我一直在开发一个简单的 Chrome 扩展程序，上下文菜单显示正常，但无法打开弹出窗口。我试图让它根据选择区分操作。

更新

经过几个小时的折腾，我想我已经接近目标了，但现在我收到“无法读取未定义的属性‘linkUrl’”的提示，我不知道它来自哪里。

function getEmail(info,tab) {
    chrome.windows.create({
        url: "https://mail.google.com/mail/?ui=2&view=cm&fs=1&tf=1&shva=1&to="+info.linkUrl.substr(7), 
        width:640,
        height:700,
        focused:true,
        type:"popup",
    })
}

function sendEmail(info,tab) {
    chrome.windows.create({
        url: "https://mail.google.com/mail/?ui=2&view=cm&fs=1&tf=1&shva=1&to=" +info.selectionText,
        width:640,
        height:700,
        focused:true,
        type:"popup",
    })
}

chrome.contextMenus.create({
    title: "Send a New Email",
    contexts:["link", "selection"],
    onclick: checkType(),
});

function checkType(info,tab) {
    if (typeof info.linkUrl === $('a[href^="mailto:"]')) {
        console.log("This should print first");
        // getEmail();
    }
    else { 
        console.log("This should print");
        // sendEmail();
    }
}

manifest.json

{
   "background": {
      "scripts": [ "background.js" ]
   },

   "description": "Creates a context menu option which copies the selected address into a new Gmail compose window.",

   "manifest_version": 2,
   "name": "New Gmail Window",
   "permissions": [ "tabs", "contextMenus" ],
   "version": "0.1"
}