# Validation For the need of the validation process we made two events (**ItemValidating, ItemValidated**) that are firing when the **Validating** and **Validated** events occur in the editors. **RadDataLayout** provides three different ways to show to the users that some editors do not match the validation criteria – *Validation Label*, *Error Provider* and *Validation Panel*. In the following tutorial we will demonstrate how to use a validation panel together with Error provider. 1\. For the purpose of this tutorial, we will create a new class **Employee** with a couple of exposed properties. By binding **RadDataLayout** to object from this type we will generate several items: ```C# public class Employee { [DisplayName("First Name")] public string FirstName { get; set; } [DisplayName("Family Name")] public string LastName { get; set; } public string Occupation { get; set; } public int Salary { get; set; } public DateTime StartingDate { get; set; } public bool IsMarried { get; set; } } ``` ```VB.NET Public Class Employee _ Public Property FirstName() As String Get Return m_FirstName End Get Set(value As String) m_FirstName = value End Set End Property Private m_FirstName As String _ Public Property LastName() As String Get Return m_LastName End Get Set(value As String) m_LastName = value End Set End Property Private m_LastName As String Public Property Occupation() As String Get Return m_Occupation End Get Set(value As String) m_Occupation = value End Set End Property Private m_Occupation As String Public Property Salary() As Integer Get Return m_Salary End Get Set(value As Integer) m_Salary = value End Set End Property Private m_Salary As Integer Public Property StartingDate() As DateTime Get Return m_StartingDate End Get Set(value As DateTime) m_StartingDate = value End Set End Property Private m_StartingDate As DateTime Public Property IsMarried() As Boolean Get Return m_IsMarried End Get Set(value As Boolean) m_IsMarried = value End Set End Property Private m_IsMarried As Boolean End Class ``` ```C# this.radDataLayout1.DataSource = new Employee() { FirstName = "Sarah", LastName = "Blake", Occupation = "Supplied Manager", StartingDate = new DateTime(2005, 04, 12), Salary = 1500, IsMarried = true }; ``` ```VB.NET Me.RadDataLayout1.DataSource = New Employee() With { .FirstName = "Sarah", .LastName = "Blake", .Occupation = "Supplied Manager", .StartingDate = New DateTime(2005, 4, 12), .Salary = 1500, .IsMarried = True } ``` > caption Figure 1: RadDataLayout Initialized ![WinForms RadDataLayout Initialized](https://www.telerik.com/products/winforms/documentation/assets/522db4bf60199523563c01dc5b233adb/datalayout-validation001.png) 2\. Set the **ShowValidationPanel** property to *true*. This will display the panel below the editors: ```C# this.radDataLayout1.ShowValidationPanel = true; ``` ```VB.NET Me.RadDataLayout1.ShowValidationPanel = True ``` 3\. Set a padding to the **LayoutControlContainerElement** so that the error icons are visible. A suitable place to perform this operation is the handler of the **BindingCreated**. ```C# private void radDataLayout1_BindingCreated(object sender, Telerik.WinControls.UI.BindingCreatedEventArgs e) { this.radDataLayout1.LayoutControl.ContainerElement.Padding = new Padding(0, 0, 20, 0); } ``` ```VB.NET Private Sub RadDataLayout1_BindingCreated(sender As Object, e As BindingCreatedEventArgs) Me.RadDataLayout1.LayoutControl.ContainerElement.Padding = New Padding(0, 0, 20, 0) End Sub ``` 4\. Subscribe to the **ItemValidated** event of **RadDataEntry**: ```C# private void radDataLayout1_ItemValidated(object sender, Telerik.WinControls.UI.DataLayoutItemValidatedEventArgs e) { Employee employee = this.radDataLayout1.CurrentObject as Employee; if (e.Item.Text == "First Name") { if (employee.FirstName.Length < 2 || employee.FirstName.Length > 15) { e.ErrorProvider.SetError((sender as Control), "First Name should be between 2 and 15 chars long."); if (!this.radDataLayout1.ValidationPanel.PanelContainer.Controls.ContainsKey("FirstName")) { RadLabel label = new RadLabel(); label.Name = "FirstName"; label.Text = "FirstName : First Name should be between 2 and 15 chars long."; label.Dock = DockStyle.Top; label.AutoSize = false; label.BackColor = Color.Transparent; this.radDataLayout1.ValidationPanel.PanelContainer.Controls.Add(label); } } else { e.ErrorProvider.Clear(); this.radDataLayout1.ValidationPanel.PanelContainer.Controls.RemoveByKey("FirstName"); } } else if (e.Item.Text == "Family Name") { if (employee.LastName.Length < 2 || employee.LastName.Length > 15) { e.ErrorProvider.SetError((sender as Control), "Last Name should be between 2 and 15 chars long."); if (!this.radDataLayout1.ValidationPanel.PanelContainer.Controls.ContainsKey("LastName")) { RadLabel label = new RadLabel(); label.Name = "LastName"; label.Text = "LastName : Last Name should be between 2 and 15 chars long."; label.Dock = DockStyle.Top; label.AutoSize = false; label.BackColor = Color.Transparent; this.radDataLayout1.ValidationPanel.PanelContainer.Controls.Add(label); } } else { e.ErrorProvider.Clear(); this.radDataLayout1.ValidationPanel.PanelContainer.Controls.RemoveByKey("LastName"); } } else if (e.Item.Text == "Salary") { if (employee.Salary < 1400 || employee.Salary > 1800) { e.ErrorProvider.SetError((sender as Control), "Salary should be in range 1500 - 1700."); if (!this.radDataLayout1.ValidationPanel.PanelContainer.Controls.ContainsKey("Salary")) { RadLabel label = new RadLabel(); label.Name = "Salary"; label.Text = "Salary : Salary should be in range 1500 - 1700."; label.Dock = DockStyle.Top; label.AutoSize = false; label.BackColor = Color.Transparent; this.radDataLayout1.ValidationPanel.PanelContainer.Controls.Add(label); } } else { e.ErrorProvider.Clear(); this.radDataLayout1.ValidationPanel.PanelContainer.Controls.RemoveByKey("Salary"); } } } ``` ```VB.NET Private Sub radDataLayout1_ItemValidated(sender As Object, e As Telerik.WinControls.UI.DataLayoutItemValidatedEventArgs) Dim employee As Employee = TryCast(Me.RadDataLayout1.CurrentObject, Employee) If e.Item.Text = "First Name" Then If employee.FirstName.Length < 2 OrElse employee.FirstName.Length > 15 Then e.ErrorProvider.SetError(TryCast(sender, Control), "First Name should be between 2 and 15 chars long.") If Not Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.ContainsKey("FirstName") Then Dim label As New RadLabel() label.Name = "FirstName" label.Text = "FirstName : First Name should be between 2 and 15 chars long." label.Dock = DockStyle.Top label.AutoSize = False label.BackColor = Color.Transparent Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.Add(label) End If Else e.ErrorProvider.Clear() Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.RemoveByKey("FirstName") End If ElseIf e.Item.Text = "Family Name" Then If employee.LastName.Length < 2 OrElse employee.LastName.Length > 15 Then e.ErrorProvider.SetError(TryCast(sender, Control), "Last Name should be between 2 and 15 chars long.") If Not Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.ContainsKey("LastName") Then Dim label As New RadLabel() label.Name = "LastName" label.Text = "LastName : Last Name should be between 2 and 15 chars long." label.Dock = DockStyle.Top label.AutoSize = False label.BackColor = Color.Transparent Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.Add(label) End If Else e.ErrorProvider.Clear() Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.RemoveByKey("LastName") End If ElseIf e.Item.Text = "Salary" Then If employee.Salary < 1400 OrElse employee.Salary > 1800 Then e.ErrorProvider.SetError(TryCast(sender, Control), "Salary should be in range 1500 - 1700.") If Not Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.ContainsKey("Salary") Then Dim label As New RadLabel() label.Name = "Salary" label.Text = "Salary : Salary should be in range 1500 - 1700." label.Dock = DockStyle.Top label.AutoSize = False label.BackColor = Color.Transparent Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.Add(label) End If Else e.ErrorProvider.Clear() Me.RadDataLayout1.ValidationPanel.PanelContainer.Controls.RemoveByKey("Salary") End If End If End Sub ``` > caption Figure 2: Validaton Errors ![WinForms RadDataLayout Validaton Errors](https://www.telerik.com/products/winforms/documentation/assets/632ac07332a8975915f242e8d24d55c4/datalayout-validation002.png) In this tutorial we also used an error provider to show error icon next to the editors. You can read more about Microsoft Error provider here - [ErrorProvider Class](http://msdn.microsoft.com/en-us/library/system.windows.forms.errorprovider%28v=vs.110%29.aspx) ## See Also * [Structure](https://www.telerik.com/products/winforms/documentation/controls/datalayout/structure) * [Getting Started](https://www.telerik.com/products/winforms/documentation/controls/datalayout/getting-started) * [Properties, events and attributes](https://www.telerik.com/products/winforms/documentation/controls/datalayout/properties-events-and-attributes) * [Localization](https://www.telerik.com/products/winforms/documentation/controls/datalayout/localization) * [Change the editor to RadDropDownList](https://www.telerik.com/products/winforms/documentation/controls/dataentry/how-to/change-the-editor-to-a-bound-raddropdownlist) * [Customizing Appearance ](https://www.telerik.com/products/winforms/documentation/controls/datalayout/customizing-appearance/customizing-appearance)