Convert DataRow to Object with AutoMapper

2019-01-28 07:11发布

问题:

I can successfully map from IDataReader to a List of objects but when I want to take one DataRow it doesn't seem to work as expected.

Am I missing something simple here?

[TestFixture]
public class AutomapperTest
{
    [Test]
    public void TestMethod1()
    {
        DataTable dt = new DataTable("contact");
        dt.Columns.Add("FirstName");
        dt.Columns.Add("LastName");
        dt.Columns.Add("Line1");
        dt.Columns.Add("Line2");
        dt.Columns.Add("Line3");
        dt.Columns.Add("Suburb");
        dt.Columns.Add("State");
        dt.Columns.Add("Postcode");

        DataRow row = dt.NewRow();
        row.ItemArray = new [] { "Little", "Johnny", 
                                 "1 Random Place", "", "", 
                                 "Windsor", "Qld", "4030" };

        var dest = Mapper.DynamicMap<myObject>(row);

        Assert.AreEqual(row["FirstName"], "Little");
        Assert.IsNotNull(dest);
        Assert.AreEqual(dest.FirstName, "Little");
    }
}

Destination type:

public class myObject
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Line1 { get; set; }
    public string Line2 { get; set; }
    public string Line3 { get; set; }
    public string Suburb { get; set; }
    public string State { get; set; }
    public string Postcode { get; set; }
}

回答1:

You will have to implement your own custom value resolver

https://github.com/AutoMapper/AutoMapper/wiki/Custom-value-resolvers

UPDATE

public class CustomResolver : IValueResolver
{
    public ResolutionResult Resolve(ResolutionResult source)
    {
        return source.New( Convert.ChangeType((source.Context.SourceValue as DataRow)[source.Context.MemberName], source.Context.DestinationType));
    }
}

and here is how to use it

Mapper.CreateMap<DataRow,myObject>().ForAllMembers(m=>m.ResolveUsing<CustomResolver>());
var dest = Mapper.Map<myObject>(row);

I recommend using Dapper. That way your data coming from database will be strongly typed or dynamic, and Automapper should be able to figure out the mappings.

CSV files can be read by Dapper through ODBC, I believe. But for CSV I'd recommend the LinqToCSV Nuget package instead.