ASP.NET：从数据库中的值生成ListBoxItems

发布于 2024-11-29 01:34:04 字数 951 浏览 1 评论 0原文

我想填充一个列表框，所以我必须定义一个 ListBoxItem 数组。数据存储在数据库中。

这是我原来的方法：

public IEnumerable<String> GiveStudentsNormalAsString(int lesson, int class)
    {
        Lesson l = giveLesson(lesson);
        Class c = GiveClass(l, class);
        return (from s in c.Students
                orderby s.Name, s.FirstName
                select s.Name);
    }

所以“班级”包含学生列表（导航属性）。我想要做的不是返回字符串的 IEnumerable，而是返回 SelectListItems 的 IEnumerable。

我已经开始了：

public IEnumerable<SelectListItem> GiveStudentsNormalAsString(int lesson, int class)
    {
        Lesson l = giveLesson(lesson);
        Class c = GiveClass(l, class);
        return .Select(student => new SelectListItem
        {
            Text = ...
            Value = ...
        };
    }

但是我必须写什么作为文本和值？例如，我希望将学生编号作为值，我该怎么做？

这是我的 edmx： EDMX1

原文

I want to populate a listbox, so I have to define an array of ListBoxItem.
The data is stored in a database.

This is my original method:

public IEnumerable<String> GiveStudentsNormalAsString(int lesson, int class)
    {
        Lesson l = giveLesson(lesson);
        Class c = GiveClass(l, class);
        return (from s in c.Students
                orderby s.Name, s.FirstName
                select s.Name);
    }

So "Class" contains a List of Students (a navigational property).
What I want to do is not returning an IEnumerable of Strings, but an IEnumerable of SelectListItems.

I started already:

public IEnumerable<SelectListItem> GiveStudentsNormalAsString(int lesson, int class)
    {
        Lesson l = giveLesson(lesson);
        Class c = GiveClass(l, class);
        return .Select(student => new SelectListItem
        {
            Text = ...
            Value = ...
        };
    }

But what do I have to write as Text and Value? for example, I want the Student Number act as Value, how can I do that?

Here's my edmx:
EDMX1

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濫情▎り 2024-12-06 01:34:04

您只需在构建 SelectListItem 时引用 student 变量即可：

public IEnumerable<SelectListItem> GiveStudentsNormalAsString(int lesson, int class)
{
    Lesson l = giveLesson(lesson);
    Class c = GiveClass(l, class);
    return c.Students.Select(student => new SelectListItem
    {
        Text = student.Name,
        Value = student.Number.ToString()
    });
}

当然，如果您愿意，也可以使用 LINQ 语法编写它：

public IEnumerable<SelectListItem> GiveStudentsNormalAsString(int lesson, int class)
{
    Lesson l = giveLesson(lesson);
    Class c = GiveClass(l, class);
    return (from student in c.Students
            select new SelectListItem
            {
                Text = student.Name,
                Value = student.Number.ToString()
            });
}

You just refer to the student variable when building the SelectListItem:

public IEnumerable<SelectListItem> GiveStudentsNormalAsString(int lesson, int class)
{
    Lesson l = giveLesson(lesson);
    Class c = GiveClass(l, class);
    return c.Students.Select(student => new SelectListItem
    {
        Text = student.Name,
        Value = student.Number.ToString()
    });
}

Of course it can also be written using the LINQ syntax, if you prefer so:

public IEnumerable<SelectListItem> GiveStudentsNormalAsString(int lesson, int class)
{
    Lesson l = giveLesson(lesson);
    Class c = GiveClass(l, class);
    return (from student in c.Students
            select new SelectListItem
            {
                Text = student.Name,
                Value = student.Number.ToString()
            });
}

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