List items position repeating in getview

问题:

I am creating a custom list view using baseadapter.i have 10 list item in my list.my problem is that afetr 6 items ,the first 4 are repeating.i just printed position values in getview.it gives 0,1,2,3,4,5,6,7,8,9,0,1,2,3.My code is below.

thanx in advance

public class ProductListAdapter extends BaseAdapter  implements OnClickListener{    

/*
 * developer :sanu
 * date :10-4-2013
 * time :3.34 pm
 */
public View row;
private String[] productName;
private String[] producttype;
private String[] priceRangeFrom;
private String[] priceRangeTo;
private String[] productImage;
private Activity activity;
private static LayoutInflater inflater=null;
static String posClicked;
ViewHolder holder;
Integer height1;
Integer width1;
Typeface tf;
Integer FirmaCount;
public ImageLoader imageLoader; 
public ProductListAdapter(Activity a,String[] name,String[] type,String[] price_from,String[] price_to,String[] image,Typeface tf) {
    activity    =  a;
    productName = name;
    producttype = type;
    priceRangeFrom = price_from;
    priceRangeTo = price_to;
    productImage = image;       
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);  
    imageLoader=new ImageLoader(activity.getApplicationContext());
}
public int getCount() {
    return productName.length;
}
public Object getItem(int position) {
    return position;
}
public long getItemId(int position) {
    return position;
} 
public int getViewTypeCount (int position)
{
    return position;
}
public static class ViewHolder{
    public TextView nameProduct;
    public TextView typeProduct;
    public TextView priceRangeProduct;
    public ImageView productImage;
    public ImageView plusImage;
    public RelativeLayout mainLayout;
    public int position;  
}
public View getView(int position, View convertView, ViewGroup parent) {     
    if(convertView == null){            
        convertView = inflater.inflate(R.layout.product_list_details,parent, false);
        holder=new ViewHolder();
        holder.nameProduct =(TextView)convertView.findViewById(R.id.name);
        holder.typeProduct =(TextView)convertView.findViewById(R.id.product);
        holder.priceRangeProduct =(TextView)convertView.findViewById(R.id.pricerange);
        holder.productImage =(ImageView)convertView.findViewById(R.id.image);
        holder.plusImage =(ImageView)convertView.findViewById(R.id.dot);
        holder.mainLayout = (RelativeLayout)convertView.findViewById(R.id.mainlayout);
        holder.nameProduct.setText(productName[position]);      
        if(producttype[position].length()>18)
        {
            holder.typeProduct.setText(producttype[position].substring(0,18)+"...");
        }
        else
        {
            holder.typeProduct.setText(producttype[position]);
        }
        holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,priceRangeFrom[position].length()-2)+" To "+priceRangeTo[position].substring(0, priceRangeTo[position].length()-2));          
        imageLoader.DisplayImage(productImage[position], holder.productImage);
        convertView.setTag(holder);                     
    }
    else
    {           
        holder = (ViewHolder)convertView.getTag();

    }       
    holder.plusImage.setTag(Integer.toString(position));
    holder.plusImage.setOnClickListener(this);  
    holder.mainLayout.setTag(Integer.toString(position));
    holder.mainLayout.setOnClickListener(this); 
    return convertView;
} 

回答1:

This sounds like a case of View re-cyclcing. Android will pass a pre-populated view to the getView method. It does so to minimize object creation. When an existing row-view is scrolled off screen, Android might try to recycle that view to display a row that is now on-screen. You need to account for the fact that this view may have been used to display data for another row (which is now off screen).

You have the following line

holder.typeProduct.setText

within the following conditional:

if(convertView == null){            

Move that line outside of the conditional, and all should be well.

回答2:

It's like EJK said. You are not recycling your view correctly. Change your code to this and notice where I put the setText calls

public View getView(int position, View convertView, ViewGroup parent) {     
if(convertView == null){            
    convertView = inflater.inflate(R.layout.product_list_details,parent, false);
    holder=new ViewHolder();
    holder.nameProduct =(TextView)convertView.findViewById(R.id.name);
    holder.typeProduct =(TextView)convertView.findViewById(R.id.product);
    holder.priceRangeProduct =(TextView)convertView.findViewById(R.id.pricerange);
    holder.productImage =(ImageView)convertView.findViewById(R.id.image);
    holder.plusImage =(ImageView)convertView.findViewById(R.id.dot);
    holder.mainLayout = (RelativeLayout)convertView.findViewById(R.id.mainlayout);

    convertView.setTag(holder);                     
}
else
{           
    holder = (ViewHolder)convertView.getTag();

}       
    holder.plusImage.setTag(Integer.toString(position));
    holder.plusImage.setOnClickListener(this);  
    holder.mainLayout.setTag(Integer.toString(position));
    holder.mainLayout.setOnClickListener(this); 

    //setText functions are here
    holder.nameProduct.setText(productName[position]); 


    if(producttype[position].length()>18)
    {
        holder.typeProduct.setText(producttype[position].substring(0,18)+"...");
    }
    else
    {
        holder.typeProduct.setText(producttype[position]);
    }
    holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,priceRangeFrom[position].length()-2)+" To "+priceRangeTo[position].substring(0, priceRangeTo[position].length()-2));

    imageLoader.DisplayImage(productImage[position], holder.productImage);

    return convertView;
} 

回答3:

Change your getView to

public View getView(int position, View convertView, ViewGroup parent) {     
    if(convertView == null){            
        convertView = inflater.inflate(R.layout.product_list_details,parent, false);
        holder=new ViewHolder();
        holder.nameProduct =(TextView)convertView.findViewById(R.id.name);
        holder.typeProduct =(TextView)convertView.findViewById(R.id.product);
        holder.priceRangeProduct =(TextView)convertView.findViewById(R.id.pricerange);
        holder.productImage =(ImageView)convertView.findViewById(R.id.image);
        holder.plusImage =(ImageView)convertView.findViewById(R.id.dot);
        holder.mainLayout = (RelativeLayout)convertView.findViewById(R.id.mainlayout);
        convertView.setTag(holder); 
        } else { 
         holder = (ViewHolder) convertView.getTag();
        } 
        holder.nameProduct.setText(productName[position]);      
        if(producttype[position].length()>18)
        {
            holder.typeProduct.setText(producttype[position].substring(0,18)+"...");
        }
        else
        {
            holder.typeProduct.setText(producttype[position]);
        }
        holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,priceRangeFrom[position].length()-2)+" To "+priceRangeTo[position].substring(0, priceRangeTo[position].length()-2));          
        imageLoader.DisplayImage(productImage[position], holder.productImage);

       holder.plusImage.setTag(Integer.toString(position));
       holder.plusImage.setOnClickListener(this);  
       holder.mainLayout.setTag(Integer.toString(position));
       holder.mainLayout.setOnClickListener(this); 
       return convertView;
} 

Also check this

How ListView's recycling mechanism works

回答4:

Change getView()

Declare ViewHolder before if (convertView == null)

@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = inflater.inflate(R.layout.product_list_details,
                    parent, false);
            holder = new ViewHolder();
            holder.nameProduct = (TextView) convertView.findViewById(R.id.name);
            holder.typeProduct = (TextView) convertView
                    .findViewById(R.id.product);
            holder.priceRangeProduct = (TextView) convertView
                    .findViewById(R.id.pricerange);
            holder.productImage = (ImageView) convertView
                    .findViewById(R.id.image);
            holder.plusImage = (ImageView) convertView.findViewById(R.id.dot);
            holder.mainLayout = (RelativeLayout) convertView
                    .findViewById(R.id.mainlayout);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();

        }
        holder.nameProduct.setText(productName[position]);
        if (producttype[position].length() > 18) {
            holder.typeProduct.setText(producttype[position].substring(0, 18)
                    + "...");
        } else {
            holder.typeProduct.setText(producttype[position]);
        }
        holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,
                priceRangeFrom[position].length() - 2)
                + " To "
                + priceRangeTo[position].substring(0,
                        priceRangeTo[position].length() - 2));
        imageLoader.DisplayImage(productImage[position], holder.productImage);
        holder.plusImage.setTag(Integer.toString(position));
        holder.plusImage.setOnClickListener(this);
        holder.mainLayout.setTag(Integer.toString(position));
        holder.mainLayout.setOnClickListener(this);
        return convertView;
    }