有一个Jquery选择器可以工作，但在$ .post中不起作用

Question

I have this Jquery line which finds the cell I would like to input data into, This works when I use it outside of my $.post function (below), but not inside my $.post

$(this).parent().parent().find(".total_item_price").html("new text");

But when I use the above line in the below example, It does not work. It doesn't update the text in the required field.

$.post(url, { "params": value}, function(data) {

          // This is where I am having a problem
          // also tried .text and .val
          $(this).parent().parent().find(".total_item_price").html(data.total_price_item);

          alert(data.total_price_item); // This outputs my data
       }, "JSON"); 

I basically want to put my returned (data) into the cell of the table. I don't think that my table structure is the issue, but I can post it if needed.

I should add, that I have to find the parents and field, because each post function will output into a different cell, so its relative to where the user clicked.

Whats going wrong in this code?

Answer 1

Because this inside your load callback is not equal to this outside of your load callback. They have different scopes.

Before you call the post, cache the this from the other scope into a variable:

var scope = this;

And then in your callback you can reference the other this as scope :

$(scope).parent().parent().find(".total_item_price").html(data.total_price_item);

Answer 2

In $.post this will not point to the same element which you are thinking. Please use the actual selector to make it work.

Answer 3

因为你的函数中的“this”是对函数的引用，而不是对节点的引用！

Answer 4

($this) is not what you think it is! this is always the owner of the function being executed, which in the $.post is the callback function.

Answer 5

you can do it like this,

  var a= $(this);
  $.post(url, { "params": value}, function(data) {

          // This is where I am having a problem
          // also tried .text and .val
          a.parent().parent().find(".total_item_price").html(data.total_price_item);

          alert(data.total_price_item); // This outputs my data
       }, "JSON"); 

Answer 6

$(this) will not work there. As it is in the scope of the callback function, not the click event.

Assign $(this) to a variable outside of the post (inside the click event handler) and then use that inside the post callback.

  var that = $(this);
  $.post(url, { "params": value}, function(data) {
      that.parent().parent().find(".total_item_price").html(data.total_price_item);
      alert(data.total_price_item); // This outputs my data
  }, "JSON");