Net textbox validating
So I am having a form with 2 textboxes,which allow only numeric data & if the data is Non-numeric it will prompt with a messagebox. Have a look at MSDN Help: Text Box -- Events and Control.
One way would be to put something like If textbox1.text="" then textbox1="0" as the first line of code in your validating event. Text Changed is fired every time characted is changed, deleted or added. You are required to decide for yourself whether or not it is suitable for your purposes and no liability for loss of any nature can be entertained.
Where do these validation error messages come from?
Figure 04: Prebinding Validation Errors(Click to view full-size image) There are actually two types of validation error messages - those generated before the HTML form fields are bound to a class and those generated after the form fields are bound to the class.
Controls that helps creating custom validation rules for user input.
Having defined Validation Rule as above if user input is invalid, Text Box will have a red border.
If you submit the HTML form for creating a Product, and you enter an invalid value for the price field and no value for the Units In Stock field, then you'll get the validation messages displayed in Figure 4.The page in Figure 3 illustrates the error messages rendered by the validation helpers when the form is submitted with missing fields and invalid values.Figure 03: The Create view submitted with problems (Click to view full-size image) Notice that the appearance of the HTML input fields are also modified when there is a validation error. Text Box() helper renders a attribute when there is a validation error associated with the property rendered by the Html. There are three cascading style sheet classes used to control the appearance of validation errors: The Html Helper class includes read-only static properties for retrieving the names of the validation related CSS classes.You learn how to use model state and the validation HTML helpers.You use model state - or more accurately, the model state dictionary - to represent validation errors. Add Model Error("Description", "Description is required."); if (product To Create.