android - 通过代码在Android中创建子菜单

Question

我在 Android 中使用 XML 文件 创建了一个子菜单。但我想使用编程代码来创建它。

是否可以创建？

如何实现？

谢谢。

Answer 1

此代码有效

import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.Toast;

/**
 * Class which shows how to work with Submenus
 *
 * @author FaYna Soft Labs
 */
public class Main extends Activity {

private static final int FILE = 0;
private static final int EDIT = 1;

private static final int NEW_MENU_ITEM = Menu.FIRST;
private static final int SAVE_MENU_ITEM = NEW_MENU_ITEM + 1;

private static final int UNDO_MENU_ITEM = SAVE_MENU_ITEM + 1;
private static final int REDO_MENU_ITEM = UNDO_MENU_ITEM + 1;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    SubMenu fileMenu = menu.addSubMenu("File");
    SubMenu editMenu = menu.addSubMenu("Edit");
    fileMenu.add(FILE, NEW_MENU_ITEM, 0, "new");
    fileMenu.add(FILE, SAVE_MENU_ITEM, 1, "save");
    editMenu.add(EDIT, UNDO_MENU_ITEM, 0, "undo");
    editMenu.add(EDIT, REDO_MENU_ITEM, 1, "redo");
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case NEW_MENU_ITEM:
        showMsg("New");
        break;
    case SAVE_MENU_ITEM:
        showMsg("Save");
        break;
    case UNDO_MENU_ITEM:
        showMsg("Undo");
        break;
    case REDO_MENU_ITEM:
        showMsg("Redo");
        break;
    }
    return super.onOptionsItemSelected(item);
}

private void showMsg(String message) {
    Toast msg = Toast.makeText(Main.this, message, Toast.LENGTH_LONG);
    msg.setGravity(Gravity.CENTER, msg.getXOffset() / 2,
            msg.getYOffset() / 2);
    msg.show();
}
}