Question

我有一个具有以下型号的WebAPI：

public class Dog
{
    public string name { get; set; }
    public string breed { get; set; }
    public string size { get; set; }
    public CoatType coatType { get; set; }

    private List<Dog> dogs;
}

public enum CoatType 
{ 
    Long, 
    Short, 
    Curly 
};

我的存储库看起来像这样：

public class AnimalRepository
{
    private const string CacheKey = "AnimalStore";

    public AnimalRepository()
    {
        var context = HttpContext.Current;  

        if (context != null)
        {
            if (context.Cache[CacheKey] == null)
            {
                var contacts = new Dog[]
                {
                    new Dog { name = "Lassie", breed = "Collie", size = "Medium", coatType = CoatType.Long },
                    new Dog { name = "Fido", breed = "Labrador", size = "Large" , coatType = CoatType.Short},
                };

                context.Cache[CacheKey] = contacts;
            }
        }
    }

    public Dog[] GetAllAnimals()
    {
        var context = HttpContext.Current;

        if (context != null)
        {
            return (Dog[])context.Cache[CacheKey];
        }

        return new Dog[]
        {
            new Dog
            {
                name = "",
                breed = "Placeholder",
                size = "Placeholder",
                coatType = CoatType.Curly
            }
        };
    }

    public bool SaveAnimal(Dog animal)
    {
        var context = HttpContext.Current;

        if (context != null)
        {
            try
            {
                var currentData = ((Dog[])context.Cache[CacheKey]).ToList();

                bool nameExists = false;

                if (nameExists != true)
                {
                    currentData.Add(animal);
                    context.Cache[CacheKey] = currentData.ToArray();

                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return false;
            }
        }

        return false;
    }
}

我的控制器看起来像这样：

public class AnimalController : ApiController
{
    private AnimalRepository repository;

    public AnimalController()
    {
        this.repository = new AnimalRepository();
    }

    public Dog[] Get()
    {
        return this.repository.GetAllAnimals();
    }

    public HttpResponseMessage Post(Dog animal)
    {
        this.repository.SaveAnimal(animal);
        var response = Request.CreateResponse<Dog>(System.Net.HttpStatusCode.Created, animal);

        return response;
    }

我的Index.cshtml看起来像这样：

<header>
<div class="content-wrapper">
    <div class="float-left">
        <p class="site-title">
            <a href="~/">Field<b>Connect</b></a></p>
    </div>
</div>
</header>
<div id="body">
<ul id="animals"></ul>
<form id="saveForm" method="post">
<h3>New Dog</h3>
    <p>
        <label for="name">Name:</label>
        <input type="text" name="name" />
    </p>
    <p>
        <label for="breed">Breed:</label>
        <input type="text" name="breed" />
    </p>
   <p>
        <label for="size">Size:</label>
        <input type="text" name="size" />
    </p>
   <p>
        <label for="coatType">Coat Type:</label>
        <select name="coatType">
            <option value="Long">Long Hair</option>
            <option value="Short">Short Hair</option>
            <option value="Curly">Curly Hair</option>
        </select>
    </p>
    <input type="button" id="saveAnimal" value="Save" />
</form>
</div>

@section scripts{
<script type="text/javascript">
$(function () {
    $.getJSON('/api/animal', function (contactsJsonPayload) {
        $(contactsJsonPayload).each(function (i, item) {
            $('#animals').append('<li>' + item.name + '</li>');
        });
    });
});

$('#saveAnimal').click(function () {
    $.post("api/animal",
          $("#saveForm").serialize(),
          function (value) {
              $('#animals').append('<li>' + value.name + '</li>');
          },
          "json"
    );
});
</script>
}

所有这一切都很好。我会在我的网页上显示属于定义集合的两只狗。然而，我想要做的是在我将一只新狗保存到我要检查的集合之前，看看该狗目前是否存在于该集合中。所以我开始在代码行之后的AnimalRepository.cs中实现一个forach循环：bool nameExists = false;代码行。

// Check to see if the name of the animal already exists
for (int i = 0; i < currentData.Count; i++)
{
   foreach (var item in currentData[i])
   {
       if (item.Equals(currentData[i].name))
       {
           nameExists = true;
       }
   }
}

但是当我构建时，我得到一个错误，我无法遍历此集合，除非我实现IEnumerable，所以我这样做了。我添加：IEnumerable到我的类继承接口，我将以下代码添加到我的Dog类，在下面完成....

 public class Dog : IEnumerable<Dog>
{
    public string name { get; set; }
    public string breed { get; set; }
    public string size { get; set; }
    public CoatType coatType { get; set; }

    private List<Dog> dogs;

    public IEnumerator<Dog> GetEnumerator()
    {
        if (dogs != null)
        {
            foreach (Dog dog in dogs)
            {
                if (dog == null)
                {
                    break;
                }

                yield return dog;
            }
        }
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        // Lets call the generic version here
        return this.GetEnumerator();
    }
}

public enum CoatType 
{ 
    Long, 
    Short, 
    Curly 
};

但现在当我运行代码时，我看到'未定义'，而不是在页面顶部看到狗的名字。我尝试返回类型字符串的IEnumerable而不是Dog但这没有帮助。我有什么想法可以解决这个问题吗？

Answer 1

for (int i = 0; i < currentData.Count; i++)
{
    foreach (var item in currentData[i])
    {

这些是嵌套循环 - 你确定要第二个吗？ currentData[i]应该是Dog Name，您可以直接查看。令人困惑的部分原因是您的Dog类本身有一个Dogs列表 - 这几乎肯定不是您想要的。

使用唯一键实现Web API

1 个答案: