Android开发实现SubMenu选项菜单和子菜单示例

public class MainActivity extends AppCompatActivity {
  //定义 “字体大小” 菜单项的标识
  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;
  //定义“普通菜单项” 的标识
  final int PLAIN_ITEM = 0x11b;
  //定义“字体颜色”的菜单项的标识
  final int FONT_RED = 0x116;
  final int FONT_BLUE = 0x117;
  final int FONT_GREEN = 0x118;
  private EditText editText;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    editText = (EditText) findViewById(R.id.txt);
  }
  //当用户点击按钮键时 触发该方法
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    //添加字体大小的子菜单
    SubMenu fontMenu = menu.addSubMenu("字体大小");
    //设置菜单图标
    fontMenu.setIcon(R.drawable.seek02);
    //设置菜单头的图标
    fontMenu.setHeaderIcon(R.drawable.seek03);
    //设置菜单头的标题
    fontMenu.setHeaderTitle("选择字体大小");
    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");
    //向Menu中添加普通菜单项
    menu.add(0, PLAIN_ITEM, 0, "普通菜单选项");
    //向Menu中添加"字体颜色"的子菜单
    SubMenu colorMenu = menu.addSubMenu("字体颜色");
    colorMenu.setIcon(R.drawable.find1);
    //设置菜单头图标
    colorMenu.setHeaderIcon(R.drawable.find);
    //设置菜单头标题
    colorMenu.setHeaderTitle("选择文字颜色");
    colorMenu.add(0, FONT_RED, 0, "红色");
    colorMenu.add(0, FONT_GREEN, 0, "绿色");
    colorMenu.add(0, FONT_BLUE, 0, "蓝色");
    return super.onCreateOptionsMenu(menu);
  }
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    //判断单机的是那个菜单项
    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:
        Toast.makeText(MainActivity.this,"you click menu",Toast.LENGTH_SHORT).show();
        break;
    }
    return true;
  }
}

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context=".MainActivity">
  <EditText
    android:id="@+id/txt"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="用于测试的内容"/>
</android.support.constraint.ConstraintLayout>