How to cast data to nested class in linq-CodePudding

I am using linq to cast data row to MapValueFields class, but row values are strings, so it trigger casting error, any help is appreciated.

Inside class

 public partial class MapValueFields
  {
    public GrandTotal Amount { get; set; }
    ...
  }

 public partial class GrandTotal
  {
    public string DoubleValue { get; set; }
  }

I tried this

 List<MapValueFields> items = viewLaundry.ToTable().Rows.Cast<DataRow>().Select(t => new MapValueFields()
 {
   Amount = t.Field<GrandTotal>("Total Amount"), // here is the problem
   ...
 }).ToList();

casting error say string not cast to the GrandTotal

CodePudding user response：

I think the value in the column is a string. Just because a GrandTotal has a string does not mean it is a string. Cast can only perform is-a conversions. You'll have to make a new object and assign the string to the relevant property

List<MapValueFields> items = viewLaundry.ToTable().Rows.Cast<DataRow>().Select(t => new MapValueFields()
 {
   Amount = new GrandTotal { DoubleValue = t.Field<string>("Total Amount") 
   ...
 }).ToList();

You could also use (string)t["Total Amount"] for a more compact syntax

CodePudding user response：

In case for other users

Amount = new GrandTotal() { DoubleValue = t.Field<string>("Total Amount") },