我有一个网络应用程序,根据当前登录的用户进行标记。我想将页面的图标更改为私有标签的标志,但我无法找到如何做到这一点的任何代码或任何示例。以前有人成功做到过吗?

我想象在一个文件夹中有12个图标,使用哪个favicon.ico文件的引用是与HTML页面一起动态生成的。想法吗?


当前回答

下面是一个片段,使favicon成为一个表情符号或文本。当我在stackoverflow时,它在控制台工作。

function changeFavicon(text) {
  const canvas = document.createElement('canvas');
  canvas.height = 64;
  canvas.width = 64;
  const ctx = canvas.getContext('2d');
  ctx.font = '64px serif';
  ctx.fillText(text, 0, 64);

  const link = document.createElement('link');
  const oldLinks = document.querySelectorAll('link[rel="shortcut icon"]');
  oldLinks.forEach(e => e.parentNode.removeChild(e));
  link.id = 'dynamic-favicon';
  link.rel = 'shortcut icon';
  link.href = canvas.toDataURL();
  document.head.appendChild(link);
}

changeFavicon('❤️');

其他回答

下面是一些可以在Firefox, Opera和Chrome上运行的代码(不同于这里发布的其他答案)。下面是一个在IE11中也能运行的不同代码演示。下面的示例可能无法在Safari或Internet Explorer中运行。

/*!
 * Dynamically changing favicons with JavaScript
 * Works in all A-grade browsers except Safari and Internet Explorer
 * Demo: http://mathiasbynens.be/demo/dynamic-favicons
 */

// HTML5™, baby! http://mathiasbynens.be/notes/document-head
document.head = document.head || document.getElementsByTagName('head')[0];

function changeFavicon(src) {
 var link = document.createElement('link'),
     oldLink = document.getElementById('dynamic-favicon');
 link.id = 'dynamic-favicon';
 link.rel = 'shortcut icon';
 link.href = src;
 if (oldLink) {
  document.head.removeChild(oldLink);
 }
 document.head.appendChild(link);
}

然后你可以这样使用它:

var btn = document.getElementsByTagName('button')[0];
btn.onclick = function() {
 changeFavicon('http://www.google.com/favicon.ico');
};

叉子或查看演示。

或者如果你想要一个表情符号:)

var canvas = document.createElement("canvas");
canvas.height = 64;
canvas.width = 64;

var ctx = canvas.getContext("2d");
ctx.font = "64px serif";
ctx.fillText("☠️", 0, 64); 

$("link[rel*='icon']").prop("href", canvas.toDataURL());

道具https://koddsson.com/posts/emoji-favicon/

下面是我用来为Opera、Firefox和Chrome添加动态图标支持的一些代码。不过我无法让IE或Safari正常工作。基本上Chrome允许动态favicons,但只有当页面的位置(或iframe等)发生变化时才会更新它们:

var IE = navigator.userAgent.indexOf("MSIE")!=-1
var favicon = {
    change: function(iconURL) {
        if (arguments.length == 2) {
            document.title = optionalDocTitle}
        this.addLink(iconURL, "icon")
        this.addLink(iconURL, "shortcut icon")

        // Google Chrome HACK - whenever an IFrame changes location 
        // (even to about:blank), it updates the favicon for some reason
        // It doesn't work on Safari at all though :-(
        if (!IE) { // Disable the IE "click" sound
            if (!window.__IFrame) {
                __IFrame = document.createElement('iframe')
                var s = __IFrame.style
                s.height = s.width = s.left = s.top = s.border = 0
                s.position = 'absolute'
                s.visibility = 'hidden'
                document.body.appendChild(__IFrame)}
            __IFrame.src = 'about:blank'}},

    addLink: function(iconURL, relValue) {
        var link = document.createElement("link")
        link.type = "image/x-icon"
        link.rel = relValue
        link.href = iconURL
        this.removeLinkIfExists(relValue)
        this.docHead.appendChild(link)},

    removeLinkIfExists: function(relValue) {
        var links = this.docHead.getElementsByTagName("link");
        for (var i=0; i<links.length; i++) {
            var link = links[i]
            if (link.type == "image/x-icon" && link.rel == relValue) {
                this.docHead.removeChild(link)
                return}}}, // Assuming only one match at most.

    docHead: document.getElementsByTagName("head")[0]}

要更改favicon,只需访问favicon。更改("ICON URL")使用上述。

(我基于http://softwareas.com/dynamic-favicons的代码。)

一个更现代的方法:

const changeFavicon = link => {
  let $favicon = document.querySelector('link[rel="icon"]')
  // If a <link rel="icon"> element already exists,
  // change its href to the given link.
  if ($favicon !== null) {
    $favicon.href = link
  // Otherwise, create a new element and append it to <head>.
  } else {
    $favicon = document.createElement("link")
    $favicon.rel = "icon"
    $favicon.href = link
    document.head.appendChild($favicon)
  }
}

然后你可以这样使用它:

changeFavicon("http://www.stackoverflow.com/favicon.ico")

我会使用Greg的方法,为favicon.ico创建一个自定义处理程序 下面是一个(简化的)处理程序:

using System;
using System.IO;
using System.Web;

namespace FaviconOverrider
{
    public class IcoHandler : IHttpHandler
    {
    public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "image/x-icon";
        byte[] imageData = imageToByteArray(context.Server.MapPath("/ear.ico"));
        context.Response.BinaryWrite(imageData);
    }

    public bool IsReusable
    {
        get { return true; }
    }

    public byte[] imageToByteArray(string imagePath)
    {
        byte[] imageByteArray;
        using (FileStream fs = new FileStream(imagePath, FileMode.Open, FileAccess.Read))
        {
        imageByteArray = new byte[fs.Length];
        fs.Read(imageByteArray, 0, imageByteArray.Length);
        }

        return imageByteArray;
    }
    }
}

然后你可以在IIS6的web配置的httpHandlers部分使用该处理程序,或者在IIS7中使用' handler Mappings'特性。