How C # DataTable and list convert to each other

First, the non-generic conversions are done by traversing the DataTable and assigning values to the same fields in the model.

Using the ToList method of LINQ, Non-generic

        Static list<entity> ConvertTo (DataTable DT)

        {

            Null

            Null

            New List<entity> ();

            In dt. Rows

                    New Entity

                    {

                        PID = Int32.Parse (dr["pid"). ToString ()),

                        PName = dr["PName"]. ToString (),

                        Ppass = dr["Ppass"]. ToString (),

                        PADDR = dr["Paddr"]. ToString ()

                    }). ToList ();

            return list;

        }

The code is simple, it's just a loop assignment. Here I use the model test class as follows:

Namespace Datasettoentity.code

{

    Class Entity

    {

        int PID {get; set;}

        String PName {get; set;}

        String Ppass {get; set;}

        String Paddr {get; set;}

    }

}

Generic mode

Then, since the non-generic version is not universal, here we are going to implement it with the generic version, because the generic version is the attribute structure in the unpredictable model, so here we need to introduce reflection to do it.

A generic method that uses reflection

        New ()

        {

            Null

            Null

            New List<t> ();

            Try

            {

                list<New list<string> ();   

                In dt. Columns)

                {

                    Columnsname.add (Datacolumn.columnname); //Get all the table headers

                }

                list = dt. AsEnumerable (). ToList (). convertall<t> (row = getobject<t> (row, columnsname));  //Conversion

                return list;

            }

            catch (Exception ex)

            {

                Null

            }

        }

        Static T getobject<t> (DataRow row, list<new ()

        {

            New T ();

            Try

            {

                "";

                "";

                typeof (T). GetProperties ();

                In properties)  //Traverse property of T

                {

                    Look for header names that can be matched

                    if (!  String. IsNullOrEmpty (columnname))

                    {

                        Value = Row[columnname]. ToString ();

                        if (!  String. IsNullOrEmpty (value)) 

                        {

                            A matching table header exists

                            {

                                Value = Row[columnname]. ToString (). Replace (""). Replace (//extract data from a DataRow 

                                Objproperty.setvalue (obj, Convert.changetype (//assignment Operation

                            }

                            Else

                            {

                                Value = Row[columnname]. ToString (). Replace (//There is a matching table header

                                Objproperty.setvalue (obj, convert.changetype (null);  Assignment Operation 

                            }

                        }

                    }

                }

                return obj;

            }

            Catch

            {

                return obj;

            }

        }

The above is mainly through reflection gets the property name of T, and then matches the header in the DataRow, if it matches, it is assigned value. Here is its simplified version:

Using the reflection of the generic method two

        New ()

        {

            Null

            Null

            New List<t> ();

            typeof (T);

            propertyinfo[] Propertyinfos = type. GetProperties ();  //Gets the properties of the generic type

            list<datacolumn> listcolumns = dt. Columns.cast<datacolumn> (). ToList ();  //Gets the header of the dataset for easy matching

            T T;

            In dt. Rows)   

            {

                New T ();

                In Propertyinfos)

                {

                    Try

                    {

                        DataColumn dcolumn = listcolumns.find (name = = name. ToString (). ToUpper () = = PropertyInfo.Name.ToUpper ());  //See if there is a corresponding column name

                        Null

                            NULL);  //Assigned value

                    }

                    catch (Exception ex)

                    {

                        New Exception (ex. Message);

                    }

                }

                List. ADD (t);

            }

            return list;

        }

As for how to use it, it is very simple to use the following code directly:

list<entity> list = commonutils.converttoex<entity> (dt);

References are only for learning purposes.

How C # DataTable and list convert to each other