windowsforms-2387-common-features-data-binding-binding-controls-to-data-created-at-runtime.md
DevExpress data-aware .NET WinForms controls can be bound to databases, XML files and lists of data created at runtime. This topic shows you how to bind controls to lists of data.
Suppose you have an object that is a data record and a list of these records should be displayed in a data-aware control. To allow this list to be bound to a control, you can do one of the following:
The simplest way to create a list is to use the BindingList<> generic type.
Consider a sample MyRecord class encapsulating a data record:
public class MyRecord {
public int ID { get; set; }
public string Country { get; set; }
public string Name { get; set; }
public MyRecord(int id, string name, string country) {
ID = id;
Name = name;
Country = country;
}
}
A list of MyRecord objects can be created and bound to a data-aware control as follows:
BindingList<MyRecord> list = new BindingList<MyRecord>();
myDataAwareControl.DataSource = list;
To populate the list with data, you can use the following code:
list.Add(new MyRecord(0, "Steven Baum", "USA"));
list.Add(new MyRecord(1, "Robert McKinsey", "USA"));
list.Add(new MyRecord(2, "Robert McKinsey", "UK"));
list.Add(new MyRecord(3, "Daniella Lloyd", "UK"));
When bound to a BindingList<> object, the data-aware control automatically subscribes to the BindingList<>.ListChanged event to receive notifications and update itself when the underlying data changes.
Instead of creating custom lists, you can use a DataTable object and fill it with data at runtime, if this better suits your requirements.
As stated above, the control’s data source can implement one of three interfaces. The following describes the difference between the data sources that implement each interface type.
This example binds a GridControl to a collection of custom Record objects and demonstrates the following features:
Assigning an inplace editor (combo box) to a column
Specifying a column’s display name and data format by applying DataAnnotation attributes to Record class properties
Two ways of changing cell values - at the data source and grid level.
Highlighting cell values that meet a condition
using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Repository;
using DevExpress.XtraGrid;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace GridBoundToRuntimeCreatedData {
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e) {
gridControl1.DataSource = DataHelper.GetData(10);
// The grid automatically creates columns for the public fields found in the data source.
// Calling the gridView1.PopulateColumns method is not required unless the gridView1.OptionsBehavior.AutoPopulateColumns is disabled
// Create a ComboBox editor that shows available companies in the Company column
RepositoryItemComboBox riComboBox = new RepositoryItemComboBox();
riComboBox.Items.AddRange(DataHelper.companies);
gridControl1.RepositoryItems.Add(riComboBox);
gridView1.Columns["CompanyName"].ColumnEdit = riComboBox;
// Specify a different null value text presentation for the Image column
gridView1.Columns["Image"].RealColumnEdit.NullText = "[load image]";
//Highlight the RequiredDate cells that match a certain condition.
GridFormatRule gridFormatRule = new GridFormatRule();
FormatConditionRuleValue formatConditionRuleValue = new FormatConditionRuleValue();
gridFormatRule.Column = gridView1.Columns["RequiredDate"];
formatConditionRuleValue.PredefinedName = "Red Bold Text";
formatConditionRuleValue.Condition = FormatCondition.Greater;
formatConditionRuleValue.Value1 = DateTime.Today;
gridFormatRule.Rule = formatConditionRuleValue;
gridFormatRule.ApplyToRow = false;
gridView1.FormatRules.Add(gridFormatRule);
gridView1.BestFitColumns();
}
private void btnClearPayment_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e) {
//Change a cell value at the data source level to see the INotifyPropertyChanged interface in action.
