Created
February 25, 2018 12:57
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Android ViewHolder pattern
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class CategoryAdapter(private val context: Context, private val categories: List<Category>) : BaseAdapter() { | |
override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View { | |
val categoryView : View | |
val holder : ViewHolder | |
if (convertView == null) { | |
categoryView = LayoutInflater.from(this.context).inflate(R.layout.category_list_item, null) | |
holder = ViewHolder() | |
holder.categoryImage = categoryView.findViewById(R.id.categoryImage) | |
holder.categoryName = categoryView.findViewById(R.id.categoryTitle) | |
categoryView.tag = holder | |
} else { | |
holder = convertView.tag as ViewHolder | |
categoryView = convertView | |
} | |
val category = this.categories[position] | |
val resourceId = this.context.resources.getIdentifier(category.image, "drawable", this.context.packageName) | |
holder.categoryImage?.setImageResource(resourceId) | |
holder.categoryName?.text = category.title | |
return categoryView | |
} | |
override fun getItem(position: Int): Category { | |
return this.categories[position] | |
} | |
override fun getItemId(position: Int): Long { | |
return 0 | |
} | |
override fun getCount(): Int { | |
return this.categories.count() | |
} | |
private class ViewHolder { | |
var categoryImage : ImageView? = null | |
var categoryName : TextView? = null | |
} | |
} |
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