DXValidationProvider.Validate(Control) Method

Validates the specified editor associated with the DXValidationProvider.

Namespace: DevExpress.XtraEditors.DXErrorProvider

Assembly: DevExpress.XtraEditors.v19.2.dll

Declaration

C#

public bool Validate(
    Control control
)

VB.NET

Public Function Validate(
    control As Control
) As Boolean

Parameters

Name	Type	Description
control	Control	A Control object or descendant that represents the editor to be validated.

Returns

Type	Description
Boolean	true if the editor is successfully validated; otherwise, false.

Remarks

Call the Validate method to validate the specified control. To validate controls automatically, set the ValidationMode property to Auto.

Example

This example demonstrates how to validate data via the DXValidationProvider component. In this example, validation rules (built-in and custom) are created in code, and associated with editors using the DXValidationProvider.SetValidationRule method.

The CustomValidationRule class represents a custom validation rule that checks whether the editor’s value begins with “Dr.”, “Mr.”, “Mrs.”, “Miss” or “Ms.”.

C#

using DevExpress.XtraEditors.DXErrorProvider;

// Validate editors manually (when the OK button is clicked)
dxValidationProvider1.ValidationMode = ValidationMode.Manual;

// ...
ConditionValidationRule containsValidationRule = new ConditionValidationRule();
containsValidationRule.ConditionOperator = ConditionOperator.Contains;
containsValidationRule.Value1 = '@';
containsValidationRule.ErrorText = "Please enter a valid email";
containsValidationRule.ErrorType = ErrorType.Warning;

CompareAgainstControlValidationRule compValidationRule = 
    new CompareAgainstControlValidationRule();
compValidationRule.Control = notEmptyTextEdit;
compValidationRule.CompareControlOperator = CompareControlOperator.Equals;
compValidationRule.ErrorText = "Please enter a value that equals to the first editor's value";
compValidationRule.CaseSensitive = true;

CustomValidationRule customValidationRule = new CustomValidationRule();
customValidationRule.ErrorText = "Please enter a valid person name";
customValidationRule.ErrorType = ErrorType.Warning;

dxValidationProvider1.SetValidationRule(containsTextEdit, containsValidationRule);
dxValidationProvider1.SetValidationRule(compareTextEdit, compValidationRule);
dxValidationProvider1.SetValidationRule(customTextEdit, customValidationRule);


private void buttonOk_Click(object sender, EventArgs e) {
    dxValidationProvider1.Validate();
}

// Represents a custom validation rule.
public class CustomValidationRule : ValidationRule {
    public override bool Validate(Control control, object value) {
        string str = (string)value;
        string[] values = new string[] { "Dr.", "Mr.", "Mrs.", "Miss", "Ms." };
        bool res = false;
        foreach(string val in values) {
            if(ValidationHelper.Validate(str, ConditionOperator.BeginsWith, 
                val, null, null, false)) {
                string name = str.Substring(val.Length);
                if(name.Trim().Length > 0) res = true;
            }
        }
        return res;
    }
}

VB.NET

Imports DevExpress.XtraEditors.DXErrorProvider

' Validate editors manually (when the OK button is clicked)
dxValidationProvider1.ValidationMode = ValidationMode.Manual
' ...
Dim containsValidationRule As New ConditionValidationRule()
containsValidationRule.ConditionOperator = ConditionOperator.Contains
containsValidationRule.Value1 = "@"
containsValidationRule.ErrorText = "Please enter a valid email"
containsValidationRule.ErrorType = ErrorType.Warning

Dim compValidationRule As New CompareAgainstControlValidationRule()
compValidationRule.Control = notEmptyTextEdit
compValidationRule.CompareControlOperator = CompareControlOperator.Equals
compValidationRule.ErrorText = "Please enter a value that equals to the first editor's value"
compValidationRule.CaseSensitive = True

Dim customValidationRule As New CustomValidationRule()
customValidationRule.ErrorText = "Please enter a valid person name"
customValidationRule.ErrorType = ErrorType.Warning

dxValidationProvider1.SetValidationRule(containsTextEdit, containsValidationRule)
dxValidationProvider1.SetValidationRule(compareTextEdit, compValidationRule)
dxValidationProvider1.SetValidationRule(customTextEdit, customValidationRule)

Private Sub ButtonOK_Click(sender As Object, e As EventArgs) Handles ButtonOK.Click
    dxValidationProvider1.Validate()
End Sub


' Represents a custom validation rule.
Public Class CustomValidationRule
   Inherits ValidationRule

   Public Overrides Function Validate(control As Control, value As Object) As Boolean
      Dim str As String = CStr(value)
      Dim values() As String = {"Dr.", "Mr.", "Mrs.", "Miss", "Ms."}
      Dim res As Boolean = False
      Dim val As String
      For Each val In  values
         If ValidationHelper.Validate(str, ConditionOperator.BeginsWith, _ 
             val, Nothing, Nothing, False) Then
            Dim name As String = str.Substring(val.Length)
            If name.Trim().Length > 0 Then
               res = True
            End If
         End If
      Next val
      Return res
   End Function
End Class