JavaScript Ajax 设置与获取自定义 Header 完整指南

$.ajax({
  type: "POST",
  url: "Handler1.ashx",
  contentType: "application/x-www-form-urlencoded",
  beforeSend: function (request) {
    request.setRequestHeader("token1", "Chenxizhang");
  },
  success: function (data) {
    //your code
  }
});

$.ajax({
  headers: {
    "testheader": "test"
  },
  type: "POST",
  url: "Handler1.ashx",
  contentType: "application/x-www-form-urlencoded",
  success: function (data) {
    //your code
  }
});

$.ajax({
  type: "POST",
  url: "Handler1.ashx",
  contentType: "application/x-www-form-urlencoded",
  success: function (data) {
    //your code
  },
  complete: function (xhr, data) {
    /* 
      获取相关Http Response header
      getResponseHeader(key)：获取指定头信息
      getAllResponseHeaders()：获取全部可默认可获取的头信息
    */
    var date=xhr.getResponseHeader('Date');// 服务器端时间
    
    //获取服务端自定义的header信息
    var stoken = xhr.getResponseHeader('servertoken');
    
    var list = xhr.getAllResponseHeaders();
    console.log(list);
    /*
    date: Fri, 12 Jul 2019 12:41:00 GMT
    content-encoding: gzip
    server: Microsoft-IIS/10.0
    x-aspnet-version: 4.0.30319
    x-powered-by: ASP.NET
    vary: Accept-Encoding
    content-type: text/plain; charset=utf-8
    servertoken: test1
    cache-control: private
    content-length: 129
    */
    
  }
});

public void ProcessRequest(HttpContext context)
{
  context.Response.AddHeader("Access-Control-Allow-Origin", "*");
  context.Response.AddHeader("Access-Control-Allow-Headers", "*");
  context.Response.AddHeader("Access-Control-Allow-Methods", "*");
  //自定义header信息
  context.Response.AddHeader("servertoken", "test");
  context.Response.AddHeader("Access-Control-Expose-Headers", "servertoken");
  context.Response.ContentType = "text/plain";
  context.Response.Write("Hello World");
}