What should I do if jquery cannot receive data?

Solution to the problem that jquery cannot receive data: 1. Set "contentType:"application/x-www-form-urlencoded""; 2. Just check the post and get statements.

The operating environment of this article: Windows7 system, jquery3.2.1, Dell G3 computer.

What should I do if jquery cannot receive data? jQuery ajax cannot get data from the background?

ajax post data cannot obtain data, pay attention to the setting of content-type and post/get

About jQuery data passing data. There are various data that cannot be obtained online, garbled characters, etc.

Okay, I also encountered it today. I searched all kinds of tangles online. No matter if you look at the garbled code first, you cannot get the data.

Because I have always used jQuery ajax get to pass parameters, the value of contentType has not been set by default.

   1:      var Skip = 49; //Number of skipped row

   2:      var Take = 14; //
   3:      function Load(Skip, Take) {
   4:          $(&#39;#pPostsLoader&#39;).html(&#39;<img src="ProgressBar/ajax-loader.gif">&#39;);
   5:          //send a query to server side to present new content
   6:          $.ajax({
   7:              type: "get",
   8:              url: "AjaxImage.ashx",
   9:              data: { Skip: Skip, Take: Take },
  10:              //contentType: "application/json; charset=utf-8",//(可以)
  11:              //contentType: "text/xml",//(可以)
  12:              //contentType:"application/x-www-form-urlencoded",//(可以)
  13:              //dataType: "string",
  14:              success: function (data) {
  15:                  if (data != "") {
  16:                      $(&#39;.thumb&#39;).append(data);
  17:                  }
  18:                  $(&#39;#pPostsLoader&#39;).empty();
  19:              }
  20:          })
  21:      };

Under chrome, the value of contentType is not set. OK, let’s look at the default situation in jquery:

The default parameters are passed through the url parameter, request Content type: application/x-www-form-urlencoded

General processing file acquisition parameter content:

int Skip = Convert.ToInt32(context.Request["Skip"]); 2: int Take = Convert.ToInt32(context.Request["Take"]);

No pressure, because I have always done this without any problems. Okay, let’s change the content type of the request:

1: //contentType: "application/json; charset=utf-8",//(可以) 2: //contentType: "text/xml",//(可以)

<p>也都可以，参数获取正常。<br></p>

This is what we call the get method. The parameters follow the url and have nothing to do with Content-Type.

可是今天要用post方式了有木有。

1: $.ajax({ 2: type: "post",

<p>chrome下，没有设置contentType的值，来看默认情况：<br></p>

data data is submitted from the form, the requested content type: application/x-www-form-urlencoded,

Okay, by default, it is also possible to obtain parameters by generally processing files.

However, what I initially set was contentType: "application/ json; charset=utf-8", look at the picture:

What is Request Paload???

Debug it, look at our from, there is no Content:

Tested:

   1:              //contentType: "application/json; charset=utf-8",//(不可以)
   2:              //contentType: "text/xml",//(不可以)
   3:              contentType:"application/x-www-form-urlencoded",//(可以)

<p>总结一下吧：本来get/post方式都是知道的，但注意，contentType与传递数据匹配（本文data）。<br></p>

<p> 做过模拟登录、模拟提交数据的同学肯定都很清楚了。<br></p>

Recommended learning: "jquery video tutorial"

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