在gridview中異步加載圖片

Question

目前我在使用宗海里的android-http-image-manager，但是我面臨的問題是當圖片下載時，當我滾動網格視圖列表時，圖像會顯示在其他一些網格單元格中。有人可以幫我解決這個問題..？

這是我的適配器類：

package com.syncusup.list.adapters; 

import java.io.File; 
import java.util.ArrayList; 

import android.app.Activity; 
import android.content.Context; 
import android.graphics.Bitmap; 
import android.net.Uri; 
import android.os.Environment; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.Filter; 
import android.widget.ImageView; 
import android.widget.TextView; 

import com.syncusup.R; 
import com.syncusup.UILApplication; 
import com.syncusup.httpimageloader.HttpImageManager; 
import com.syncusup.model.VCard; 
import com.syncusup.utils.SyncLocalDatabase; 

public class LocalContactsAdapter extends ArrayAdapter<VCard> { 

    private LayoutInflater mInflater; 

    private ArrayList<VCard> mOriginalList; 

    private ArrayList<VCard> mContactList; 

    private HttpImageManager mHttpImageManager; 

    private MyFilter mFilter; 

    private Context mContext; 

    private File aFileToCheck; 

    public LocalContactsAdapter(Context iContext, ArrayList<VCard> iVcardsArray) { 
     super(iContext, R.layout.localcontacts_row, iVcardsArray); 
     this.mContactList = new ArrayList<VCard>(); 
     this.mContactList.addAll(iVcardsArray); 
     this.mOriginalList = new ArrayList<VCard>(); 
     this.mOriginalList.addAll(iVcardsArray); 
     this.mContext = iContext; 
     mHttpImageManager = ((UILApplication)((Activity)mContext).getApplication()) 
       .getHttpImageManager(); 
    } 

    private class ViewHolder { 
     public TextView aContactName; 

     public TextView aContact; 

     public ImageView aContactImage; 
    } 

    @Override 
    public Filter getFilter() { 
     if (mFilter == null) { 
      mFilter = new MyFilter(); 
     } 
     return mFilter; 
    } 

    @Override 
    public int getPosition(VCard iItem) { 
     return super.getPosition(iItem); 
    } 

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

    @Override 
    public VCard getItem(int iPosition) { 
     return mContactList.get(iPosition); 
    } 

    @Override 
    public long getItemId(int iPosition) { 
     return iPosition; 
    } 

    @Override 
    public View getView(final int iPosition, View iConvertView, ViewGroup iParent) { 

     final ViewHolder aHolder; 
     aFileToCheck = new File(Environment.getExternalStorageDirectory() + "/SyncUsUp/", 
       SyncLocalDatabase.computeHashedName(mContactList.get(iPosition).getID())); 

     if (iConvertView == null || iConvertView.getTag() == null) { 
      // default layout inflater 
      mInflater = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      iConvertView = mInflater.inflate(R.layout.localcontacts_row, null); 
      aHolder = new ViewHolder(); 
      aHolder.aContactName = (TextView)iConvertView.findViewById(R.id.tvMyContactName); 
      aHolder.aContact = (TextView)iConvertView.findViewById(R.id.tvMyContact); 
      aHolder.aContactImage = (ImageView)iConvertView.findViewById(R.id.ivContact); 
      iConvertView.setTag(aHolder); 
     } else { 
      aHolder = (ViewHolder)iConvertView.getTag(); 
     } 

     ImageView aImageView = aHolder.aContactImage; 
     aImageView.setImageResource(R.drawable.contact_box_blanktile); 

     try { 
      if (mContactList.get(iPosition).getPhoto() != null) { 
       Bitmap aBitmap = mHttpImageManager.loadImage(new HttpImageManager.LoadRequest(Uri 
         .parse(mContactList.get(iPosition).getPhoto().getUrl()), aImageView)); 
       if (aBitmap != null) { 
        aImageView.setImageBitmap(aBitmap); 
       } 
      } else if (aFileToCheck.exists()) { 
       Bitmap aBitmap = mHttpImageManager.loadImage(new HttpImageManager.LoadRequest(Uri 
         .parse(mContactList.get(iPosition).getID()), aImageView)); 
       if (aBitmap != null) { 
        aImageView.setImageBitmap(aBitmap); 
       } 

      } 
     } catch (Exception iException) { 
      iException.printStackTrace(); 
     } 

     if (mContactList.get(iPosition).getFullName() != null) { 
      aHolder.aContactName.setText(mContactList.get(iPosition).getFullName()); 
     } else { 
      aHolder.aContactName.setText("No Name"); 
     } 

     return iConvertView; 
    } 

    private class MyFilter extends Filter { 

     @Override 
     protected FilterResults performFiltering(CharSequence iConstraint) { 

      FilterResults aResult = null; 
      try { 
       iConstraint = iConstraint.toString().toLowerCase(); 
       aResult = new FilterResults(); 
       if (iConstraint != null && iConstraint.toString().length() > 0) { 
        ArrayList<VCard> aFilteredItems = new ArrayList<VCard>(); 

        for (int i = 0, l = mOriginalList.size(); i < l; i++) { 
         VCard aList = mOriginalList.get(i); 
         if (aList.getFullName() != null) { 
          if (aList.getFullName().toString().toLowerCase().contains(iConstraint)) 
           aFilteredItems.add(aList); 
         } 
        } 
        aResult.count = aFilteredItems.size(); 
        aResult.values = aFilteredItems; 
       } else { 
        synchronized (this) { 
         aResult.values = mOriginalList; 
         aResult.count = mOriginalList.size(); 
        } 
       } 
      } catch (Exception iException) { 
       iException.printStackTrace(); 
      } 
      return aResult; 
     } 

     @SuppressWarnings("unchecked") 
     @Override 
     protected void publishResults(CharSequence iConstraint, FilterResults iResults) { 
      try { 
       mContactList = (ArrayList<VCard>)iResults.values; 
       notifyDataSetChanged(); 
       clear(); 
       for (int i = 0, l = mContactList.size(); i < l; i++) 
        add(mContactList.get(i)); 
       notifyDataSetInvalidated(); 
      } catch (Exception iException) { 
       iException.printStackTrace(); 
      } 
     } 
    } 
} 

Answer 1

此問題是由於觀看由網格重用。也就是說，用於顯示網格第一頁數據的視圖在被調用時被重用以顯示數據。實際上，圖像下載庫應該處理這個改變並且正確地執行。最好去另一個圖書館來延遲加載圖像。