Question

嗨我有静态列表视图，我有一个共同的ImageView作为一个图标。我想只为前两项添加图标而不做任何事。如何通过拥有共同的图像占位符来实现这一点？以下是我的代码：

的ListView

public class SectionListExampleActivity extends ListActivity {
    /** Called when the activity is first created. */

     ArrayList<Item> items = new ArrayList<Item>();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


        items.add(new SectionItem("Category 1"));
        items.add(new EntryItem("Item 1", "This is item 1.1"));
        items.add(new EntryItem("Item 2", "This is item 1.2"));
        items.add(new EntryItem("Item 3", "This is item 1.3"));


        items.add(new SectionItem("Category 2"));
        items.add(new EntryItem("Item 4", "This is item 2.1"));
        items.add(new EntryItem("Item 5", "This is item 2.2"));
        items.add(new EntryItem("Item 6", "This is item 2.3"));
        items.add(new EntryItem("Item 7", "This is item 2.4"));

        items.add(new SectionItem("Category 3"));
        items.add(new EntryItem("Item 8", "This is item 3.1"));
        items.add(new EntryItem("Item 9", "This is item 3.2"));
        items.add(new EntryItem("Item 10", "This is item 3.3"));
        items.add(new EntryItem("Item 11", "This is item 3.4"));
        items.add(new EntryItem("Item 12", "This is item 3.5"));

        EntryAdapter adapter = new EntryAdapter(this, items);

        setListAdapter(adapter);
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {

        if(!items.get(position).isSection()){

            EntryItem item = (EntryItem)items.get(position);

            Toast.makeText(this, "You clicked " + item.title , Toast.LENGTH_SHORT).show();


        }

        super.onListItemClick(l, v, position, id);
    }
}

EntryAdapter

public class EntryAdapter extends ArrayAdapter<Item> {

    private Context context;
    private ArrayList<Item> items;
    private LayoutInflater vi;

    public EntryAdapter(Context context,ArrayList<Item> items) {
        super(context,0, items);
        this.context = context;
        this.items = items;
        vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }


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

        final Item i = items.get(position);
        if (i != null) {
            if(i.isSection()){
                SectionItem si = (SectionItem)i;
                v = vi.inflate(R.layout.list_item_section, null);

                v.setOnClickListener(null);
                v.setOnLongClickListener(null);
                v.setLongClickable(false);

                final TextView sectionView = (TextView) v.findViewById(R.id.list_item_section_text);
                sectionView.setText(si.getTitle());
            }else{
                EntryItem ei = (EntryItem)i;
                v = vi.inflate(R.layout.list_item_entry, null);
                final TextView title = (TextView)v.findViewById(R.id.list_item_entry_title);
                final TextView subtitle = (TextView)v.findViewById(R.id.list_item_entry_summary);

                if (title != null) 
                    title.setText(ei.title);
                if(subtitle != null)
                    subtitle.setText(ei.subtitle);
            }
        }
        return v;
    }

}

布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:minHeight="?android:attr/listPreferredItemHeight"
    android:gravity="center_vertical"
    android:paddingRight="?android:attr/scrollbarSize">

    <ImageView
        android:id="@+id/list_item_entry_drawable"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:src="@android:drawable/ic_menu_preferences"
        android:paddingLeft="9dp"/>

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dip"
        android:layout_marginRight="6dip"
        android:layout_marginTop="6dip"
        android:layout_marginBottom="6dip"
        android:layout_weight="1">

        <TextView android:id="@+id/list_item_entry_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:singleLine="true"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:ellipsize="marquee"
            android:fadingEdge="horizontal" />

        <TextView android:id="@+id/list_item_entry_summary"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/list_item_entry_title"
            android:layout_alignLeft="@id/list_item_entry_title"
            android:textAppearance="?android:attr/textAppearanceSmall"
            android:singleLine="true"
            android:textColor="?android:attr/textColorSecondary" />

    </RelativeLayout>

</LinearLayout>

Answer 1

在getView方法中，您已拥有该职位。

所以你可以做到

if (position < 2) {
    // show image
} else {
    // remove image using setVisibility(View.GONE)
}

Answer 2

根据上面的评论，这是一个示例实现（这在你的else里面......相应地放置它）：

...
...
final ImageView imageicon = (ImageView)v.findViewById(R.id.list_item_entry_drawable);

if(subtitle != null)
    subtitle.setText(ei.subtitle);          

if(position == 1 || position ==2) {
    // this will show the image icon for the first and second view
    imageicon.setVisibility(View.VISIBLE);
    // now set the icon to the image view here..
    // imageicon.setImageResource(R.drawable.ok);
}
else {
    // this will hide the image icon, optional if you want
    imageicon.setVisibility(View.GONE);
}
...
...

如何仅为ListView中的前两个列表项设置静态图标

2 个答案: