MVC 与 jQuery Ajax 调用无法正确绑定空数组/可枚举

发布于 2024-12-14 15:48:27 字数 732 浏览 2 评论 0原文

我有一个 jQuery ajax 调用，其中我试图发送可以从复选框表中选择的用户的 int ID。

我遇到的问题是没有选择任何用户。我希望得到一个空数组，但实际上我收到一个 length = 1 的数组，其中包含 userId 0（即未分配的 int 值）。

以下代码片段重现了问题，

$('#test').click(function () {
    var numbers = $('.noElements').map(function () {
        // (selector does not match any elements, to demonstrate)
        return 1;
    }).get();

    $.ajax({
        url: '/MyController/Test',
        type: "GET",
        data: { numbers: numbers, count: numbers.length }
    });
});


public ActionResult Test(IEnumerable<int> numbers, int count)
{
    Assert(numbers.Count() == count);
    return null;
}

断言失败，因为 numbers 是 List; { 0 }。为什么绑定会发生这样的情况？

原文

I have a jQuery ajax call in which I am trying to send the int IDs of users which can be selected from a table of checkboxes.

I am having a problem with the case that no users are selected. I would expect an empty array but in fact I receive an array of length = 1, containing userId 0 (i.e. an unassigned int value).

The following snippet reproduces the problem

$('#test').click(function () {
    var numbers = $('.noElements').map(function () {
        // (selector does not match any elements, to demonstrate)
        return 1;
    }).get();

    $.ajax({
        url: '/MyController/Test',
        type: "GET",
        data: { numbers: numbers, count: numbers.length }
    });
});


public ActionResult Test(IEnumerable<int> numbers, int count)
{
    Assert(numbers.Count() == count);
    return null;
}

The Assert fails because numbers is List<int> { 0 }. Why is the binding happening like this?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

梦忆晨望 2024-12-21 15:48:27

我相信默认模型绑定器会将 jQuery AJAX 调用传递给它的空字符串转换为一个整数数组，该数组包含单个元素，该元素包含整数的默认值 (0)。如果你做了这样的事情，你的代码就会工作 -

$('#test').click(function () {
    var numbers = $('.noElements').map(function () {
        return 1;
    });
    if (numbers.length == 0) {
        numbers = null;
        count = 0;
    }
    else count = numbers.length;

    $.ajax({
        url: '/Home/Test',
        type: "GET",
        data: { numbers: numbers, count: count }
    });
});

请参阅此问题以获取更多信息和替代解决方案 - 如何发布（整数）空数组（jQuery -> MVC 3）

I believe that the default model binder will convert the empty string that is passed to it by the jQuery AJAX call into a integer array that contains a single element containing the default value of an integer (0). Your code would work if you did something like this-

$('#test').click(function () {
    var numbers = $('.noElements').map(function () {
        return 1;
    });
    if (numbers.length == 0) {
        numbers = null;
        count = 0;
    }
    else count = numbers.length;

    $.ajax({
        url: '/Home/Test',
        type: "GET",
        data: { numbers: numbers, count: count }
    });
});

See this question for further info and alternate solutions - How to post an empty array (of ints) (jQuery -> MVC 3)

回复收藏 0 原文

~没有更多了~