我有两个相似的ViewModel,并且我需要将一个投向另一个。
这是第一个:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace TestInheritance.Models
{
public class ShowMatrixQuestionViewModel : ShowQuestionViewModel
{
public Dictionary<MatrixRows, List<MatrixColumns>> columnrow;
public List<MatrixColumns> columns;
public List<MatrixRows> rows;
public ShowMatrixQuestionViewModel()
{
columns = new List<MatrixColumns>();
rows = new List<MatrixRows>();
columnrow = new Dictionary<MatrixRows, List<MatrixColumns>>();
}
}
public class MatrixColumns
{
public int Column_ID { get; set; }
public int Column_Number { get; set; }
public String Column_Description { get; set; }
public Boolean IsAnswer { get; set; }
public int Procent { get; set; }
}
public class MatrixRows
{
public bool Delete { get; set; }
public int Row_Id { get; set; }
public String Row_Number { get; set; }
public String Row_Description { get; set; }
}
}
第二个看起来像这样:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace TestInheritance.Models.ViewModels.New
{
public class ShowMatrixProcentViewModel : ShowMatrixQuestionViewModel
{
// Dette er for at vi kan bruge DisplayTemplates
public ShowMatrixProcentViewModel()
: base()
{
}
}
}
当我尝试将ShowMatrixQuestionViewModel投射到ShowMatrixProcentViewModel时,我收到InvalidCastException:
MatrixColumns mc = new MatrixColumns()
{
Column_Description = "Hej",
Column_ID = 1,
Column_Number = 1,
IsAnswer = false
};
MatrixColumns mc2 = new MatrixColumns()
{
Column_Description = "Med",
Column_ID = 1,
Column_Number = 1,
IsAnswer = false
};
MatrixRows mr = new MatrixRows()
{
Row_Description = "2005",
Row_Id = 1,
Row_Number = "1"
};
MatrixRows mr2 = new MatrixRows()
{
Row_Description = "2008",
Row_Id = 1,
Row_Number = "2"
};
List<MatrixColumns> matrixcolumns = new List<MatrixColumns>();
matrixcolumns.Add(mc);
matrixcolumns.Add(mc2);
List<MatrixRows> matrixrows = new List<MatrixRows>();
matrixrows.Add(mr);
matrixrows.Add(mr2);
ShowMatrixQuestionViewModel avm = new ShowMatrixQuestionViewModel()
{
IsAnswered = true,
Question_ID = 1,
Question_Number = "1",
Question_Type = "hej",
Question_Wording = "spørgsmål1",
Visible = true,
columns = matrixcolumns,
rows = matrixrows
};
ShowMatrixProcentViewModel sm = (ShowMatrixProcentViewModel)avm;
return View(avm);
异常说明:
System.InvalidCastException:无法将类型为“ TestInheritance.Models.ShowMatrixQuestionViewModel”的对象转换为类型为“ TestInheritance.Models.ViewModels.New.ShowMatrixProcentViewModel”的对象。
在投放之前,我需要在ShowMatrixProcentViewModel中初始化一些东西吗?
提前致谢
最佳答案
由于ShowMatrixProcentViewModel继承自ShowMatrixQuestionViewModel,因此您不能仅从ShowMatrixQuestionViewModel投射到ShowMatrixProcentViewModel。这是基本的面向对象。您只能在子类>超级类方向上进行投射。原因是ShowMatrixQuestionViewModel不包含ShowMatrixProcentViewModel所包含的所有内容。
您可以使用AutoMapper之类的东西,但是您可能应该看一下您的设计/体系结构,因为这样的东西表明结构不好。
关于c# - 如何将ViewModel强制转换为另一个ViewModel?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/7712519/