Question

如何在片段中更改ListView的特定项？我的问题是以下方法不起作用。特别是：

getViewByPosition(highLightLastSee(), lvItems).setBackgroundColor(bgColor);

拥有一个实现ListView的Fragment。我在Fragmentclass中有这个ListView的全局引用，我想更改ListView项的背景颜色

片段中的onCreateView方法

ListView lvItems;
View rootView;
FontsAdapter todoAdapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
DB_Helper = new DataBase(getActivity());
DB_Helper.open();
     rootView = inflater.inflate(R.layout.fragment_layout_main, container, false);

    lvItems = (ListView) rootView.findViewById(android.R.id.list);



    text_portrait_width_300 = (TextView) 
   rootView.findViewById(R.id.text_portrait_width_300);
    text_portrait_width_500_300 = (TextView) 
    rootView.findViewById(R.id.text_portrait_width_500_300);
    text_portrait_width_500 = (TextView) 
    rootView.findViewById(R.id.text_portrait_width_500);



    image_portrait_width_300 = (ImageView) rootView.findViewById(R.id.image_portrait_width_300);
    image_portrait_width_500_300 = (ImageView) rootView.findViewById(R.id.image_portrait_width_500_300);
    image_portrait_width_500 = (ImageView) rootView.findViewById(R.id.image_portrait_width_500);

    image_portrait = (ImageView) rootView.findViewById(R.id.image_portrait);
    text_portrait = (TextView) rootView.findViewById(R.id.text_portrait);

    text_landscape = (TextView) rootView.findViewById(R.id.text_landscape);
    image_landscape = (ImageView) rootView.findViewById(R.id.image_landscape);


    return rootView;


}

方法getView

public View getViewByPosition(int pos, ListView listView) {
final int firstListItemPosition = listView.getFirstVisiblePosition();
final int lastListItemPosition = firstListItemPosition + 
listView.getChildCount() - 1;

    if (pos < firstListItemPosition || pos > lastListItemPosition ) {
        return listView.getAdapter().getView(pos, null, listView);
    } else {
        final int childIndex = pos - firstListItemPosition;

        return listView.getChildAt(childIndex);
    }
}

public void updateBackgroundItem() {

    if(lvItems != null){

        int alpha = 14; //50% transparency
        int color = 245; //Your color value
        //int bgColor = Color.rgb(255,215,0);
        int bgColor = Color.argb(alpha, Color.red(color), Color.green(color), Color.blue(color));

        //ColorDrawable colorDrawable1 = new ColorDrawable(Color.parseColor("#A0A3A0"));

        Toast.makeText(getActivity(), "The position item to change BackgroundColor on listView "+highLightLastSee()+"", Toast.LENGTH_SHORT).show();

        getViewByPosition(highLightLastSee(), lvItems).setBackgroundColor(bgColor);

todoAdapter.notifyDataSetChanged();

    }

    else {

Toast.makeText(getActivity(), "Nothing lvItems ", 
Toast.LENGTH_SHORT).show();
    }
}

方法whereShowItems

public void whereShowItemsFromListView() {
lvItems.setAdapter(todoAdapter);

if(highLightLastSee() == -1){

Toast.makeText(getActivity(), "Item position is null", 
Toast.LENGTH_SHORT).show();

}

 else {

updateBackgroundItem();


}


}

如何在Fragment上更改listview中的特定项？

0 个答案: