Below is a simple code sample for general validation purpose. Cause Validation: True Private Sub Button Send_Click(By Val sender As System. Auto Validate: Disable or Enable Allow Focus Change Text Box. Click 'Validate Children() returns true when all child controls are validated If Me. Show("Success") End If End Sub Private Sub Text Box Not Empty_Validating( _ By Val sender As System. If not to prevent the focus change then at least for the Causes Validation property.
It allows you to specify required characters, optional characters, literal characters, such as hyphens and parentheses, currency characters, and date separators.
The control also works well when bound to a data source.
No point in validating anything when the user decides to dismiss the dialog.
I want to check what the user is writing in a textbox before I save it in a database. I guess I can always write some ifs or some try-catch blocks, but I was wondering if there's a better method.
Windows Forms provides several ways for you to validate input in your application.
If you need to require users to enter data in a well-defined format, such as a telephone number or a part number, you can accomplish this quickly and with minimal code by using the Masked Text Box control.The Format event on a data binding can be used to reformat incoming data to comply with the mask, and the Parse event can be used to reformat outgoing data to comply with the specifications of the data field. If you want full programmatic control over validation, or need to perform complex validation checks, you should use the validation events built into most Windows Forms controls.Each control that accepts free-form user input has a Validating event that will occur whenever the control requires data validation.By using validation, you can make sure that your control's data satisfies the format required by the data source, and that it does not contain any special characters such as quotation marks and back slashes that might be unsafe.When you use data binding, the data in your control is synchronized with the data source during execution of the Validating event.So, which is the better option, in terms of both efficiency and industry-standards?