Android Glide Image沒有顯示在第一個屏幕上

Question

我正在使用Android glide加載遠程圖像，但是在這里我遇到了一個奇怪的問題，第一個屏幕上的圖像沒有顯示，但是當我向下滾動並再次向上滾動時，這些圖像變得正常顯示。以下是屏幕截圖： 我也用谷歌搜索了這個問題並找到了一個重復的文件 ，在嘗試了這些步驟后它仍然不起作用，您可能需要檢查代碼，就是這樣：

public class SiteAdapter extends ArrayAdapter<Site> {
private int resourceId;
private List<Site> sites = null;
private Context context;
private SiteHolder siteHolder;
/**
 * @param context the current activity context, we can get it using the super ArrayAdapter constructor
 * @param resource the site_layout.xml file
 * @param objects the collection to store all the sites
 */
public SiteAdapter(Context context, int resource, List<Site> objects) {
    super(context, resource, objects);
    this.context = context;
    this.resourceId = resource;
    this.sites = objects;
}

@Override
public Site getItem(int position) {
    return sites.get(position);
}

@Override
public int getCount() {
    return sites.size();
}

//get the viewpage which inflate by site_layout.xml file
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    Site site = getItem(position);
    View view = convertView;
    siteHolder = new SiteHolder();
    if (view == null) {
        LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = vi.inflate(resourceId, null);
    }
    //this place we need to get the whole widget in site_layout.xml file
    siteHolder.image = (ImageView) view.findViewById(R.id.thumbnail);
    siteHolder.address = (TextView)view.findViewById(R.id.address);
    siteHolder.mallName = (TextView) view.findViewById(R.id.name);
    siteHolder.distance = (TextView) view.findViewById(R.id.distance);
    siteHolder.address.setText(site.getAddress());
    //set name of the view
    siteHolder.mallName.setText(site.getName());
    //set price of the view
    //set distance of the view
    siteHolder.distance.setText("<" + site.getDistance() + "m");
    //set image
    ImageTask task = new ImageTask();
    task.execute("http://xxxx/springmvc/getFirst/" + site.getName());
    return view;
}

//檢測adapater中加載網絡資源是否可行?結論:不可行
public String getImgUrl(String str){
    String data = "";
    try {
        URL u = new URL(str);
        HttpURLConnection conn = (HttpURLConnection) u.openConnection();
        InputStream is = conn.getInputStream();
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        String content = "";
        StringBuffer sb = new StringBuffer();
        while((content = br.readLine()) != null){
            sb.append(content);
        }
        data = sb.toString();
        br.close();
        is.close();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return data;
}
class ImageTask extends AsyncTask<String, Void, String>{

    @Override
    protected String doInBackground(String... str) {
        String data = "";
        data = getImgUrl(str[0]);
        return data;
    }

    @Override
    protected void onPostExecute(String s) {
        Glide.with(context)
            .load(s)
            .fitCenter()
            .into(siteHolder.image);
    }
}

class SiteHolder{
    ImageView image;
    TextView mallName;
    TextView address;
    TextView distance;
    }
}

如果以前有人遇到過這樣的場面，請先謝謝。

Answer 1

參見https://github.com/bumptech/glide/blob/master/README.md#compatibility

圓形圖片 ： CircleImageView / CircularImageView / RoundedImageView已知有問題與TransitionDrawable （ .crossFade()與.thumbnail()或.placeholder()和GIF動畫，使用BitmapTransformation （ .circleCrop()將在V4使用）或.dontAnimate()解決此問題。

簡而言之：舍入視圖總是將傳入的Drawable柵格化為位圖，如果Drawable內有動畫（GIF或crossFade），則將不起作用。

在第一次加載時，在檢索圖像時顯示占位符，然后交叉淡入淡出到圖像； 稍后，當您向上滾動時，圖像會立即從內存緩存中加載，因此沒有動畫。

Answer 2

在https://github.com/bumptech/glide/issues/1508響應時，我發現圖像未加載的潛在根本原因：在getView您覆蓋siteHolder ，所以無論ImageTask完成了什么，它總是更新最后一個綁定行，而不是更新任務開始的原始行。 有關如何在雙發情況下改進Glide相關代碼的更多技巧，請參閱GitHub上的問題。 快速而骯臟的修復：

public class SiteAdapter extends ArrayAdapter<Site> {
    //private SiteHolder siteHolder; // remove this field

public View getView(int position, View convertView, ViewGroup parent) {
    SiteHolder siteHolder = new SiteHolder();
    ...
    ImageTask task = new ImageTask(siteHolder);
    ...
}

static class ImageTask extends AsyncTask<String, Void, String> {
    private SiteHolder siteHolder; // TODO initialize in constructor
    // rest stays the same, but notice the `static` modifier above!
}