gridView1.CloseEditor();
Record rec = gridView1.GetFocusedRow() as Record;
if (rec == null) return;
rec.Value = 0;
}
private void btnSetPayment_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e) {
//Change a cell value at the grid level
gridView1.SetFocusedRowCellValue("Value", 999);
}
}
public class Record : INotifyPropertyChanged {
public Record() {
}
int id;
public int ID {
get { return id; }
set {
if (id != value) {
id = value;
OnPropertyChanged();
}
}
}
string text;
[DisplayName("Company")]
public string CompanyName {
get { return text; }
set {
if (text != value) {
if (string.IsNullOrEmpty(value))
throw new Exception();
text = value;
OnPropertyChanged();
}
}
}
Nullable<decimal> val;
[DataType(DataType.Currency)]
[DisplayName("Payment")]
public Nullable<decimal> Value {
get { return val; }
set {
if (val != value) {
val = value;
OnPropertyChanged();
}
}
}
DateTime dt;
[DisplayFormat(DataFormatString = "d")]
public DateTime RequiredDate {
get { return dt; }
set {
if (dt != value) {
dt = value;
OnPropertyChanged();
}
}
}
bool state;
public bool Processed {
get { return state; }
set {
if (state != value) {
state = value;
OnPropertyChanged();
}
}
}
Image image;
public Image Image {
get { return image; }
set {
if (image != value) {
image = value;
OnPropertyChanged();
}
}
}
public override string ToString() {
return string.Format("ID = {0}, Text = {1}", ID, CompanyName);
}
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged([CallerMemberName] string propertyName = "") {
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
public class DataHelper {
public static string[] companies = new string[] { "Hanari Carnes", "Que Delícia", "Romero y tomillo", "Mère Paillarde",
"Comércio Mineiro", "Reggiani Caseifici", "Maison Dewey" };
public static Image[] images = new Image[] {
global::GridBoundToRuntimeCreatedData.Properties.Resources.palette_16x16,
global::GridBoundToRuntimeCreatedData.Properties.Resources.viewonweb_16x16,
global::GridBoundToRuntimeCreatedData.Properties.Resources.design_16x16,
global::GridBoundToRuntimeCreatedData.Properties.Resources.piestylepie_16x16,
global::GridBoundToRuntimeCreatedData.Properties.Resources.alignhorizontaltop2_16x16,
null
};
public static BindingList<Record> GetData(int count) {
BindingList<Record> records = new BindingList<Record>();
Random rnd = new Random();
for (int i = 0; i < count; i++) {
int n = rnd.Next(10);
records.Add(new Record() {
ID = i + 100,
CompanyName = companies[i % companies.Length],
RequiredDate = DateTime.Today.AddDays(n - 5),
Value = i % 2 == 0 ? (i + 1) * 123 : i * 231,
Processed = i % 2 == 0,
Image = images[i % images.Length],
});
};
return records;
}
}
}
Imports DevExpress.XtraEditors
Imports DevExpress.XtraEditors.Repository
Imports DevExpress.XtraGrid
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.ComponentModel.DataAnnotations
Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Runtime.CompilerServices
Imports System.Text
Imports System.Threading.Tasks
Imports System.Windows.Forms
Namespace GridBoundToRuntimeCreatedData
Partial Public Class Form1
Inherits Form
Public Sub New()
InitializeComponent()
End Sub
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
gridControl1.DataSource = DataHelper.GetData(10)
' The grid automatically creates columns for the public fields found in the data source.
' Calling the gridView1.PopulateColumns method is not required unless the gridView1.OptionsBehavior.AutoPopulateColumns is disabled
' Create a ComboBox editor that shows available companies in the Company column
Dim riComboBox As New RepositoryItemComboBox()
riComboBox.Items.AddRange(DataHelper.companies)
gridControl1.RepositoryItems.Add(riComboBox)
gridView1.Columns("CompanyName").ColumnEdit = riComboBox
' Specify a different null value text presentation for the Image column
gridView1.Columns("Image").RealColumnEdit.NullText = "[load image]"
'Highlight the RequiredDate cells that match a certain condition.
