electron程序，如何添加系统顶部菜单并定义相关菜单事件？

// const {Menu} = require('electron')
function createWindow () {
  Menu.setApplicationMenu(null)
  //...
}

app.on('ready', () => {
  Menu.setApplicationMenu(Menu.buildFromTemplate([]))
})

const { Menu,dialog} = require('electron')
app.on('ready', () => {
  let template = [{
    label: '测试菜单',
    submenu: [{
      label: '菜单role',
      accelerator: 'CmdOrCtrl+1',
      role: 'selectall'
    }, {
      type: 'separator'
    }, {
      label: '菜单click',
      accelerator: 'CmdOrCtrl+2',
      click: (item, focusedWindow) => {
        dialog.showMessageBox({
          title: "帮助",//信息提示框标题
          message: "alert",//信息提示框内容
          buttons: ["ok"],//下方显示的按钮
          noLink:true, //win下的样式
          type: "info",//图标类型
        }, function (index) {
          console.log(index);
        });
      }
    }]
  }];
  const menu = Menu.buildFromTemplate(template)
  Menu.setApplicationMenu(menu)
})