Check string in textbox with an event? - c#

I'm wondering if there is a way to use an event to check a string in a textBox in a windows form before the user clicks on the OK button?

You can use the KeyDown, KeyPress, or KeyUp event.
A full list of events can be found here: http://msdn.microsoft.com/en-us/library/system.windows.forms.textbox_events.aspx
It's all alphabetical, so scroll down to Key....

A better approach is to use the Validating event of the textbox. This way, your validation routine runs when the user attempts to leave the textbox.

Related

Can I fire an Event when I tab out of a textbox without entering a value?

I have an ASP.NET Webform (C#) that has a textbox on it. I would like to know if there is a way to fire an event when the user tabs off the textbox without entering a value?
I set Autopostback=True and CauseValidation=true. If i enter anything in the textbox it fires the TextChanged event which is fine. But if they tab without entering anything nothing happens.
Any Ideas?
thank you
You csn handle Lost focus event on client side (js), then cause postback or run ajax request if you need server side code.
There is an event called OnBlur in which you can use when the user doesn't enter any value.
Textbox OnBlur event fires when user leaves the textbox.
Use something like this.
in OnBlur add a javascript function as per your requirement.

Event for "end edit" in a text box

I am using a textbox in winform (c#) and using the text to make consults in a database.
But I need constantly consult the text of the textbox every time that text changes. So for these, I use the KeyUp. But this event is too slow.
Is any event that just fires when the textbox editing has been finished ?. I consider for finish 2 conditions
The control lost focus.
The control has 200ms without keypress
You could use the LostFocus event, to capture when the user clicks on a control outside the textbox.
Otherwise, you'll need to choose from one of the existing events. (Listed here)
Come to think of it, you will likely have to capture multiple events. DragDrop if someone copies/pastes, for example...
You mean something like this?
Control.LostFocus
Provided that you consider finished as being when they click off the textbox.

WinForms ComboBox - Event when Text Input is Clicked Into

I have a feature request that when a ComboBox is 'clicked into' that it clears the text so that the user can start entering in new data to search. Does anyone know of a way to hook into this? The 'click' event is raised on when the text is clicked as well as when the drop down arrow is also clicked (which opens up the drop down with items). I only want it to happen on the first, not the latter.
Right now I'm capturing the click event and filtering on the DroppedDown property like so:
if(!comboBox.DroppedDown)
{
// clear selection
}
This seems to work most of the time, but bugs out frequently as well... so its not 100%.
If anyone knows of a proper way to do this I would appreciate!
Don't handle the click event. For one thing, it won't fire if the user tabs the focus into the control. Use the Enter event which fires when the control receives focus. And rather than clearing text you should just select it all which will give the best of both worlds:
1) The user can start entering new text which will clear any old text or
2) tab past the control and leave the contained text as it was.
If you always remove the previous text you may anger users.
Try the "Enter" event. It happens when a control gains focus on the form.

C# / Filter input of a textbox and display notification balloon

I'm wondering how to filter the input of a .NET textbox.
I already know that I could listen for the KeyDown event and intercept the key, but that won't filter pasted strings by a right-click menu or a CTRL+V.
I also don't wan't to completely disable the possibility of pasting of characters in the textbox. The paste action should be cancelled whenever it contains one or more invalid characters.
Finally, I'd like to display a notification balloon whenever invalid characters are either entered or pasted.
μTorrent already has this exact behavior:
How can I achieve this functionality in C# ?
TextChanged event - Seems like a good call.
You can spawn your own baloon or ToolTip on any control you want to show a detailed feedback to the user
It seems like a combination of KeyPress, TextChanged, Validating, and Validated events should work for your purposes.

Delay Keypress until TextBox is enabled

My custom Control displays a TextBox when a key is pressed (basically to allow for numeric input). It's easy enough to show the TextBox from inside the KeyDown event on the main control, but how do I pump the keypress into the textbox?
Why dont you keep a buffer ( a variable) to store the value of KeyPress and after the TextBox is Enabled, update the value?
You can use the KeyValue of the KeyEventArgs parameter (sent to the method handling the keydown event of your user control).
Using that you can send the first key to the textbox and then move the focus to the textbox like suggested before.
Hope I understood you well.

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