c sharp uniform blink errorprovider blink

C sharp uniform blink errorprovider blink how to#
C sharp uniform blink errorprovider blink code#

The KeyPress event fires only if the key that ispressed generates a character value. Returns the character value that corresponds to the key Indicates whether the event has been handled Table 3.4 Important Members of the KeyPressEventArgs Class Table 3.4 lists the properties of KeyPressEventArgs. Its event handler receives an argument of type KeyPressEventArgs. The KeyPress event happens after the KeyDown event butbefore the KeyUp event. You choose the event to program based on the orderin which the event is fired and the information that is passed in the eventargument of the event handler. You can program the event handlers for these events in order to performkeystroke-level validation. When you press a key on a control, three events take place, in the followingorder: The first technique is discussed relative to the use of various controls inChapter 2, 'Controls' the following sections cover rest of thesetechniques. You can analyze the contents of the data field as a whole and warn theuser of any incorrect values when he or she attempts to leave the field or closethe window. You can restrict entry in some data fields by enabling or disabling them,depending on the state of other fields.

You can capture the user's keystrokes and analyze them for validity.Some fields may require the user to enter only alphabetic values but no numericvalues or special characters in that case, you can accept the keystrokes foralphabetic characters while rejecting others. Theseallow users to select from a set of given values rather than permit freekeyboard entry. You can restrict the values that a field can accept by using standardcontrols such as combo boxes, list boxes, radio buttons, and check boxes. You can use various techniques for validatingdata: The most relevant place to ensure the validity of data is at thetime of data entry itself. When designing an application that acceptsdata from the user, you must ensure that the entered data is acceptable for theapplication.

C sharp uniform blink errorprovider blink how to#

As for the custom ErrorProvider that I have been wanting to do, I've learned a lot about how to do it, so the exercise has not been in vain.MCAD/MCSD Training Guide (70-316): Developing and Implementing Windows-Based Applications with Visual C# and Visual Studio.NET The price of the 'feature' isn't worth the price of admission. It's certainly not impossible, but I am now of the opinion that if you want to syncronize the blinking of error icons, your best bet is to change your mind. The whole BindToObject and the internal methods that support it are highly useful and IMO should not have been marked internal.

C sharp uniform blink errorprovider blink code#

And if we didn't want to lose the data binding ability, that whole thing would have to be re-written (due to the internal code), and I don't even know if it's possible to read Bindings the way that all the internal code does. And besides, who uses the control mirroring ability in WinForms? I mean really, use WPF for that kind of thing! We might avoid all the p/invoke and NativeWindow stuff by replacing it with a PictureBox, a little heavier, but how many controls do you have on your form anyhow? Even after cutting the fat, the amount of work involved is very high. Let's get rid of it too, after all the default icon on the error provider is semetrical, it looks the same whether it's mirrored or not. But then there's this 'mirror DC' thing that again uses several internal types (mainly ). Lots of p/invoke here, more copy/pasting. So what if we just cut out all of the data binding ability? You didn't need it right? That leaves us with the NativeWindow implementation used to display the icon. Almost all of that code is found in the data binding ability of the ErrorProvider (I didn't even know ErrorProvider could work off of a DataSet all automagically like that). This thing uses a ton of internal types and internal methods on public types. At first I figured I could just do a copy/paste job from Reflector and modify the timer bits.

Let me rephrase the statement: The only other thing I can think of is to do your own ErrorProvider, but I looked into this for someone else, and the amount of work involved is staggering. I'm re-quoting Deborah's statement to point out that it is a gross understatement. But I looked into this for someone else, and it does not appear to be very easy to do. The only other thing I can think of is to do your own ErrorProvider.