Errorprovider vb.net icon placement how to#
Errorprovider vb.net icon placement code#

Hovering the mouse over the error icon will tell you what is wrong and how to fix it. You will find as you tab through the textboxes on the form, that you will get the error icon appearing unless you enter data in the right format. I have attached a sample project written in C#, which has a typical (though simplified) data entry form for some customer information. You could have one with a yellow icon rather than red, for when a field is valid but could be better. You can have as many error providers on a form as you wish, but I can only see a potential use for two. Private void txtTown_Validating(object sender, It's up to you how you do your validation, it could be as simple as text length constraints or as advanced as regular expressions matching.

Errorprovider vb.net icon placement code#

Now, in the Validating event of the textbox you need to put the code to test the contents for validity and optionally display the error icon. Put an ErrorProvider in your component tray too. Using it on a formĬreate yourself a form, with a textbox on it. While this may sound trivial, it's actually rather useful. When the user hovers their mouse over this icon a tooltip is instantly displayed with information about the invalid field. What this component can do is display a little red icon beside any control which is invalid. It is a component rather than a control, so when you put it on your form it will sit in the component tray below. This little Gem is often left unnoticed, which is a funny thing considering it sits in the Windows Forms Controls Toolbox by default. So what we need is a method of unobtrusively showing that data is invalid, and presenting it in such a way that it is immediately obvious what is wrong and what to do about it. Also, we don't want all the validation done when the user presses the OK button, because they could then potentially be given a great big message with all the fields that are wrong.

That would be an unnecessary interruption. The last thing we need is for a Message Box to pop up when we tab away from a field, telling us it's invalid. When we do get it wrong, however, we don't want to be bugged about it. When a user is tabbing fast through a dialog entering data, they are sometimes going to get it wrong. Built-in validation doesn't go much further than an enforcable maximum length for textboxes, but there are some nice methods you can use to make validation a breeze. Run the application, click the button, the red icon will be shown on right side of TextBox, move the mouse onto the icon, the tooltip 'Error' will be displayed, wait until the blink stoped, click on the red icon, then you will find the tooltip disappeared. Data input validation in Windows Forms is essential.