我尝试使用动态图像制作listview，使用asynctask下载图像并设置为listview。我的问题是当向下滚动图像时随机改变..
class ps1 extends ArrayAdapter<String> {
Context context;
String[] images1;
List mList;
String[] namearray;
String[] rating;
static class ViewHolder {
ImageView localImageView1;
ImageView localImageView2;
ImageView localImageView3;
}
ps1(Context paramContext, String[] paramArrayOfString1, String[] paramArrayOfString2, String[] paramArrayOfString3) {
super(paramContext, R.layout.list2, R.id.imageView1, paramArrayOfString1);
this.context = paramContext;
this.images1 = paramArrayOfString3;
this.namearray = paramArrayOfString1;
this.rating = paramArrayOfString2;
}
public View getView(int paramInt, View paramView, ViewGroup paramViewGroup) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(context.LAYOUT_INFLATER_SERVICE);
ViewHolder viewHolder = new ViewHolder();
if (paramView == null) {
paramView = inflater.inflate(R.layout.list2, paramViewGroup, false);
}
viewHolder.localImageView1 = (ImageView) paramView
.findViewById(R.id.imageView1);
viewHolder.localImageView2 = (ImageView) paramView
.findViewById(R.id.imageView2);
viewHolder.localImageView3 = (ImageView) paramView
.findViewById(R.id.imageView3);
viewHolder.localImageView1.setScaleType(ImageView.ScaleType.FIT_XY);
viewHolder.localImageView2.setScaleType(ImageView.ScaleType.FIT_XY);
viewHolder.localImageView3.setScaleType(ImageView.ScaleType.FIT_XY);
viewHolder.localImageView1.setTag(this.namearray[paramInt]);
new LoadImage().execute(viewHolder.localImageView1);
viewHolder.localImageView2.setTag(this.rating[paramInt]);
new LoadImage().execute(viewHolder.localImageView2);
viewHolder.localImageView3.setTag(this.images1[paramInt]);
new LoadImage().execute(viewHolder.localImageView3);
return paramView;
}
}
class LoadImage extends AsyncTask<Object, Void, Bitmap> {
private ImageView imv;
private Bitmap download_Image(String paramString) {
Bitmap localBitmap = null;
try {
Object localObject = null;
localBitmap = BitmapFactory
.decodeStream(((HttpURLConnection) new URL(paramString)
.openConnection()).getInputStream());
localObject = localBitmap;
if (localObject != null) {
return localBitmap;
}
} catch (Exception e) {
}
return localBitmap;
}
protected Bitmap doInBackground(Object... paramVarArgs) {
this.imv = ((ImageView) paramVarArgs[0]);
Log.d("fsdf", (String) this.imv.getTag());
return download_Image((String) this.imv.getTag());
}
protected void onPostExecute(Bitmap paramBitmap) {
this.imv.setImageBitmap(paramBitmap);
}
}
答案 0 :(得分：0)
我也经历过同样的事情。我也在寻找合适的解决方案。据我所知，我发现ListView在向下滚动时清除了上一个视图，并在向后滚动时重新加载它。因此，在向上和向下滚动时，您的图像可能会重新循环并且不对齐。 （我也在等待正确的解决方案）。
但是我使用SmartImageView来解决它，这是一个直接下载图像并将其设置为ImageView的库。它会将图像保存在缓存中，因此您可以获得正确的图像。
相比之下，这也更快。
答案 1 :(得分：-1)
尝试使用我在应用程序中使用过的代码段，它在我的应用程序中正常运行，我相信它会在你的最后工作。 在我的情况下，我正在从服务器检索图像和一些数据，并保持列表上的所有图像滚动正常。
class OfferCustomListAdapter extends ArrayAdapter<String>
{
private Context context;
Boolean OddNumber;
ArrayList<String> getDealID = new ArrayList<String>();
ArrayList<String> getInAdpterUNamedlist = new ArrayList<String>();
ArrayList<String> getShopNData = new ArrayList<String>();
ArrayList<String> getUserFav = new ArrayList<String>();
ArrayList<String> getTotalAmt = new ArrayList<String>();
ArrayList<String> getDealImage = new ArrayList<String>();
ArrayList<Boolean> getBoolnState = new ArrayList<Boolean>();
//String Oflist[] ;
int favCount=0;
