C# 返回类型'；System.String'；不支持。参数名称：表达式MVC枚举

我正在尝试从Asp.net MVC中的枚举创建下拉列表。用下面的代码，我得到了上面的错误

以下是代码：

<div class="col-md-10">
            @Html.EnumDropDownListFor(model => model.SenderType, null, htmlAttributes: new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model.SenderType, "", new { @class = "text-danger" })
        </div>

型号：

public enum SenderType
{
    Transactional,
    Promotional
}
public class SenderModel
{
    [Key]
    public int SenderId { get; set; }

    [Display(Name = "Sender Name")]
    public string SenderName { get; set; }
    [Display(Name = "Sender Type")]
    public string SenderType { get; set; }
    [Display(Name = "Sender Purpose")]
    public string SenderPurpose { get; set;}

    public int UserId { get; set; }
    public virtual ApplicationUser User { get; set; }
}

---

我已经发布了我的代码。感谢您的帮助

，因为您的模型中有

SenderType

属性作为字符串类型，该属性已在razor中使用，

EnumDropDownList for

不支持该属性

EnumDropDownListFor

expect enum type属性，因此您的

SenderType

属性应为

SenderType

enum类型。因此，您的模型应该是：

public class SenderModel
{
    [Key]
    public int SenderId { get; set; }

    [Display(Name = "Sender Name")]
    public string SenderName { get; set; }

    [Display(Name = "Sender Type")]
    public SenderType SenderType { get; set; } // SenderType should be of type enum SenderType
    [Display(Name = "Sender Purpose")]
    public string SenderPurpose { get; set;}

    public int UserId { get; set; }
    public virtual ApplicationUser User { get; set; }
}

---

什么是model.SenderType？您可以在模型中将“publicstringsenderType{get；set；}”视为EnumDropDownListFor不支持的字符串类型

public class SenderModel
{
    [Key]
    public int SenderId { get; set; }

    [Display(Name = "Sender Name")]
    public string SenderName { get; set; }

    [Display(Name = "Sender Type")]
    public SenderType SenderType { get; set; } // SenderType should be of type enum SenderType
    [Display(Name = "Sender Purpose")]
    public string SenderPurpose { get; set;}

    public int UserId { get; set; }
    public virtual ApplicationUser User { get; set; }
}