We recommend that you use the xamDataGrid control instead of the xamGrid control. The xamGrid is being planned for retirement over the next few years and will not receive any new features. We will continue to provide support and critical bug fixes for the xamGrid during this time. For help or questions on migrating your codebase to the xamDataGrid, please contact support.
RequireEmptyConstructor Exception
When your end user attempts to add a new row to the xamGrid™ control, the grid initially tries to create a new instance of the data object type that is bound to the grid.
For example, if your grid is bound to a list of customer objects, when your end user tries to add a new row, the grid will create a new Customer object.
The topic will describe the scenario of adding a new row.
In order for this to be successful, the object must include a default constructor so that the grid can use this to create a new object instance. However, in certain situations you may need to bind to a collection of objects that does not contain a default constructor. If there is no default constructor, the xamGrid control will throw a RequireEmptyConstructor exception when your end user attempts to add a new row to the control.
To rectify this problem ensure that your object has a default constructor.
public class Person
{
public Person()
{
}
public Person(string firstName, string lastName, int age, double height, DateTime born, string address)
{
this.FirstName = firstName;
this.LastName = lastName;
this.Age = age;
this.Height = height;
this.Born = born;
this.Address = address;
}
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public double Height { get; set; }
public DateTime Born { get; set; }
public string Address { get; set; }
}
Since it is not always possible to modify the object yourself, you can handle the xamGrid control’s DataObjectRequested event to intercept the request for a new object. This event is raised when the DataManager is going to attempt to create a new underlying data object. In this event’s parameters is a member called e. NewObject. You should set this object to a new instance of your data object and this will be used by the grid instead of trying to create a new object.
ig.DataObjectRequested += new EventHandler<DataObjectCreationEventArgs>(ig_DataObjectRequsted);
void ig_DataObjectRequsted(object sender, DataObjectCreationEventArgs e)
{
if (e.ObjectType == typeof(Person))
e.NewObject = new Person(null, null, 0, 0, DateTime.Today, null);
}
