备用颜色在动态列表视图中滚动期间更改其位置

Question

if (convertView == null) {
            vh = new ViewHolder();
            convertView = inflater.inflate(R.layout.search_dtl_grid, parent, false);

        //  vh.llMain = (LinearLayout) convertView.findViewById(R.id.sdg_ll_main);
            if (pos % 2 == 0) {
                convertView.setBackgroundColor(Color.parseColor("#A4A4A4"));
            } else{
                convertView.setBackgroundColor(Color.parseColor("#FFFFFF"));
            }

I have tried the above code in adapter The list is coming with alternate color but when we scroll down the color changes its position like first they are coming grey white grey white but after scrolling it up or down it comes grey grey white grey white white like that , i have searched this many solution are given in that they are saying to add else part for second color i have already done that but still no success. Please provide me wih a good solution. thanks

Answer 1

When you use the ViewHolder pattern in a ListView (something that you should do) you have to understand it first.

Android reuses the views you have already inflated. So you have to distinguish two scenarios:

• The view you are using is not inflated
• The view you are using is some one you already inflated and is being reused

In the first case you have to inflate the view, create a ViewHolder and set it as the view's tag.

In the second case the only thing you have to do is recover the ViewHolder object.

After that, work with the ViewHolder . Take a look at this example .

In your concrete case, the solution will be something like:

if (convertView == null) {
    inflateView(...);
    createViewHolder(...);
} else {
    recoverViewHolder(...);
}

if (pos % 2 == 0) {
    convertView.setBackgroundColor(Color.parseColor("#A4A4A4"));
} else{
    convertView.setBackgroundColor(Color.parseColor("#FFFFFF"));
}