Android中菜单的使用

怼烎@ 2022-07-28 00:27 137阅读 0赞

## 一、使用代码设置菜单 ##

### 1.设置选项菜单和子菜单 ###

> **实现思路：**  
> 1.重写onCreateOptionsMenu(Menu menu)方法来添加菜单项或者子菜单  
> 2.重写onOptionsItemSelected(MenuItem item)方法来设置菜单的响应事件

*  代码文件

public class MainActivity extends AppCompatActivity { 
    
        final int FONT_10 = 0x111;
        final int FONT_12 = 0x112;
        final int FONT_14 = 0x113;
        final int FONT_16 = 0x114;
        final int FONT_18 = 0x115;
    
        final int PLAIN_ITEM = 0x11b;
    
        final int FONT_RED = 0x116;
        final int FONT_BLUE = 0x117;
        final int FONT_GREEN = 0x118;
    
        EditText editText;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            editText = (EditText) findViewById(R.id.editText);
        }
    
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            //设置可以设置子菜单的菜单项
            SubMenu fontMenu = menu.addSubMenu("字体大小");
            //为菜单项设置图标
            fontMenu.setIcon(R.mipmap.ic_launcher);
    
            fontMenu.setHeaderIcon(R.mipmap.ic_launcher);
            //为菜单项设置标题
            fontMenu.setHeaderTitle("选择字体大小");
            //添加子菜单
            fontMenu.add(0, FONT_10, 0, "10号字体");
            fontMenu.add(0, FONT_12, 0, "12号字体");
            fontMenu.add(0, FONT_14, 0, "14号字体");
            fontMenu.add(0, FONT_16, 0, "16号字体");
            fontMenu.add(0, FONT_18, 0, "18号字体");
    
            //添加一个普通子菜单项
            menu.add(0, PLAIN_ITEM, 0, "普通菜单项");
            MenuItem start = fontMenu.add("启动");
            start.setIntent(new Intent(MainActivity.this, Other.class));
    
            SubMenu colorMenu = menu.addSubMenu("字体颜色");
            colorMenu.setIcon(R.mipmap.ic_launcher);
            colorMenu.setHeaderIcon(R.mipmap.ic_launcher);
            colorMenu.setHeaderTitle("选择文字颜色");
            colorMenu.add(0, FONT_RED,0,"红色");
            colorMenu.add(0, FONT_BLUE,0,"蓝色");
            colorMenu.add(0, FONT_GREEN,0,"绿色");
    
            return super.onCreateOptionsMenu(menu);
        }
    
    
        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            switch (item.getItemId()) {
                case FONT_10:
                    editText.setTextSize(10 * 2);
                    break;
                case FONT_12:
                    editText.setTextSize(12 * 2);
                    break;
                case FONT_14:
                    editText.setTextSize(14 * 2);
                    break;
                case FONT_16:
                    editText.setTextSize(16 * 2);
                    break;
                case FONT_18:
                    editText.setTextSize(18 * 2);
                    break;
                case FONT_RED:
                    editText.setTextColor(Color.RED);
                    break;
                case FONT_GREEN:
                    editText.setTextColor(Color.GREEN);
                    break;
                case FONT_BLUE:
                    editText.setTextColor(Color.BLUE);
                    break;
    
                case PLAIN_ITEM:
                    break;
            }
            return true;
        }
    }

--------------------

### 2.设置上下文菜单 ###

> 上下文菜单可以绑定一个控件，长按该控件会弹出上下文菜单，
> 
> **实现思路：**  
> 1.重写onCreateContextMenu(ContextMenu menu,View view,ContextMenuInfo menuInfo)方法  
> 2.调用registerForContextMenu(View view)方法为组件注册上下文菜单  
> 3.重写onContextItemSelected(MenuItem item)方法为其设置响应事件

*  代码文件

public class MainActivity extends AppCompatActivity { 
    
        final int MENU1 = 0x111;
        final int MENU2 = 0x112;
        final int MENU3 = 0x113;
    
        TextView textView;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            textView = (TextView) findViewById(R.id.textView);
            //为该控件注册菜单项
            registerForContextMenu(textView);
        }
    
        //设置上下文菜单
        @Override
        public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
            menu.add(0, MENU1, 0, "红色");
            menu.add(0, MENU2, 0, "绿色");
            menu.add(0, MENU3, 0, "蓝色");
            menu.setGroupCheckable(0,true,true);
            menu.setHeaderIcon(R.mipmap.ic_launcher);
            menu.setHeaderTitle("选择背景色");
        }
    
