将 listview 适配器更改为回收器视图适配器

【英文标题】：Change listview adapter to recycler view adapter

【发布时间】：2016-04-05 15:49:16

【问题描述】：

当我将图像从 SD 卡加载到 ListView 时，它开始滞后。我不能流畅地滚动。所以，我决定使用回收站视图，也许还有毕加索。我面临的唯一问题是，ListView 适配器无法与 RecyclerView 一起使用。

如何重写以下代码/适配器以使用 RecyclerView？

万事如意，新年快乐！

public class Saveditems extends BaseActivity 

ArrayList<String> f = new ArrayList<>();// list of file paths
File[] listFile;


@Override
public void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);

    setContentView(R.layout.saveditems);

    activateToolbarWithHomeEnabled().setNavigationOnClickListener(new View.OnClickListener() 

        @Override
        public void onClick(View v) 

            finish();

        

    );

    getFromSdcard();

    RecyclerView imagelist = (RecyclerView) findViewById(R.id.PhoneImageGrid);

    ImageAdapter imageAdapter = new ImageAdapter();

    imagelist.setAdapter(imageAdapter); //error
    //image adapter cannot be applied to recycler view



public void getFromSdcard() 

    File file = new File(Environment.getExternalStorageDirectory() + "/FlickrBrowser");

    if (file.isDirectory()) 

        listFile = file.listFiles();

        for (File aListFile : listFile) 

            f.add(aListFile.getAbsolutePath());

        
    


public class ImageAdapter extends BaseAdapter 
    private LayoutInflater mInflater;

    public ImageAdapter() 
        mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    

    public int getCount() 
        return f.size();
    

    public Object getItem(int position) 
        return position;
    

    public long getItemId(int position) 
        return position;
    

    @SuppressLint("InflateParams")
    public View getView(int position, View convertView, ViewGroup parent) 

        ViewHolder holder;

        if (convertView == null) 

            holder = new ViewHolder();
            convertView = mInflater.inflate(
                    R.layout.galleryitem, null);
            holder.imageview = (ImageView) convertView.findViewById(R.id.thumbImage);

            convertView.setTag(holder);

         else 

            holder = (ViewHolder) convertView.getTag();
        

        Bitmap myBitmap = BitmapFactory.decodeFile(f.get(position));
        holder.imageview.setImageBitmap(myBitmap);
        return convertView;

    



class ViewHolder 

    ImageView imageview;

【参考方案1】：

public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ImageHolder> 

    List<String> f;

    public ImageAdapter(List<String> list) 

    f=list;

     

    @Override
    public ImageHolder onCreateViewHolder(ViewGroup parent, int viewType) 
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.yourlayout, parent, false);
        return new ImageHolder(v);
    

    @Override
    public void onBindViewHolder(final ImageHolder holder, final int position) 

        Bitmap myBitmap = BitmapFactory.decodeFile(f.get(position));
        holder.imageview.setImageBitmap(myBitmap);

    

    public static class ImageHolder extends RecyclerView.ViewHolder 


    ImageView imageview;

    public ImageHolder(View itemView)
        super(itemView);
        imageview=(ImageView)itemView.findViewById(R.id.yourimageid)
    

  

【讨论】：

不幸的是，我无法让它工作。 ImageAdapter 中未定义数组列表“f”。

将其传递给 imageadapter 构造函数

我很感激！谢谢，我试试看。