我想在列表视图中加载数据之后从服务器加载图像。我知道这个问题存在很多主题，但我还没有找到解决方案......
所以这是我的代码：
//asyncTackClass for loadingpictures
public class LoadImagesThread extends AsyncTask<Bundle, Void, Bitmap> {
private ImageView view;
private Bitmap bm;
private Context context;
private final WeakReference<ImageView> imageViewReference;
private final String BUNDLE_URL = "url";
private final String BUNDLE_NAME = "name";
private final String BUNDLE_BM = "bm";
public LoadImagesThread(Context context, ImageView view) {
this.context=context;
imageViewReference = new WeakReference<ImageView>(view);
}
@Override
protected Bitmap doInBackground(Bundle... b) {
Bitmap bm =null;
if (StorageHelper.getBitmap(b[0].getString(BUNDLE_NAME)) != null) { // Check the sdcard
bm = StorageHelper.getBitmap(b[0].getString(BUNDLE_NAME));
Log.w("LoadImagesThread", "Get image from sdcard : "+b[0].getString(BUNDLE_NAME));
} else { // Check the server
bm = ServiceHelper.getBitmapFromURL(b[0].getString(BUNDLE_URL));
StorageHelper.saveBitmap(bm, b[0].getString(BUNDLE_NAME)); // Save image on sdcard
Log.w("LoadImagesThread", "Get image from server : "+b[0].getString(BUNDLE_NAME));
}
return bm;
}
@Override
protected void onPostExecute(final Bitmap bm) {
super.onPostExecute(bm);
if (bm != null){ //if bitmap exists...
view = imageViewReference.get();
// Fade out
Animation fadeOutAnimation = AnimationUtils.loadAnimation(context, R.anim.fadeoutimage);
fadeOutAnimation.setAnimationListener(new AnimationListener() {
public void onAnimationStart(Animation animation) {
}
public void onAnimationRepeat(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
// Fade in
view.setImageBitmap(bm);
Animation fadeInAnimation = AnimationUtils.loadAnimation(context, R.anim.fadeinimage);
view.startAnimation(fadeInAnimation);
}
});
// Launch the fadeout
view.startAnimation(fadeOutAnimation);
}else{ //if not picture, display the default ressource
view.setImageResource(R.drawable.productcarre);
}
}
}
该代码用于在 ImageView 中显示 Bitmap
这是适配器：
public class ListViewShoplistStoresAdapter extends BaseAdapter {
private ArrayList<Shop> shopList;
private Activity activity;
private HashMap<Integer, ImageView> views;
private final String BUNDLE_URL = "url";
private final String BUNDLE_NAME = "name";
private final String BUNDLE_POS = "pos";
private final String BUNDLE_ID = "id";
public ListViewShoplistStoresAdapter(Activity activity, ArrayList<Shop> shopList) {
super();
this.activity = activity;
this.shopList = shopList;
this.views = new HashMap<Integer, ImageView>();
}
public int getCount() {
return shopList.size();
}
public Object getItem(int position) {
return shopList.get(position);
}
public long getItemId(int position) {
return shopList.get(position).getId();
}
private class ViewHolder {
public TextView store;
public TextView name;
public ImageView ImageStore;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder view;
LayoutInflater inflator = activity.getLayoutInflater();
if(convertView == null) {
view = new ViewHolder();
convertView = inflator.inflate(R.layout.listviewshops, null);
view.store = (TextView) convertView.findViewById(R.id.store);
view.name = (TextView) convertView.findViewById(R.id.name);
view.ImageStore = (ImageView) convertView.findViewById(R.id.imgstore);
convertView.setTag(view);
}else {
view = (ViewHolder) convertView.getTag();
}
Typeface regular=Typeface.createFromAsset(activity.getAssets(), "fonts/RobotoRegular.ttf");
view.store.setTypeface(regular);
Typeface light=Typeface.createFromAsset(activity.getAssets(), "fonts/RobotoLight.ttf");
view.store.setTypeface(light);
Brand brand = StorageHelper.getBrand(activity, shopList.get(position).getBrandId());
if (brand == null) {
Log.e("SetShopInAdapter","Brand null");
Toast.makeText(activity, "Impossible d'afficher la liste de magasins", Toast.LENGTH_LONG).show();
} else {
view.store.setText(brand.getName());
view.name.setText(shopList.get(position).getName());
view.ImageStore.setImageResource(R.drawable.productcarre);
}
Bundle b = new Bundle();
//url of the pict
b.putString(BUNDLE_URL, ServiceHelper.getImageUrl("brand", brand.getName()));
// name of image
b.putString(BUNDLE_NAME, ServiceHelper.getCleanImageName(brand.getName()));
//position in the listView
b.putInt(BUNDLE_POS, position);
//id of the current object
b.putInt(BUNDLE_ID, brand.getId());
//put info in the map in order to display in the onPostExecute
if(views.get(position)==null){
views.put(position, view.ImageStore);
// launch thread
new LoadImagesThread(activity.getApplicationContext(), view.ImageStore).execute(b);
}
return convertView;
}
}
因此，当我使用 GridView 时，没有任何问题，但是当我使用 ListView 时，图像仅在第一项中更改！
示例：我想显示“汽车”、“房子”和“苹果”项目的产品图像。代码将启动线程，所有图像（汽车然后是房子，最后是苹果）将显示在第一个项目（汽车项目）中......而房子和苹果虽然没有图像！
你知道我应该怎么做吗？
谢谢