使用 Dapper 调用自定义构造函数? [英] Call custom constructor with Dapper?

问题描述

我正在尝试使用 Dapper 与 ASP.NET SQL Membership Provider 表进行交互.我包装了 SqlMembershipProvider 类，并添加了一个额外的方法，根据与我拥有的一些自定义表相关的特定条件来获取 MembershipUsers.

I'm trying to use Dapper to interface with the ASP.NET SQL Membership Provider tables. I wrapped the SqlMembershipProvider class and added an additional method to get me the MembershipUsers given a certain criteria relating to some custom tables I have.

当使用 Dapper 查询数据时，似乎 Dapper 首先使用无参数构造函数实例化类，然后将返回的列映射"到对象的属性中.

When querying the data with Dapper, it appears that Dapper first instantiates the class with a parameter-less constructor, and then "maps" the returned columns into the properties on the object.

但是，MembershipUser 类的 UserName 属性没有设置器.从 Dapper SqlMapper.cs 的 1417 行左右来看，方法 GetSettableProps() 只获取可设置的属性.

However, the UserName property on the MembershipUser class has a no setter. Judging from around line 1417 in the Dapper SqlMapper.cs, the method GetSettableProps() only gets settable properties.

我尝试执行 MultiMap 查询来调用构造函数，但问题是传递给查询的对象已经缺少用户名.

I tried to do a MultiMap query to invoke the constructor, but the problem with that is the objects passed into the query are already missing the UserName.

我猜我可以修改 GetSettableProps() 方法，但我不确定这是否有效，或者它是否会影响我现有的代码.

I'm guessing I could modify the GetSettableProps() method, but I'm not sure if that will work, or if it will affect my existing code.

我是否可以调用 MembershipUser 类具有的自定义构造函数?

或者我可以对 Dapper 做出合理的改变来支持我的情况吗?

** 更新 **

Marc 使用非通用/动态 Query() 方法的回答是正确的，但对于后代，这是我在 Dapper 中所指的方法:

Marc's answer to use the non-generic/dynamic Query() method was correct, but for posterity, this is the method I was referring to inside Dapper:

static List<PropInfo> GetSettableProps(Type t)
{
    return t
          .GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
          .Select(p => new PropInfo
          {
              Name = p.Name,
              Setter = p.DeclaringType == t ? p.GetSetMethod(true) : p.DeclaringType.GetProperty(p.Name).GetSetMethod(true),
              Type = p.PropertyType
          })
          .Where(info => info.Setter != null)
          .ToList();  
}

推荐答案

我会在这里使用非通用查询 API...

I would use the non-generic Query API here...

 return connection.Query(sql, args).Select(row =>
     new AnyType((string)row.Foo, (int)row.Bar) {
         Other = (float)row.Other }).ToList();

使用它，您可以使用非默认构造函数和属性赋值，无需任何更改，将动态"用作中间步骤.

Using this you can use both non-default constructors and property assignments, without any changes, by using "dynamic" as an intermediate step.

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