DataFormView.ValidateForm Event
Allows you to validate all data editors on the form.
Namespace: DevExpress.Maui.DataForm
Assembly: DevExpress.Maui.Editors.dll
NuGet Package: DevExpress.Maui.Editors
Declaration
public event DataFormValidationEventHandler ValidateForm
Event Data
The ValidateForm event's data class is DataFormValidationEventArgs. The following properties provide information specific to this event:
Property | Description |
---|---|
DataObject | Gets or sets the data object that is associated with the data form. |
Errors | Provides access to a dictionary of error messages for data fields. Keys are data field names. Values are error messages. Error messages are displayed below data editors on the form. |
HasErrors | Gets or sets whether the data form is valid. |
NewValues | Provides access to a dictionary of new values that should be validated. Keys are data field names. |
Remarks
You can handle the following events to validate user input:
ValidateProperty—allows you to validate a specific field on the form. Use the PropertyName event argument to determine the processed data field. The CurrentValue and NewValue arguments specify the current data field value and the value that should be validated. The
DataFormView
raises theValidateProperty
event only if theCurrentValue
andNewValue
are different. If the new value is not valid, set the HasError argument to true and use the ErrorText argument to notify the user about the error.ValidateForm
—allows you to validate all data fields on the form. This event stores new values and error messages in dictionaries, where keys are data field names.
See the following topic for more information: Validate User Input in Data Form for .NET MAUI.
Example
The example below requires a phone number or email address.
using DevExpress.Maui.DataForm;
// ...
public partial class MainPage : ContentPage {
public MainPage() {
InitializeComponent();
dataForm.DataObject = new PersonalInfo();
dataForm.ValidateForm += dataForm_ValidateForm;
}
private void dataForm_ValidateForm(object sender, DataFormValidationEventArgs e) {
if(e.NewValues["Email"] == null && e.NewValues["PhoneNumber"] == null) {
e.HasErrors = true;
e.Errors["Email"] = e.Errors["PhoneNumber"] = "Email address or phone number is required.";
}
}
}