Question

我有一个ListView，我设法在其上显示许多文本。部分文本格式为 BOLD 。为了使这些文本变得粗体，我使用了Spannable并且它有效！但是，当我向下滚动它时，索引[0]变为多个。

为了避免那个场景，我使用了一个持有人来保存我的TextViews。我设法在滚动中解决了这个问题，但由于某些原因，文本样式是BOLD，在我的ListView中消失了。我怎么能这样做？

MainActivity.java

private void populateListView() {

String[] source = { "Lorem ipsum dolor sit amet", "consectetuer adipiscing elit",
                    "sed diam nonummy nibh " };

final SpannableString out0 = new SpannableString(source[0]);
final SpannableString out2 = new SpannableString(source[2]);

StyleSpan boldSpan = new StyleSpan(Typeface.BOLD);

out0.setSpan(boldSpan, 6, 17, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
out2.setSpan(boldSpan, 0, 8, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
            R.layout.items, // Layout to use (create)
            source) { // Items to be displayed

        public View getView(int position, View convertView, ViewGroup parent) {
            View v = super.getView(position, convertView, parent);

            try {

                viewHolder.tv = (TextView) lv_procedures.getChildAt(0)
                        .findViewById(R.id.lbl_item);
                viewHolder.tv_2 = (TextView) lv_procedures.getChildAt(2)
                        .findViewById(R.id.lbl_item);

                viewHolder.tv.setText(out0);
                viewHolder.tv_2.setText(out2);

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

            return v;
        }
    };


}

Class ViewHolder

private class ViewHolder {
    TextView tv;
    TextView tv_2;
}

Answer 1

创建自定义适配器并实现ViewHolder模式以维护List每个项目状态：

class CustomAdapter extends ArrayAdapter<String>{
        private Context context;
        private String[] source;
        public CustomAdapter(Context context, String[] source) {
            super(context,R.layout.items,source);
            this.context = context;
            this.source = source;
        }

        @Override
        public int getCount() {
            return source.length;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder;
            if(convertView==null){
                convertView = LayoutInflater.from(context).inflate(R.layout.items,null);
                holder = new ViewHolder();
                holder.tv = (TextView) convertView.findViewById(R.id.lbl_item);
                convertView.setTag(holder);
            }else{
                holder = (ViewHolder)convertView.getTag();
            }

            if(position==0){
                final SpannableString out0 = new SpannableString(source[position]);
                StyleSpan boldSpan = new StyleSpan(Typeface.BOLD);
                out0.setSpan(boldSpan, 6, 17, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
                holder.tv.setText(out0);

            }else if(position==2){
                final SpannableString out2 = new SpannableString(source[position]);
                StyleSpan boldSpan = new StyleSpan(Typeface.BOLD);
                out2.setSpan(boldSpan, 0, 8, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
                holder.tv.setText(out2);
            }else{
                holder.tv.setText(source[position]);
            }


            convertView.setTag(holder);
            return convertView;
        }

        private class ViewHolder {
            TextView tv;
        }
    }

在Android中将字符串数组设置为粗体

1 个答案: