Generic List Problem

  • Thread starter Thread starter Radenko Zec
  • Start date Start date
R

Radenko Zec

Hi i have generic list problem with DAL code.


class UlazTotal

{




private System.DateTime uT_DATUMField;

private string rA_SIFRAField;

private decimal uT_IZNOSField;

..........

public System.DateTime UT_DATUM

{

get

{return this.uT_DATUMField;}

set

{this.uT_DATUMField = value;}

}


public string RA_SIFRA

{

get

{return this.rA_SIFRAField;}

set

{this.rA_SIFRAField = value;}

}


public decimal UT_IZNOS

{

get

{return this.uT_IZNOSField;}

set

{this.uT_IZNOSField = value;}

}.........................


}

I want to make generic method for getting all data from any class in solution.

public static List<T> GetAll<T>(List<T> source) where T: new()

{

List<T> lista = new List<T>();

SqlParameter[] parameters =

{};

SqlDataReader dr = SqlHelper.ExecuteReader(NoviTemplate.SqlHelper.ConnStr(), CommandType.StoredProcedure, "sp_UlazTotal_GetAll");

while (dr.Read())

{

T obj;

obj=new T();

Read(obj, dr); /////////////////HERE I GET ERROR

}

dr.Close();

return lista;

}



private static void Read(UlazTotal ulazTotal, SqlDataReader dr)

{

UlazTotal ulazTotal = new UlazTotal() ;

ulazTotal.UT_DATUM = Convert.ToDateTime(dr["UT_DATUM"].ToString());

ulazTotal.RA_SIFRA = dr["RA_SIFRA"].ToString();

ulazTotal.UT_IZNOS = Convert.ToDecimal(dr["UT_IZNOS"].ToString());

...............

}



How to make Generic Read method that accept any class (not ulazTotal class) and populate properties of any class with data from reader?



Thanks
 
Well, you aren't going to be able to use the properties of the class
in this way, so I wouldn't even bother typing it... you are going to
have to use reflection or component-model access - something like:

void Read(object obj, IDataReader reader) {
PropertyDescriptorCollection props =
TypeDescriptor.GetProperties(obj);
for(int field = 0; field < reader.Fields; field++) {
PropertyDescriptor prop = props[reader.GetName(field)];
if(prop!=nulll) {
prop.SetValue(obj, reader[field]);
}
}
}

However - this is a very crude approach; perhaps look at ORMs like
NHibernate? Or LINQ in .NET 3.5? In these cases the object type comes
into play, so I might make it:

void Read<T>(T obj, IDataReader reader) {...}

Marc
 
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