SizeAttribute Class

Specifies the maximum number of characters that can be stored in a column which is created to store the data of a property or field.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.1.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

Declaration

C#

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, Inherited = true)]
public sealed class SizeAttribute :
    Attribute

VB.NET

<AttributeUsage(AttributeTargets.Property Or AttributeTargets.Field, Inherited:=True)>
Public NotInheritable Class SizeAttribute
    Inherits Attribute

Remarks

The current version of XPO only supports size definitions for the persistent properties or fields of string data types. If the SizeAttribute isn’t applied to a member, the size of the database column which the member’s data is stored in is specified by the SizeAttribute.DefaultStringMappingFieldSize value.

Note the SizeAttribute affects only the creation of the database column. If the database column already exists, its size is not changed.

Example

The following example applies the SizeAttribute to the FullName and Background properties. The maximum number of characters that can be stored in a database column which the FullName property is mapped to is 128. As for the Background property the unlimited size of the column it is mapped to is specified.

C#

using DevExpress.Xpo;

class Customer : XPObject {
    private string fullName;
    private string background;

    [Size(128)]
    public string FullName {
        get { return fullName; }
        set { SetPropertyValue<string>(nameof(FullName), ref fullName, value); }
    }

    [Size(SizeAttribute.Unlimited)]
    public string Background {
        get { return background; }
        set { SetPropertyValue<string>(nameof(Background), ref background, value); }
    }
}

VB.NET

Imports DevExpress.Xpo

Class Customer
   Inherits XPObject
   Private _FullName As String
   Private _Background As String

   <Size(128)> _
   Public Property FullName() As String
      Get
         Return _FullName
      End Get
      Set(ByVal Value As String)
         SetPropertyValue(Of String)(NameOf(FullName), _FullName, Value)
      End Set
   End Property

   <Size(SizeAttribute.Unlimited)> _
   Public Property Background() As String
      Get
         Return _Background
      End Get
      Set(ByVal Value As String)
         SetPropertyValue(Of String)(NameOf(Background), _Background, Value)
      End Set
   End Property
End Class

Inheritance

Object

Attribute

SizeAttribute