Dim gridFormatRule As New GridFormatRule()
Dim formatConditionRuleValue As New FormatConditionRuleValue()
gridFormatRule.Column = gridView1.Columns("RequiredDate")
formatConditionRuleValue.PredefinedName = "Red Bold Text"
formatConditionRuleValue.Condition = FormatCondition.Greater
formatConditionRuleValue.Value1 = Date.Today
gridFormatRule.Rule = formatConditionRuleValue
gridFormatRule.ApplyToRow = False
gridView1.FormatRules.Add(gridFormatRule)
gridView1.BestFitColumns()
End Sub
Private Sub btnClearPayment_ItemClick(ByVal sender As Object, ByVal e As DevExpress.XtraBars.ItemClickEventArgs) Handles btnClearPayment.ItemClick
'Change a cell value at the data source level to see the INotifyPropertyChanged interface in action.
gridView1.CloseEditor()
Dim rec As Record = TryCast(gridView1.GetFocusedRow(), Record)
If rec Is Nothing Then
Return
End If
rec.Value = 0
End Sub
Private Sub btnSetPayment_ItemClick(ByVal sender As Object, ByVal e As DevExpress.XtraBars.ItemClickEventArgs) Handles btnSetPayment.ItemClick
'Change a cell value at the grid level
gridView1.SetFocusedRowCellValue("Value", 999)
End Sub
End Class
Public Class Record
Implements INotifyPropertyChanged
Public Sub New()
End Sub
Private id_Renamed As Integer
Public Property ID() As Integer
Get
Return id_Renamed
End Get
Set(ByVal value As Integer)
If id_Renamed <> value Then
id_Renamed = value
OnPropertyChanged()
End If
End Set
End Property
Private text As String
<DisplayName("Company")> _
Public Property CompanyName() As String
Get
Return text
End Get
Set(ByVal value As String)
If text <> value Then
If String.IsNullOrEmpty(value) Then
Throw New Exception()
End If
text = value
OnPropertyChanged()
End If
End Set
End Property
Private val? As Decimal
<DataType(DataType.Currency), DisplayName("Payment")> _
Public Property Value() As Decimal?
Get
Return val
End Get
Set(ByVal value? As Decimal)
If Not val.Equals(value) Then
val = value
OnPropertyChanged()
End If
End Set
End Property
Private dt As Date
<DisplayFormat(DataFormatString := "d")> _
Public Property RequiredDate() As Date
Get
Return dt
End Get
Set(ByVal value As Date)
If dt <> value Then
dt = value
OnPropertyChanged()
End If
End Set
End Property
Private state As Boolean
Public Property Processed() As Boolean
Get
Return state
End Get
Set(ByVal value As Boolean)
If state <> value Then
state = value
OnPropertyChanged()
End If
End Set
End Property
Private image_Renamed As Image
Public Property Image() As Image
Get
Return image_Renamed
End Get
Set(ByVal value As Image)
If image_Renamed IsNot value Then
image_Renamed = value
OnPropertyChanged()
End If
End Set
End Property
Public Overrides Function ToString() As String
Return String.Format("ID = {0}, Text = {1}", ID, CompanyName)
End Function
Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged
Protected Sub OnPropertyChanged(<CallerMemberName> Optional propertyName As String = "")
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
End Sub
End Class
Public Class DataHelper
Public Shared companies() As String = { "Hanari Carnes", "Que Delícia", "Romero y tomillo", "Mère Paillarde", "Comércio Mineiro", "Reggiani Caseifici", "Maison Dewey" }
Public Shared images() As Image = { My.Resources.palette_16x16, My.Resources.viewonweb_16x16, My.Resources.design_16x16, My.Resources.piestylepie_16x16, My.Resources.alignhorizontaltop2_16x16, Nothing }
Public Shared Function GetData(ByVal count As Integer) As BindingList(Of Record)
Dim records As New BindingList(Of Record)()
Dim rnd As New Random()
For i As Integer = 0 To count - 1
Dim n As Integer = rnd.Next(10)
records.Add(New Record() With { _
.ID = i + 100, _
.CompanyName = companies(i Mod companies.Length), _
.RequiredDate = Date.Today.AddDays(n - 5), _
.Value = If(i Mod 2 = 0, (i + 1) * 123, i * 231), _
.Processed = i Mod 2 = 0, _
.Image = images(i Mod images.Length) _
})
Next i
Return records
End Function
End Class
End Namespace
Tip
See the following help topic for additional information: Bind to Objects with Collection Properties.
See Also