android - 如何在选择时突出显示 GridView 项目？

Question

我正在创建一个带有图像和文本的 GridView 布局。我想要多选项目，但我想突出显示所选的网格项目。

这是我的代码:

public class FragMent1 extends Fragment{

        BaseAdapter MyAdapter;
    private Context mContext;

    @SuppressLint("ValidFragment")
    public FragMent1(Context c) {
        mContext = c;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        //View view = inflater.inflate(R.layout.g, null);
        View view = inflater.inflate(R.layout.gridview,null);
        final GridView listView = (GridView) view.findViewById(R.id.mainGrid);
        listView.setAdapter(new Adapter());
        //listView.setSelection(1);
        listView.setChoiceMode(GridView.CHOICE_MODE_MULTIPLE_MODAL);
        listView.setMultiChoiceModeListener(new MultiChoiceModeListener() {

            @Override
            public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
                // TODO Auto-generated method stub
                return false;
            }

            @Override
            public void onDestroyActionMode(ActionMode mode) {
                // TODO Auto-generated method stub

            }

            @Override
            public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                // TODO Auto-generated method stub

                mode.setTitle("Select Items");
                mode.setSubtitle("One item selected");
                return true;

            }

            @Override
            public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
                // TODO Auto-generated method stub


                int selectCount = listView.getCheckedItemCount();
                switch (selectCount) {
                case 1:
                    mode.setSubtitle("One item selected");

                    break;
                default:
                    mode.setSubtitle("" + selectCount + " items selected");

                    break;
                }

                return true;
            }

            @Override
            public void onItemCheckedStateChanged(ActionMode mode, int position,
                    long id, boolean checked) {
                // TODO Auto-generated method stub



                int selectCount = listView.getCheckedItemCount();
                switch (selectCount) {
                case 1:
                    mode.setSubtitle("One item selected");
                    break;
                default:
                    mode.setSubtitle("" + selectCount + " items selected");
                    break;
                }

            }
        });


        return view;
    }

    private class Adapter extends BaseAdapter {

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

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            View myView = convertView;

            ImageView image;
            if (convertView == null) {
                image = new ImageView(FragMent1.this.getActivity());
                image.setLayoutParams(new GridView.LayoutParams(85, 85));
                image.setScaleType(ImageView.ScaleType.CENTER_CROP);



                LayoutInflater inflater = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);           
                myView = inflater.inflate(R.layout.grid_items_ontap, null);


                // Add The Image!!!           
                ImageView iv = (ImageView)myView.findViewById(R.id.grid_item_image_OnTap);
                iv.setImageResource(mThumbIds[position]);


                // Add The Text!!!
                TextView tv = (TextView)myView.findViewById(R.id.grid_item_text_onTap);
                tv.setText(names[position] );






            }
            return myView;
        }

        private Integer[] mThumbIds = {
                R.drawable.car, R.drawable.car,
                R.drawable.car, R.drawable.car,
                R.drawable.car,R.drawable.car,R.drawable.car
        };

        private String[] names={"ab","cd","ef","gh","ij","kl","mn"};


    }
}

我应该在代码中添加什么来突出显示将被选中的网格项目。

请建议我一些方法来做到这一点。提前致谢。

Answer 1

1. 创建 ImageAdapter 类
2. 将这个参数添加到你的类中 private int selectedPosition = -1

3. 将此方法添加到您的 ImageAdapter 类中

   public void setSelectedPosition(int position) {
       selectedPosition = position;
   }
   

4. 将这些行添加到 ImageAdapter 类的 getView 方法的末尾

   if (position == selectedPosition) {
           gridView.setBackgroundColor(Color.BLACK);
       } else {
           gridView.setBackgroundColor(Color.TRANSPARENT);
       }
   

5. 在您的 Activity (或 fragment )中从 ImageAdapter 类创建对象

6. 然后只需添加这些行进行测试

   GridView gridView = (GridView) view.findViewById(R.id.gridview);
   gridView.setAdapter(adapterImage);
   gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
       public void onItemClick(AdapterView<?> parent, View v,
                               int position, long id) {
           adapterImage.setSelectedPosition(position);
           adapterImage.notifyDataSetChanged();
       }
   });