How to: Create and customize a custom GridLookUpEdit control

 How to: Create and customize a custom GridLookUpEdit control

Assume that a GridLookUpEdit control needs to be used in multiple places, and all editors must display data from one predefined data source and contain predefined columns. In this instance, you can create a custom GridLookUpEdit control.

This example shows how to create a custom GridLookUpEdit control, and initialize its properties as required. The structure of descendant classes is based on the code template shown in the Custom Editors.Editors Structure topic.

To customize the control's settings, the OnLoaded method is overridden. In this method, the control's DataSource, columns and some other options are initialized. Note that columns created in this method are not accessible at design time.

C#: using System.Drawing; using System.Reflection; using System.ComponentModel; using System.Windows.Forms; using DevExpress.XtraEditors; using DevExpress.XtraEditors.Repository; using DevExpress.XtraEditors.Registrator; using DevExpress.XtraEditors.Drawing; using DevExpress.XtraEditors.ViewInfo; using DevExpress.XtraGrid.Columns; using DevExpress.XtraGrid.Views.Grid; using System.Data;     namespace DevExpress.MyGridLookUpEditors {       //The attribute that points to the registration method     [UserRepositoryItem("RegisterMyGridLookUpEdit")]     public class RepositoryItemMyGridLookUpEdit : RepositoryItemGridLookUpEdit {           //The static constructor which calls the registration method         static RepositoryItemMyGridLookUpEdit() { RegisterMyGridLookUpEdit(); }           //Initialize new properties         public RepositoryItemMyGridLookUpEdit() {         }           protected override void OnLoaded() {             base.OnLoaded();             if (IsDesignMode) return;             // Create two columns             GridColumn colId = new GridColumn();             colId.FieldName = colId.Caption = "ID";             colId.VisibleIndex = 0;             GridColumn colName = new GridColumn();             colName.FieldName = colName.Caption = "Name";             colName.VisibleIndex = 1;             GridView gView = this.View;             gView.Columns.Clear();             gView.Columns.Add(colId);             gView.Columns.Add(colName);             // Hide the group panel             gView.OptionsView.ShowGroupPanel = true;             // Initialize data source             DisplayMember = "Name";             ValueMember = "ID";             DataSource = GetData();         }           private DataTable GetData() {             DataTable table = new DataTable();             table.Columns.Add(new DataColumn("ID", typeof(int)));             table.Columns.Add(new DataColumn("Name", typeof(string)));             table.Rows.Add(new object[] { 0, "A" });             table.Rows.Add(new object[] { 1, "B" });             table.Rows.Add(new object[] { 2, "C" });             return table;         }             //The unique name for the custom editor         public const string MyGridLookUpEditName = "MyGridLookUpEdit";           //Return the unique name         public override string EditorTypeName { get { return MyGridLookUpEditName; } }           //Register the editor         public static void RegisterMyGridLookUpEdit() {             //Icon representing the editor within a container editor's Designer             Image img = null;               EditorRegistrationInfo.Default.Editors.Add(new EditorClassInfo(MyGridLookUpEditName,               typeof(MyGridLookUpEdit), typeof(RepositoryItemMyGridLookUpEdit),               typeof(GridLookUpEditBaseViewInfo), new ButtonEditPainter(), true, img));         }               //Override the Assign method         public override void Assign(RepositoryItem item) {             BeginUpdate();             try {                 base.Assign(item);                 RepositoryItemMyGridLookUpEdit source =                     item as RepositoryItemMyGridLookUpEdit;                 if (source == null) return;             }             finally {                 EndUpdate();             }         }     }         public class MyGridLookUpEdit : GridLookUpEdit {           //The static constructor which calls the registration method         static MyGridLookUpEdit() {             RepositoryItemMyGridLookUpEdit.RegisterMyGridLookUpEdit(); }           //Initialize the new instance         public MyGridLookUpEdit() {             //...         }           //Return the unique name         public override string EditorTypeName { get { return             RepositoryItemMyGridLookUpEdit.MyGridLookUpEditName; } }           //Override the Properties property         //Simply type-cast the object to the custom repository item type         [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]         public new RepositoryItemMyGridLookUpEdit Properties {             get { return base.Properties as RepositoryItemMyGridLookUpEdit; }         }       } } VB: Imports System.Reflection Imports System.Drawing Imports System.ComponentModel Imports System.Windows.Forms Imports DevExpress.XtraEditors Imports DevExpress.XtraEditors.Repository Imports DevExpress.XtraEditors.Registrator Imports DevExpress.XtraEditors.Drawing Imports DevExpress.XtraEditors.ViewInfo Imports DevExpress.XtraGrid.Columns Imports DevExpress.XtraGrid.Views.Grid   'The attribute that points to the registration method <UserRepositoryItem("RegisterMyGridLookUpEdit")> _ Public Class RepositoryItemMyGridLookUpEdit     Inherits RepositoryItemGridLookUpEdit       'The static constructor which calls the registration method     Shared Sub New()         RegisterMyGridLookUpEdit()     End Sub         'Initialize new properties     Public Sub New()       End Sub       Protected Overrides Sub OnLoaded()         MyBase.OnLoaded()         If IsDesignMode Then Return         ' Create two columns         Dim colId As New GridColumn         colId.FieldName = "ID"         colId.Caption = "ID"         colId.VisibleIndex = 0         Dim colName As New GridColumn         colName.FieldName = "Name"         colName.Caption = "Name"         colName.VisibleIndex = 1         Dim gView As GridView = View         gView.Columns.Clear()         gView.Columns.Add(colId)         gView.Columns.Add(colName)         ' Hide the group panel         gView.OptionsView.ShowGroupPanel = True         ' Initialize data source         DisplayMember = "Name"         ValueMember = "ID"         DataSource = GetData()     End Sub       Public Function GetData() As DataTable         Dim table As New DataTable()         table.Columns.Add(New DataColumn("ID", GetType(Integer)))         table.Columns.Add(New DataColumn("Name", GetType(String)))         table.Rows.Add(New Object() {0, "A"})         table.Rows.Add(New Object() {1, "B"})         table.Rows.Add(New Object() {2, "C"})         Return table     End Function         'The unique name for the custom editor     Public Const MyGridLookUpEditName As String = "MyGridLookUpEdit"       'Return the unique name     Public Overrides ReadOnly Property EditorTypeName() As String         Get             Return MyGridLookUpEditName         End Get     End Property       'Register the editor     Public Shared Sub RegisterMyGridLookUpEdit()         'Icon representing the editor within a container editor's Designer         Dim img As Image = Nothing         EditorRegistrationInfo.Default.Editors.Add(New EditorClassInfo(MyGridLookUpEditName, _           GetType(MyGridLookUpEdit), GetType(RepositoryItemMyGridLookUpEdit), _           GetType(GridLookUpEditBaseViewInfo), New ButtonEditPainter, True, img))     End Sub         'Override the Assign method     Public Overrides Sub Assign(ByVal item As RepositoryItem)         BeginUpdate()         Try             MyBase.Assign(item)             Dim source As RepositoryItemMyGridLookUpEdit = _                 CType(item, RepositoryItemMyGridLookUpEdit)             If source Is Nothing Then Return           Finally             EndUpdate()         End Try     End Sub End Class     Public Class MyGridLookUpEdit     Inherits GridLookUpEdit       'The static constructor which calls the registration method     Shared Sub New()         RepositoryItemMyGridLookUpEdit.RegisterMyGridLookUpEdit()     End Sub       'Return the unique name     Public Overrides ReadOnly Property EditorTypeName() As String         Get             Return RepositoryItemMyGridLookUpEdit.MyGridLookUpEditName         End Get     End Property       'Override the Properties property     'Simply type-cast the object to the custom repository item type     <DesignerSerializationVisibility(DesignerSerializationVisibility.Content)> _     Public Shadows ReadOnly Property Properties() As RepositoryItemMyGridLookUpEdit         Get             Return CType(MyBase.Properties, RepositoryItemMyGridLookUpEdit)         End Get     End Property   End Class