Simplest way to set default entity value in separate partial class

Question

This is beginning of my auto generated class Customer:

namespace Winpro
{
using System;
using System.Collections.Generic;

public partial class Customer
{
    public Customer()
    {
        this.Blocked = false;
        this.Code = "#00000";
        this.RuleId = 1;
        this.LocationId = 1;
        this.Contacts = new ObservableListSource<Contact>();
    }

    public int Id { get; set; }
    public string Name { get; set;
    public System.DateTime Added { get; set; }
    ...

Why I can't extend class in this way.

namespace Winpro
{
public partial class Customer
{
    public Customer()
    {
        this.Added = DateTime.Now;
    }

Looking for simple example of setting default values in separate class or override SaveChanges() method.

Thanks

score 1 · Accepted Answer · answered Jan 23 '14 at 16:33

1

A partial class is a class divided in multiple files. It is still a single class, and you can't have two constructors with the same signature.

You can try:

Define a new constructor which takes parameter for DateTime
Call the default constructor with this
Assign the value to the Added property from the parameter

namespace Winpro
{
public partial class Customer
{
    public Customer(DateTime parameterAdded)
     : this() //call the default constructor
    {
        this.Added = parameterAdded; //DateTime.Now;
    }

answered Jan 23 '14 at 16:33

Habib

219,104
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407
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I'm still getting error when I try to insert into db : `The conversion of a datetime2 data type to a datetime data type resulted in an out-of-range value.` While values set up in the default constructor works well – Carlo Jan 23 '14 at 16:49
@Carlo, that seems like a different issue, you can see this question http://stackoverflow.com/questions/4608734/the-conversion-of-a-datetime2-data-type-to-a-datetime-data-type-resulted-in-an-o – Habib Jan 23 '14 at 16:51
Have read many Q&A, even ask my own like http://stackoverflow.com/questions/21295123/dbcontext-entity-framework-datetime-now-fields but I just don't get it. When I drag controls on my form and call customerBindingSource.AddNew() I want to set default values for fields. With values in default constructor everything work well but not for values defined in my second part of partial class. Maybe I don't understand how to use your example? – Carlo Jan 23 '14 at 17:01

Alexandre Rondeau · Answer 2 · 2014-01-23T16:46:15.830

0

Go with a partial method

In the generated class

public partial class Customer
{
    public Customer()
    {
        this.Blocked = false;
        this.Code = "#00000";
        this.RuleId = 1;
        this.LocationId = 1;
        this.Contacts = new ObservableListSource<Contact>();
        AdditionnalInitialisation();
    }

    partial void AdditionnalInitialisation();

In your extension:

public partial class Customer
{
    partial void AdditionnalInitialisation()
    {
        this.Added = DateTime.Now;
    }
}

edited Jan 23 '14 at 16:46

answered Jan 23 '14 at 16:33

Alexandre Rondeau

2,667
24
31

Cannot add anything into generated class because manual changes to this file will be overwritten if the code is regenerated? – Carlo Jan 23 '14 at 16:47
Which version of EF are you using? – Alexandre Rondeau Jan 23 '14 at 17:02

Simplest way to set default entity value in separate partial class

2 Answers2