        @Override
        public boolean onContextItemSelected(MenuItem item) {
            switch (item.getItemId()) {
                case R.id.red:
                    item.setChecked(true);
                    textView.setBackgroundColor(Color.RED);
                    break;
                case R.id.blue:
                        item.setChecked(true);
                        textView.setBackgroundColor(Color.GREEN);
                        break;
                case R.id.green:
                        item.setChecked(true);
                        textView.setBackgroundColor(Color.BLUE);
                        break;
            }
    
            return true;
        }

--------------------

## 二、使用XML文件定义菜单 ##

### 1.设置选项菜单和子菜单 ###

> 通过在XML文件中设置菜单，在代码中指定其资源文件，并为其重写事件响应方法

*  XML菜单文件

> item元素包含menu元素，menu中又可以包含item元素，表示子菜单，也可以包含group元素，代表一个菜单组，用于指定其全组属性,group中的item元素表示子菜单

*  在代码中指定该菜单资源文件

MenuInflater inflater = new MenuInflater(this);
    inflater.inflate(R.menu.menu_main,menu);

*  在代码中为其定义响应事件即可实现菜单功能

public boolean onOptionsItemSelected(MenuItem item) {
            switch (item.getItemId()) {
                case FONT_10:
                    editText.setTextSize(10);
                    break;
                case FONT_12:
                    editText.setTextSize(12);
                    break;
                case FONT_14:
                    editText.setTextSize(14);
                    break;
                case FONT_16:
                    editText.setTextSize(16);
                    break;
                case FONT_18:
                    editText.setTextSize(18);
                    break;
                case FONT_RED:
                    editText.setTextColor(Color.RED);
                    break;
                case FONT_GREEN:
                    editText.setTextColor(Color.GREEN);
                    break;
                case FONT_BLUE:
                    editText.setTextColor(Color.BLUE);
                    break;
    
                case PLAIN_ITEM:
                    break;
            }
            return true;
        }

### 2.使用XML文件设置上下文菜单 ###

*  XML文件

<?xml version="1.0" encoding="utf-8"?>
    <menu xmlns:android="http://schemas.android.com/apk/res/android">
        
        <group android:checkableBehavior="single">
            
            <item android:id="@+id/red" android:title="@string/red_title" android:alphabeticShortcut="r"/>
            <item android:id="@+id/green" android:title="@string/green_title" android:alphabeticShortcut="g"/>
            <item android:id="@+id/blue" android:title="@string/blue_title" android:alphabeticShortcut="b"/>
        </group>
    </menu>

*  为控件注册上下文菜单

textView = (TextView) findViewById(R.id.textView);
            //为该控件注册菜单项
            registerForContextMenu(textView);

*  为该菜单设置响应事件

public boolean onContextItemSelected(MenuItem item) {
            switch (item.getItemId()) {
                case R.id.red:
                    item.setChecked(true);
                    textView.setBackgroundColor(Color.RED);
                    break;
                case R.id.blue:
                        item.setChecked(true);
                        textView.setBackgroundColor(Color.GREEN);
                        break;
                case R.id.green:
                        item.setChecked(true);
                        textView.setBackgroundColor(Color.BLUE);
                        break;
            }
    
            return true;
        }

--------------------

## 三、为控件设置PopupMenu ##

> PopupMenu可以作为一个控件的弹出式菜单显示在控件旁边
> 
> **实现思路：**  
> 1.调用new PopupMenu(Context context,View view)创建菜单  
> 2.调用MenuInflater的inflate()方法将菜单资源填充到PopupMenu中  
> 3.调用PopupMenu的show()方法显示弹出式菜单

*  菜单XML文件

*  为控件设置点击按钮以显示弹出菜单

public void menu(View view) {
            popupMenu = new PopupMenu(this,view);
    
            getMenuInflater().inflate(R.menu.menu,popupMenu.getMenu());
    
            popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                @Override
                public boolean onMenuItemClick(MenuItem item) {
                    switch (item.getItemId()) {
                        case R.id.exit:
                           popupMenu.dismiss();
                            break;
                        default:
                            Toast.makeText(MainActivity.this, item.getTitle(), Toast.LENGTH_SHORT).show();
                    }
                    return true;
                }
    
            });
            popupMenu.show();
        }