Select2 不显示选项

Question

I'm currently testing Select2.js in my ASP.NET MVC project.我目前正在我的 ASP.NET MVC 项目中测试 Select2.js。

The first test on a "normal" view just worked fine but now I'm trying to add this to a select box inside a partial view that gets loaded on Ajax Call and then displayed inside a <div> on the normal view page.对“普通”视图的第一个测试运行良好，但现在我尝试将其添加到局部视图内的选择框中，该视图在 Ajax 调用上加载，然后显示在普通视图页面上的<div>内。

The code to generate the dropdown looks like this:生成下拉列表的代码如下所示：

@Html.DropDownList("addRole",
   new SelectList(ViewBag.availableRoles, "Id", "Name"),
   "Rolle auswählen", 
   new { @name="addRole", @class = "form-control" }
)

And on the end of the partial view file I added the following:在局部视图文件的末尾，我添加了以下内容：

$(document).ready(function () {
    //var data = [{ id: 1, text: "Test" }];

    $("#addRole").select2({
        //data: data
    });
});

It looks like it works because of the look of the select box changes but when I try to open it, it just shows nothing.看起来它可以工作，因为选择框的外观发生了变化，但是当我尝试打开它时，它什么也没显示。 Same happens when I uncomment the data variable code above.当我取消注释上面的data变量代码时，也会发生同样的情况。

It just doesn't show anything to me and I don't know why.它只是没有向我显示任何内容，我不知道为什么。

I've already tried to add the JavaScript code to $(document).ajaxComplete or in the success function from the AJAX call but it doesn't change anything.我已经尝试将 JavaScript 代码添加到$(document).ajaxComplete或来自 AJAX 调用的success函数中，但它没有改变任何东西。

Answer 1

I got the answer now.我现在得到了答案。 The problem was not that the select2 element has no items, the problem was the given items did not show up.问题不是 select2 元素没有项目，问题是给定的项目没有显示。 So I thought about why didn´t they show up and found out that I´m really stupid.所以我想为什么他们没有出现，发现我真的很愚蠢。 It did show up, but I can´t see it because of the z-index.它确实出现了，但由于 z-index 我看不到它。 My popup window got a z-index of 20k so the dropdown list was behind the window.我的弹出窗口的 z-index 为 20k，因此下拉列表位于窗口后面。

So to solve this just add:所以要解决这个问题，只需添加：

.select2-dropdown {
    z-index:99999;
}

Or add a dropdownCssClass to the select2 settings with the given z-index like this:或者使用给定的 z-index 将 dropdownCssClass 添加到 select2 设置，如下所示：

.select2-dropdown.increasezindex {
    z-index:99999;
}

JS: JS：

$(document).ready(function () {
    $("#addRole").select2({
        dropdownCssClass:'increasezindex'
    });
});

Answer 2

In my case, I was displaying a select2 on a pop-up element and this causes the dropdown to disappear because it is attached by default to the <body> element.就我而言，我在弹出元素上显示 select2，这会导致下拉菜单消失，因为它默认附加到<body>元素。

Select2 troubleshooting guide highlights a similar issue with Bootstrap modals. Select2 故障排除指南强调了 Bootstrap 模态的类似问题。

To overcome this problem I had to use the dropdown placement option provided,为了克服这个问题，我不得不使用提供的下拉位置选项，

let $select = $('select'), 
  $parent = $select.parent();

$select.select2({
  dropdownParent: $parent
});

Select2 不显示选项

问题描述

2 个解决方案

解决方案1
2 2017-10-25 08:55:34

解决方案2
1 2021-03-31 15:07:23

Select2 不显示选项

问题描述

2 个解决方案

解决方案1 2 2017-10-25 08:55:34

解决方案2 1 2021-03-31 15:07:23

解决方案1
2 2017-10-25 08:55:34

解决方案2
1 2021-03-31 15:07:23