Let's apply second approach void buttonSave_Clicked(object sender, EventArgs e)ĮrrorProvider1.SetError(txtNote, "Omg, can't haz empty note") Second one keep button Save enabled all time, but as soon as user press it, everything will be validated and if something invalid - nothing will happens.īoth approaches can use hints for the user to display what is wrong. instant, during edit, preventing user from accessing invalid commands įirst one basically monitor user input all time and keep button Save disabled until all fields are filled and values are ok.Or it will occurs when you click Cancel button, while in the middle of entering value into TextBox, which is stupid, as you just want to close stupid form ) Specifically in your case: validation will not occurs because you may click Save button without entering anything into TextBox. Why would I want to validate TextBox value on loosing focus? I want to validate it as user inputting text or at the end, when user press Ok button to check cross-dependencies of entered values. I think the whole concept of validating is crap. My question is why does my TextBox only validate when I click on it, and how can I make my "save" button check the validation of the TextBox with the ErrorProvider component? (this.txtNote_Validating) Īnd the txtNote_Validating method looks like: protected void txtNote_Validating(object sender,ĮrrorProvider1.SetError((Control)txtNote, "An explanation of your time entry is required.") Īlso, I have added no events into the properties window for my txtNote, and HAVE added a validating event: txtNote_Validating and Click: btnSave_Click to my btnSave events in the property window. This event handler code is in the btnSave_Click method: += new You might also like.I am new to WinForms and have a basic form where the user enters data to a TextBox and can press either "save" or "cancel." I wanted to implement data validation to ensure the user actually enters something into the TextBox, but as of now, the ErrorProvider icon only appears if the TextBox, itself, is clicked, and is not checking validation when the "Save" button is pressed like I was intending. 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. 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. Data input validation in Windows Forms is essential.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |