DXValidationProvider.SetValidationRule(Control, ValidationRuleBase) Method
Associates a validation rule with the specified BaseEdit descendant.
Namespace: DevExpress.XtraEditors.DXErrorProvider
Assembly: DevExpress.XtraEditors.v18.2.dll
Declaration
[DXCategory("Data")]
[DefaultValue(null)]
public virtual void SetValidationRule(
Control control,
ValidationRuleBase rule
)Parameters
| Name | Type | Description |
|---|---|---|
| control | Control | A BaseEdit descendant that represents the editor. |
| rule | DevExpress.XtraEditors.DXErrorProvider.ValidationRuleBase | A DevExpress.XtraEditors.DXErrorProvider.ValidationRuleBase descendant that represents the validation rule. |
Remarks
The DXValidationProvider has two built-in validation rules:
CompareAgainstControlValidationRule
Compares the values of two editors – determines whether one is less than, equal to or greater than the other.
ConditionValidationRule
Checks whether an editor’s value matches the specified condition (‘BeginsWith’, ‘Between’, ‘IsBlank’, etc.).
It’s also possible to implement a custom validation rule. To do this, create a ValidationRule descendant and override the Validate method (see the example).
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.”.
using DevExpress.XtraEditors.DXErrorProvider;
// ...
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);
// 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;
}
}
Related GitHub Examples
The following code snippets (auto-collected from DevExpress Examples) contain references to the SetValidationRule(Control, ValidationRuleBase) method.
Note
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