实现选项菜单

//onCreateOptionsMenu()创建选项菜单
--设置菜单项可用代码动态设置menu.add();

--通过xml设置MenuInflater.inflate()

// onOptionsItemSelected(MenuItem item)设置菜单点击事件

---

• 1. 通过xml设置MenuInflater.inflate()

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.menu_item1:
            Toast.makeText(MainActivity.this, "点击菜单一",Toast.LENGTH_SHORT).show();
            break;
        case R.id.menu_item2:
            Toast.makeText(MainActivity.this, "点击菜单二",Toast.LENGTH_SHORT).show();
            break;

        }
        return super.onOptionsItemSelected(item);
    }

menu目录下：
main.xml文件

    <item
        android:id="@+id/menu_item1"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="菜单一"/>
    <item
        android:id="@+id/menu_item2"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="菜单二"/>

• 2. 通过xml设置MenuInflater.inflate()

public boolean onCreateOptionsMenu(Menu menu) {
        //menu.add(groupId, itemId, order, title)
        menu.add(1, 101, 1,"菜单一");
        menu.add(1, 102, 1,"菜单二");
        menu.add(1, 103, 1,"菜单三");
        menu.add(1, 104, 1,"菜单四");
        return true;
    
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        /*switch (item.getItemId()) {
        case R.id.menu_item1:
            Toast.makeText(MainActivity.this, "点击菜单一",Toast.LENGTH_SHORT).show();
            break;
        case R.id.menu_item2:
            Toast.makeText(MainActivity.this, "点击菜单二",Toast.LENGTH_SHORT).show();
            break;

        }*/
        
        switch (item.getItemId()) {
        case 103:
            Toast.makeText(MainActivity.this, "点击菜单三",Toast.LENGTH_SHORT).show();
            break;

        case 101:
            Toast.makeText(MainActivity.this, "点击菜单一",Toast.LENGTH_SHORT).show();
            break;
        case 102:
            Toast.makeText(MainActivity.this, "点击菜单二",Toast.LENGTH_SHORT).show();
            break;
        }
        return super.onOptionsItemSelected(item);
    }

界面.png

如要实现某选项跳转功能---修改代码：

    case 101:
        Intent  intent=new Intent(MainActivity.this, SecondActivity.class);
        item.setIntent(intent);