Question

在for循环中，它仅显示最后的数据。在数据库中，有多少行是通过获取最后一项来显示的所有行都采用最后的图像和文本现在我想在listview中显示数据库中的所有图像和文本。请帮助我

enter code here
  public class ImageAdapter extends BaseAdapter {
private static final Context Context = null;
String qrimage;
Bitmap bmp, resizedbitmap;
Activity activity = null;
private static LayoutInflater inflater;

private ImageView[] mImages;
String[] itemimage;
TextView[] tv;
String itemname;
HashMap<String, String> map = new HashMap<String, String>();

public ImageAdapter(Context context, JSONArray imageArrayJson) {
    //inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  //  imageLoader=new ImageLoader(activity);
    inflater=LayoutInflater.from(context);
    this.mImages = new ImageView[imageArrayJson.length()];

    try {

        for (int i = 0; i < imageArrayJson.length(); i++) {
            JSONObject image = imageArrayJson.getJSONObject(i);
            qrimage = image.getString("itemimage");
            itemname = image.getString("itemname");
            map.put("itemname", image.getString("itemname"));


            byte[] qrimageBytes = Base64.decode(qrimage.getBytes());

            bmp = BitmapFactory.decodeByteArray(qrimageBytes, 0,
                    qrimageBytes.length);
            int width = 100;
            int height = 100;
            resizedbitmap = Bitmap.createScaledBitmap(bmp, width, height,
                    true);

            mImages[i] = new ImageView(context);
            mImages[i].setImageBitmap(resizedbitmap);

            mImages[i].setScaleType(ImageView.ScaleType.FIT_START);


            // tv[i].setText(itemname);
        }
        System.out.println(map);

    } catch (Exception e) {
        // TODO: handle exception
    }
}

public int getCount() {
    return mImages.length;
}

public Object getItem(int position) {
    return position;
}

public long getItemId(int position) {
    return position;
}



public View getView(int position, View convertView, ViewGroup parent) {


    View vi=convertView;

            vi = inflater.inflate(R.layout.listview, null);


       TextView text=(TextView)vi.findViewById(R.id.text);
        ImageView image=(ImageView)vi.findViewById(R.id.image);
        image.setImageBitmap(bmp);
        text.setText(map.get("itemname"));

        return vi;


 }


}

Answer 1

这一行将把所有内容存储在地图中的一个位置：

map.put("itemname", image.getString("itemname"));

但也许你的意思是：

map.put(itemname, image.getString("itemname"));

您还有一个bmp字段，每次循环都会重置。由于某种原因，您的getView方法有一个position参数，因此它可以索引到一个数组中，并在列表中找到该点的相应信息。相反，您的getView正在为整个适配器实例检索一个bmp和一个itemname - 而不是position所应的索引。

我可能不应该只是给你代码，但在这里。

public class ImageAdapter extends BaseAdapter {
  String qrimage;
  Bitmap bmp, resizedbitmap;
  Bitmap[] bmps;
  Activity activity = null;
  private LayoutInflater inflater;

  private ImageView[] mImages;
  String[] itemimage;
  TextView[] tv;
  String itemname;
  String[] itemnames;
  HashMap<String, String> map = new HashMap<String, String>();

  public ImageAdapter(Context context, JSONArray imageArrayJson) {
    //inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    //  imageLoader=new ImageLoader(activity);
    inflater=LayoutInflater.from(context);
    this.mImages = new ImageView[imageArrayJson.length()];
    this.bmps = new Bitmap[imageArrayJson.length()];
    this.itemnames = new String[imageArrayJson.length()];

    try {

      for (int i = 0; i < imageArrayJson.length(); i++) {
        JSONObject image = imageArrayJson.getJSONObject(i);
        qrimage = image.getString("itemimage");
        itemname = image.getString("itemname");
        itemnames[i] = itemname;


        byte[] qrimageBytes = Base64.decode(qrimage.getBytes());

        bmp = BitmapFactory.decodeByteArray(qrimageBytes, 0,
                                            qrimageBytes.length);
        int width = 100;
        int height = 100;
        resizedbitmap = Bitmap.createScaledBitmap(bmp, width, height,
                                                  true);
        bmps[i] = bmp;

        mImages[i] = new ImageView(context);
        mImages[i].setImageBitmap(resizedbitmap);

        mImages[i].setScaleType(ImageView.ScaleType.FIT_START);


        // tv[i].setText(itemname);
      }
      System.out.println(map);

    } catch (Exception e) {
      // TODO: handle exception
    }
  }

  public int getCount() {
    return mImages.length;
  }

  public Object getItem(int position) {
    return position;
  }

  public long getItemId(int position) {
    return position;
  }



  public View getView(int position, View convertView, ViewGroup parent) {


    View vi=convertView;

    vi = inflater.inflate(R.layout.listview, null);


    TextView text=(TextView)vi.findViewById(R.id.text);
    ImageView image=(ImageView)vi.findViewById(R.id.image);
    image.setImageBitmap(bmps[position]);
    text.setText(itemnames[position]);

    return vi;


  }


}

在android中使用基本适配器仅显示列表视图中的最后一个图像和文本

1 个答案: