按首字母分组收集物品

Question

我有一系列品牌，它们返回一个IEnumerable，并按照第一个字母对品牌进行分组。

@{
    var brands = Service.GetBrands();

    <div class="list">
    @foreach (var brand in brands.GroupBy(x => x.Substring(0, 1).ToUpper(), (alphabet, subList) => new { Alphabet = alphabet, SubList = subList.OrderBy(x => x).ToList() }).OrderBy(x => x.Alphabet))
    {
         <h4 class="letter">@brand.Alphabet</h4>
         <div class="row">
            @foreach (var item in brand.SubList)
            {
                <div class="brand col-md-3">
                    <div class="brand__title">@item</div>
                </div>
            }
            </div>
    }
    </div>
}

呈现以下内容：

但是如果没有品牌以例如字母B，我怎么能总是呈现字母A-Z？我可以以某种方式加入一个带有字母属性的数组吗？

char[] letterArray = "ABCDEFGHIJKLMNOPQRSTUVWXYZÆØÅ".ToCharArray();

此外，我可以将任何品牌以＆＃34; 0-9＆＃34; -group中的数字开头？

Answer 1

这样的事情怎么样？

char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray();
var brands = Service.GetBrands();
var numberBrands = brands.Where(x => Char.IsDigit(x.First()));

<h4 class="letter">0-9<h4>  
    <div class="row">
        @foreach(var brand in numberBrands){
            <div class="brand col-md-3">
                <div class="brand__title">@brand</div>
            </div>
        }
    </div>

foreach(var letter in alphabet){
    var subBrands = brands.Where(x => 
    x.StartsWith(letter.ToString(), StringComparison.OrdinalIgnoreCase))
    .OrderBy(x => x);

    <h4 class="letter">@letter<h4>  
    <div class="row">
        @foreach(var brand in subBrands){
            <div class="brand col-md-3">
                <div class="brand__title">@brand</div>
            </div>
        }

    </div>
}