java - BitmapFactory 解码流在 ListView 中不起作用

Question

自定义列表.java

public class CustomList extends ArrayAdapter<String> {
    private final Activity context;
    private final ArrayList<String> web;
    private final ArrayList<InputStream> imglist;

    public CustomList(Activity context, ArrayList<String> alist,
            ArrayList<InputStream> bitmapArray) {
        super(context, R.layout.listview_custom, alist);
        this.context = context;
        this.web = alist;
        this.imglist = bitmapArray;
    }

    @Override
    public View getView(int position, View view, ViewGroup parent) {
        LayoutInflater inflater = context.getLayoutInflater();
        View rowView = inflater.inflate(R.layout.listview_custom, null);

        TextView txtTitle = (TextView) rowView
                .findViewById(R.id.drawer_item_text);

        ImageView imageView = (ImageView) rowView
                .findViewById(R.id.drawer_item_icon);

        txtTitle.setText(web.get(position));

        if (imglist.get(position) != null) {
            imageView.setImageBitmap(BitmapFactory.decodeStream(imglist
                    .get(position)));
        } else {
            imageView.setImageResource(R.drawable.ic_launcher);
        }
        System.out.println("Image Input sream " + imglist.get(position));

        return rowView;
    }
}

自定义适配器

bitmapArray.add(openPhoto(contact_id_long));

CustomList adapter = new CustomList(MainActivity.this, Alist,
                        bitmapArray); 

                list.setAdapter(adapter);
public InputStream openPhoto(long contactId) {
    Uri contactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI,
            contactId);
    Uri photoUri = Uri.withAppendedPath(contactUri,
            Contacts.Photo.CONTENT_DIRECTORY);
    Cursor cursor = getContentResolver().query(photoUri,
            new String[] { Contacts.Photo.PHOTO }, null, null, null);
    if (cursor == null) {
        return null;
    }
    try {
        if (cursor.moveToFirst()) {
            byte[] data = cursor.getBlob(0);
            if (data != null) {
                return new ByteArrayInputStream(data);
            }
        }
    } finally {
        cursor.close();
    }
    return null;
}

自定义数组适配器，我可以看到文本，但看不到图像，但是当我 checkin 日志时，InputStream 工作正常，如果我在 ListView 之外使用 BitmapFactory.decodeStream 我可以看到图像。提前致谢。

Answer 1

您存储一个InputStream对象列表并从中解码位图。但是输入流一旦使用就会返回null。存储路径而不是输入流。 还有诸如标记然后重置输入流之类的事情(InputStream 类的 mark() 和 reset() 方法)。但我不建议使用它们。我记得有一个关于此方法使用和位图解码的错误。