如何按月显示帖子asp.net mvc

Question

基本上是我的post表：

public partial class Mak
{
    public string Name{ get; set; }        
    public DateTime writingDate{ get; set; }
}

我想在我的视图中列出按月份分组的帖子。
我的代码：

@foreach (var tar in Model.Mak.OrderByDescending(x=> x.writingDate.Month).Select(x=> x.writingDate))
{
    <a href="/m/Date?year=@tar.Year&month=@tar.Month">@tar.ToString("MMMM yyyy")</a>

    @foreach (var mak in Model.Mak.Where(x=> x.writingDate==tar))
    {
        <a href="/m/@mak.Name"></a><div> @mak.Name</div>
    }

 }

输出：

   July 2017
Connected //post name

   July  2017
Linq to SQL

   July 2017
OOP

   July 2017
Linq Querys

所需的输出：

   June 2017
xyz //post name
abc    
   July 2017
Connected 
Linq to SQL
OOP
Linq Querys

我应该如何编写这个查询？

Answer 1

你可以试试这样的：

@{
    // gets the records grouped based on Year and Month. 
    // Creates an object of IEnumerable<IGrouping<>> type
    var groupedByMonth = Model.Mak
                        .OrderByDescending(x => x.writingDate)
                        .GroupBy(x => new { x.writingDate.Year, x.writingDate.Month });

    // loop thorugh each group 
    foreach (var group in groupedByMonth)
    {
        // each group will have 2 "Keys" with Month and Year value.
        // or use Url.Action() to form your anchor 
        <a href="/m/Date?year=@group.Key.Year&month=@group.Key.Month">@group.FirstOrDefault().writingDate.ToString("MMMM yyyy")</a> <br>

        // looping through contents of group
        // IGrouping inherits from IEnumerable, so this is possible
        foreach (var mak in group)
        {
            <a href="/m/@mak.Name"><div> @mak.Name</div> </a><br>
        }
    }
}

Answer 2

使用月份和年份按您的集合分组，然后遍历分组的项目。

@{
    var posts = Model.Mak; // Assuming this is the list of posts;
    DateTimeFormatInfo dtfi = new DateTimeFormatInfo();
    var postGrouped = posts.GroupBy(x => new { Month = x.WritingDate.Month,
                                                         Year = x.WritingDate.Year });
}
@foreach (var item in postGrouped)
{
    <a href="@Url.Action("date","m",new { year=item.Key.Year, month=item.Key.Month})">
                        @dtfi.GetAbbreviatedMonthName(item.Key.Month) @item.Key.Year</a>
    foreach (var post in item)
    {
        <div>
            <a href="/m/@(post.Title)">@post.Title</a>
        </div>
    }
}

GetAbbreviatedMonthName 方法接受表示月份的整数并返回字符串名称。

我还建议使用 html 辅助方法来呈现链接的 href 值（使用 Url.Action 或 Html.ActionLink 辅助方法）。在编写 C# 类时，还要考虑遵循 PascalCasing 方法。 （WritingDate 而不是writingDate）