小编You*_*aga的帖子

你好,所以我创建了一个列表,我想添加操作栏.我对android很新,所以我想知道在使用ListActivity时如何添加操作栏.任何帮助将不胜感激.谢谢我的代码:

     public class MainActivity extends ListActivity {

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

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


        items.add(new SectionItem("2x2 Matrices"));
        items.add(new EntryItem("Adding 2 Matrices"));
        items.add(new EntryItem("Subtracting 2 Matrices"));
        items.add(new EntryItem("Multiplying 2 Matrices"));
        items.add(new EntryItem("Multiplying by a constant"));
        items.add(new EntryItem("Dividing 2 Matrices"));
        items.add(new EntryItem("Negative of a Matrix"));
        items.add(new EntryItem("Inverse of a Matrix"));
        items.add(new EntryItem("Determinant of a Matrix"));

        /*Section2*/
        items.add(new SectionItem("3x3 Matrices"));
        items.add(new EntryItem("Item 4"));
        items.add(new EntryItem("Item 5"));
        items.add(new EntryItem("Item 6"));
        items.add(new EntryItem("Item 7"));
        /*Section3*/
        items.add(new SectionItem("Category 3"));
        items.add(new EntryItem("Item …