I'm setting DataSource of a DataGridView to List<T> . I enabled by the designer "enable addition".
But that line is not appearing with an asterisk to add new elements.
My code looks like this:
public IEnumerable<Valor> Valores
{
get;
set;
}
private void Form1_Load(object sender, EventArgs ev)
{
if (Valores == null)
{
Valores = new List<Valor>();
}
dataGrid.DataSource = Valores;
}
The problem is that you are trying to put List<T> into DataSource , however a list does not have the capabilities to connect the screen component to the property.
Instead of using a List<T> use a BindingList<T> . This type provides two-way binding , that is, what you add by the grid will be added to the object, and what is added to the object will be added to the grid.
BindingList<T> implements the IBindingList interface that contains the AllowNew property. This property will be false when there is no default constructor for T .
As the example:
public class Pessoa
{
public string Nome { get; set; }
public int Idade { get; set; }
}
When the constructor is empty or omitted (there are no others) it means that you have a default constructor. In this case your grid will show the field to insert a new element.
public BindingList<Pessoa> lista = new BindingList<Pessoa>
{
new Pessoa { Idade = 20, Nome = "Teste 1" },
new Pessoa { Idade = 22, Nome = "Teste 2" },
new Pessoa { Idade = 23, Nome = "Teste 3" },
};
However,ifyourclassdoesnothaveadefaultconstructor:
public class Pessoa
{
public string Nome { get; set; }
public int Idade { get; set; }
public Pessoa(int x) { }
}
IfyouneedtouseList<T>,youcancreateBindingList<T>fromthelist,startapropertyofyourformwith:
ListaBinding = new BindingList<Pessoa>( new List<Pessoa>() );
Use this list to work with the grid and then you can pass the data you want to your other list.