Question

我正在使用惰性加载来获取我所有的相关数据，并将json返回到我的API。但是我似乎无法获取所有相关数据。

也不知道如何正确使用include语法。

public class Recipe
{
    public int Id { get; set; }
    public string RecipeDescription { get; set; }
    public int? HowManyPersons { get; set; }
    public int? TimeCreated { get; set; }
    public virtual ICollection<IngredientQuantity> IngredientQuantities { get; set;}
    public int RecipeTypeId { get; set; }
    public virtual RecipeType RecipeType { get; set; }
    public string PreparationMethods { get; set; }
}


 public class IngredientQuantity
{
    public int id { get; set; }
    public int IngredientId { get; set; }
    [ForeignKey("IngredientId")]
    public virtual Ingredient Ingredient { get; set; }
    public string Amount { get; set; }
    public int QuantityTypeId { get; set; }
    [ForeignKey("QuantityTypeId")]
    public virtual QuantityType QuantityType { get; set; }
    public int RecipeId { get; set; }
    [ForeignKey("RecipeId")]
    public virtual Recipe Recipe { get; set; }
}

public class Ingredient
{
    public int Id { get; set; }
    public string IngredientDecsription { get; set; }

}

public async Task<IEnumerable<Recipe>> GetAll()
{
    try
    {
        var recipe = await context.Recipe
            .Include(r => r.RecipeType)
            .Include(r => r.IngredientQuantities)
            .ThenInclude(iq => iq.Ingredient)

            .ToListAsync();

        return recipe;
    }
    catch(Exception ex)
    {
        return null;
    }
}

这是我的json输出：

{“ results”：[{“ ingredientQuantities”：[{“ ingredient”：{“ id”：1，“ ingredientDecsription”：“ Spinazie”}，“ quantityType”：{“ id”：1，“ quantityTypeDescription” ：“处理”}

Answer 1

您可以将Json.NET配置为忽略它在对象图中找到的循环。尝试在启动时添加以下代码：

public void ConfigureServices(IServiceCollection services)
{
  ...

  services.AddMvc()
    .AddJsonOptions(
        options => options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
    );

  ...
}

请参阅Related data and serialization

为什么无法获取与我的模型有关的所有数据？

1 个答案: