Menu 菜单的 学习

package com.crazyit.ui.menudemo;

import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.EditText;
import android.widget.Toast;

/**
 * Menu 菜单的 学习
 */
public class MainActivity extends AppCompatActivity {
    EditText editText;

    //定义字体大小菜单项的标识
    public static final int FONT_10 = 0x111;
    public static final int FONT_12 = 0x112;
    public static final int FONT_14 = 0x113;
    public static final int FONT_16 = 0x114;
    public static final int FONT_18 = 0x115;

    //定义普通菜单项的标识
    public static final int PLAIN_ITEM = 0x11b;

    //定义字体颜色菜单项的标识
    public static final int FONT_RED = 0x116;
    public static final int FONT_BLUE = 0x117;
    public static final int FONT_GREEN = 0x118;


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

        editText = (EditText) findViewById(R.id.editText);
    }

    /**
     * 当用户点击菜单键的 触发该方法
     *
     * @param menu
     * @return
     */
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //-----向menu中 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.font);

        //设置菜单头的图标
        fontmenu.setHeaderIcon(R.drawable.font);

        //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, "普通菜单项");

        SubMenu colorMenu = menu.addSubMenu("字体颜色");
        colorMenu.setIcon(R.drawable.color);
        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);
    }

    //选项菜单的菜单项被选中后的回调方法

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        //判断单机的是哪一个菜单项,并有针对性的做出反应
        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_BLUE:
                editText.setTextColor(Color.BLUE);
                break;
             case FONT_GREEN:
                editText.setTextColor(Color.GREEN);
                break;
            case PLAIN_ITEM:
                Toast.makeText(this, "您单击了普通菜单项", Toast.LENGTH_SHORT).show();
            break;

        }
        return true;
    }
}