public OfferCustomListAdapter(Context context,ArrayList<String> dealIdlist, ArrayList<Boolean> AddBoolnList, ArrayList<String> dealNamelist,ArrayList<String> ShopNList,ArrayList<String> UserFave,ArrayList<String> TotalAmt,ArrayList<String> ImageList) {
super(context, android.R.layout.simple_list_item_1,dealNamelist);
this.context=context;
//Oflist = getFolwerUNamelis;
getDealID = dealIdlist;
getInAdpterUNamedlist = dealNamelist;
getShopNData = ShopNList;
getUserFav = UserFave;
getTotalAmt = TotalAmt;
getDealImage = ImageList;
getBoolnState = AddBoolnList;
}
@Override
public View getView(final int pos, View view, ViewGroup parent) {
final ViewHolder holder;
if (view == null) {
LayoutInflater inflater = LayoutInflater.from(this.context);
//view = inflater.inflate(R.layout.offer_custom_list, parent,false);
view = inflater.inflate(R.layout.reservatin_row, parent,false);
holder = new ViewHolder();
//holder.FollowrName = (TextView) view.findViewById(R.id.OfferNameTxt);
holder.DealName = (TextView) view.findViewById(R.id.tv_name);
holder.ShopName = (TextView) view.findViewById(R.id.tv_address);
holder.FavBtn = (ImageView) view.findViewById(R.id.Ofr_FavBtn);
holder.listLayout = (LinearLayout) view.findViewById(R.id.OfferListLayout);
holder.profile_image = (ImageView)view.findViewById(R.id.profile_img);
holder.OfferAmtBtn =(Button)view.findViewById(R.id.TotalOfrBtn);
//holder.FavBtn = (ImageView) view.findViewById(R.id.offerFavBtn);
holder.FavBtn.setTag(pos);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
if ( pos % 2 == 0 ){
System.out.println("You entered an even number. "+pos % 2);
holder.listLayout.setBackgroundResource(R.drawable.offer_list_bg);
}else{
System.out.println("You entered an odd number.");
holder.listLayout.setBackgroundResource(R.drawable.special_offer_bg);
}
/*if(getUserFav.get(pos).equals("0")){
//BolArraylist.add(false);
holder.FavBtn.setBackgroundResource(R.drawable.fav_btn);
}else{
//BolArraylist.add(true);
holder.FavBtn.setBackgroundResource(R.drawable.fav_active_btn);
}*/
holder.DealName.setText(getInAdpterUNamedlist.get(pos));
holder.ShopName.setText(getShopNData.get(pos));
holder.OfferAmtBtn.setText("$"+getTotalAmt.get(pos));
imgLoader.DisplayImage(getDealImage.get(pos), holder.profile_image);
holder.FavBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (isNetworkAvailable()) {
if(!userid.equals("")){
Offer_ID = getDealID.get(pos);
GUsrFavState = getUserFav.get(pos);
if(GUsrFavState.equals("0")){
GUsrFavState="1";
getUserFav.remove(pos);
getUserFav.add(pos, "1");
holder.FavBtn.setBackgroundResource(R.drawable.fav_active_btn);
getBoolnState.set(pos, true);
new Call_OfferFavWS().execute();
}else{
GUsrFavState="0";
holder.FavBtn.setBackgroundResource(R.drawable.fav_btn);
getUserFav.remove(pos);
getUserFav.add(pos, "0");
getBoolnState.set(pos, false);
new Call_OfferFavWS().execute();
}
}else{
Intent CallSignIn = new Intent(DollarMainActivity.this,SingInActivity.class);
startActivity(CallSignIn);
}
} else {
Toast alrtMsg = Toast.makeText(DollarMainActivity.this, "No network connection available !!!", Toast.LENGTH_LONG);
alrtMsg.setGravity(Gravity.CENTER, 0, 0);
alrtMsg.show();
}
}
});
if(getBoolnState.get(pos)){
holder.FavBtn.setBackgroundResource(R.drawable.fav_active_btn);
}else{
holder.FavBtn.setBackgroundResource(R.drawable.fav_btn);
}
return view;
}
class ViewHolder {
public TextView DealName,ShopName;
public ImageView FavBtn, profile_image;
public LinearLayout listLayout;
public Button OfferAmtBtn;
}
}
希望它会对你有所帮助。
如果您需要任何帮助请告诉我。