1/5/2023 0 Comments Winforms errorprovider![]() ![]() Private Sub TextBox1_Validating(ByVal Sender As Object, _īyVal e As ) Handles _ĮrrorProvider1.SetError(TextBox1, "Not a numeric value.") The second argument is the error text to display. The first argument of the SetError method specifies which control to display the icon next to. WINFORMS ERRORPROVIDER CODEThe following code tests the validity of the data the user has entered if the data is invalid, the SetError method is called. WINFORMS ERRORPROVIDER WINDOWSFor more information, see How to: Create Event Handlers at Run Time for Windows Forms. In order for this code to run properly, the procedure must be connected to the event. Select the first control and add code to its Validating event handler. To display an error icon when a control's value is invalidĪdd two controls - for example, text boxes - to a Windows Form.Īdd an ErrorProvider component to the form. You must have at least two controls on the form in order to tab between them and thereby invoke the validation code. NET framework BaseNumberConverter class.You can use a Windows Forms ErrorProvider component to display an error icon when the user enters invalid data. RawValue.GetType() = this.Propert圜hain.Last().PropertyType)ĬonvertedValue = (rawValue) Private bool Tr圜onvertValue(object rawValue, out object convertedValue) Validator.ValidateValue(value, context, this.ValidationAttributes) Let controlProperty = control.GetType().GetProperty(dataBinding.PropertyName) Let modelType = bindingSource.GetEnumerableElementType() Where dataBinding.DataSource is BindingSource Private static void AddDataAnnotationsValidations(Control control,įrom dataBinding in () Let view = (DataView)bindingSource.SyncRoot ![]() Let bindingSource = (BindingSource)dataBinding.DataSource Private static void AddMaximumStringLengthToDataViewBoundTextBox(Control control)įrom dataBinding in () Private static void RegisterBindingSourceValidationsForControl(Ĭontrol control, ErrorProvider errorProvider)ĪddMaximumStringLengthToDataViewBoundTextBox(control) ĪddDataAnnotationsValidations(control, errorProvider) RegisterBindingSourceValidationsRecursive(childControl, provider) RegisterBindingSourceValidationsForControl(childControl, provider) ![]() Private static void RegisterBindingSourceValidationsRecursive(įoreach (Control childControl in control.Controls) RegisterBindingSourceValidationsRecursive(form, errorProvider) Requires.IsNotNull(errorProvider, "errorProvider") public static void RegisterBindingSourceValidations(Form form, With this information the validation can be hooked. The trick is to look at the control's DataBindings to determine the type and property that the control is bound to. So my question is: how do I enable validation in WinForms (using the ErrorProvider) but without having to implement IDataErrorInfo on the classes that I use to bind?įor instance, is there a way to hook onto the ErrorProvider and delegate the validation of to DataAnnotations' Validate class? The only thing I want to do is mark my command properties with DataAnnotation attributes. Since commands are part of the domain, I don't want to implement IDataErrorInfo on them, because this would couple them directly with the validation logic (since calling one of the IDataErrorInfo methods assumes validation). Commands are DTOs that describe the business operation and are defined in the domain layer (the logic for executing those commands is defined in the business layer). I often can bind my command objects to the interface. Validation in WinForms however seems to work around the IDataErrorInfo interface, but I don't like to implement this interface on the objects I use for binding. I'm working on an (legacy) WinForms application and I like to do a more dynamic way of supplying the users with error information in a way I'm used to do with MVC. ![]()
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