【达内课程】OptionsMenu

OptionsMenu：选项菜单

orderInCategory是排序，由小到大排序，如果数字相同，按照代码先后顺序显示

栗子：通过xml创建一个选项菜单

MenuActivity

public class MenuActivity extends AppCompatActivity {

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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main,menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case R.id.action_file:
                Toast.makeText(this,"点击了File",Toast.LENGTH_SHORT).show();
                break;
            case R.id.action_edit:
                Toast.makeText(this,"点击了Edit",Toast.LENGTH_SHORT).show();
                break;
            case R.id.action_view:
                Toast.makeText(this,"点击了View",Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onOptionsItemSelected(item);
    }
}

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/action_file"
        android:orderInCategory="100"
        app:showAsAction="never"
        android:title="File"/>
    <item
        android:id="@+id/action_edit"
        android:orderInCategory="100"
        app:showAsAction="never"
        android:title="Edit"/>
    <item
        android:id="@+id/action_view"
        android:orderInCategory="100"
        app:showAsAction="never"
        android:title="View"/>
</menu>

效果

由于有的模拟机已经没有了Menu键，可以使用Ctrl+M快捷键来实现
点击了Menu键

动态添加菜单

方法menu.add(groupid,itemid,order,title);

其中groupid，是分组id，比如Android Studio中的菜单，可以看出明显的分组

但是由于安卓中的分组没有明显的效果，这里我们都给0

itemid是不能冲突的，因为我们一会要通过item.getItemId()来获得itemid来进行响应

order是排序

title就是最后显示的文字

栗子：通过代码动态添加菜单

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //getMenuInflater().inflate(R.menu.main,menu);
        menu.add(0,1,0,"Navigate");
        menu.add(0,2,0,"Code");
        menu.add(0,3,0,"Analyze");
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case 1:
                Toast.makeText(this,"点击了Navigate",Toast.LENGTH_SHORT).show();
                break;
            case 2:
                Toast.makeText(this,"点击了Code",Toast.LENGTH_SHORT).show();
                break;
            case 3:
                Toast.makeText(this,"点击了Analyze",Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onOptionsItemSelected(item);
    }

效果和刚才是相同的

对刚才写的代码进行优化

public static final int MENU_ITEM_NAVIGATE = 1;
    public static final int MENU_ITEM_CODE = 2;
    public static final int MENU_ITEM_ANALYZE = 3;
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //getMenuInflater().inflate(R.menu.main,menu);
        menu.add(Menu.NONE,MENU_ITEM_NAVIGATE,Menu.NONE,"Navigate");
        menu.add(Menu.NONE,MENU_ITEM_CODE,Menu.NONE,"Code");
        menu.add(Menu.NONE,MENU_ITEM_ANALYZE,Menu.NONE,"Analyze");
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case MENU_ITEM_NAVIGATE:
                Toast.makeText(this,"点击了Navigate",Toast.LENGTH_SHORT).show();
                break;
            case MENU_ITEM_CODE:
                Toast.makeText(this,"点击了Code",Toast.LENGTH_SHORT).show();
                break;
            case MENU_ITEM_ANALYZE:
                Toast.makeText(this,"点击了Analyze",Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onOptionsItemSelected(item);
    }

栗子：通过xml添加子菜单

修改menu菜单文件

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/action_file"
        android:orderInCategory="100"
        app:showAsAction="never"
        android:title="File">
        <menu>
            <item
                android:id="@+id/action_new"
                android:orderInCategory="100"
                app:showAsAction="never"
                android:title="New"/>
            <item
                android:id="@+id/action_open"
                android:orderInCategory="100"
                app:showAsAction="never"
                android:title="Open"/>
        </menu>
    </item>
    <item
        android:id="@+id/action_edit"
        android:orderInCategory="100"
        app:showAsAction="never"
        android:title="Edit"/>
    <item
        android:id="@+id/action_view"
        android:orderInCategory="100"
        app:showAsAction="never"
        android:title="View"/>
</menu>

栗子：通过程序添加子菜单

刚才的代码

menu.add(Menu.NONE,MENU_ITEM_NAVIGATE,Menu.NONE,"Navigate");

通过add添加的菜单是一级菜单，不能拥有子菜单

通过menu.addSubMenu()添加的菜单能拥有子菜单

 public static final int MENU_ITEM_NAVIGATE = 1;
    public static final int MENU_ITEM_CODE = 2;
    public static final int MENU_ITEM_ANALYZE = 3;
    public static final int MENU_ITEM_INSPECT_CODE = 4;
    public static final int MENU_ITEM_CODE_CLEANUP = 5;
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //getMenuInflater().inflate(R.menu.main,menu);
        menu.add(Menu.NONE,MENU_ITEM_NAVIGATE,Menu.NONE,"Navigate");
        menu.add(Menu.NONE,MENU_ITEM_CODE,Menu.NONE,"Code");
        SubMenu subMenu = menu.addSubMenu(Menu.NONE, MENU_ITEM_ANALYZE, Menu.NONE, "Analyze");
        subMenu.add(Menu.NONE,MENU_ITEM_INSPECT_CODE,Menu.NONE,"Inspect Code");
        subMenu.add(Menu.NONE,MENU_ITEM_CODE_CLEANUP,Menu.NONE,"Code Cleanup");
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case MENU_ITEM_NAVIGATE:
                Toast.makeText(this,"点击了Navigate",Toast.LENGTH_SHORT).show();
                break;
            case MENU_ITEM_CODE:
                Toast.makeText(this,"点击了Code",Toast.LENGTH_SHORT).show();
                break;
            /*case MENU_ITEM_ANALYZE:
                Toast.makeText(this,"点击了Analyze",Toast.LENGTH_SHORT).show();
                break;*/
            case MENU_ITEM_INSPECT_CODE:
                Toast.makeText(this,"点击了Inspect Code",Toast.LENGTH_SHORT).show();
                break;
            case MENU_ITEM_CODE_CLEANUP:
                Toast.makeText(this,"点击了Code Cleanup",Toast.LENGTH_SHORT).show();
                break;
            /*case R.id.action_file:
                Toast.makeText(this,"点击了File",Toast.LENGTH_SHORT).show();
                break;*/
            case R.id.action_edit:
                Toast.makeText(this,"点击了Edit",Toast.LENGTH_SHORT).show();
                break;
            case R.id.action_view:
                Toast.makeText(this,"点击了View",Toast.LENGTH_SHORT).show();
                break;
            case R.id.action_new:
                Toast.makeText(this,"点击了New",Toast.LENGTH_SHORT).show();
                break;
            case R.id.action_open:
                Toast.makeText(this,"点击了Open",Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onOptionsItemSelected(item);
    }