Winform Combobox Databinding problem. Is this a bug or normal operation?

Rob Dob

Hi, I have a question. I am using the standard winform ComboBox who's text value is databound to my bindingsource. Everything seems to work correctly however, if I have the style of the combobox set to DropDownList and I change the value of the control by tabing over to it and then using the up/down arrow keys then the new value within the combobox does NOT get sent to the datasource, if however I click on the control and change the value using the mouse then the change makes it to the datasource, if I then change the property of the combobox to dropdown it seems to save the change to the datasource regardless if I tab and change the value using the up or down arrows or change it with the mouse..

Any Help would be greatly appreciated. Is this normal operation or a bug?

You can download a copy of my project from the link below: http://www.classifieds.ca/publicfiles/comboboxtest.zip

if you tab between the two combo box's and us the up/down arrow keys to change the value within the combobox and then select the save button the value never propagates itself to the datasource.

Thanks,

2 Replies

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Rob Dob17y ago
Thank you, so much, that did the trick changing the Binding Property to "SelectedItem"

Thank you..
0

Dushan Stankovic17y ago

I look at your code and debug it. When set ComboBox.DropDownStyle to DropDownList and with up/down arrow keys change selected items in cmb it is just occurs SelectedValueChanged event, but don't TextChanged event.
Look at the msdn explanation:

	Member name	Description
	Simple	The text portion is editable. The list portion is always visible.
	DropDown	The text portion is editable. The user must click the arrow button to display the list portion. This is the default style.
	DropDownList	The user cannot directly edit the text portion. The user must click the arrow button to display the list portion. The list displays only if AutoCompleteMode is Suggest or SuggestAppend.

Text portion is not EDITABLE at DropDownList Style, and when you changing values with arrow keys you just change them into drop down list. I think that you have your bug because you Bind Text property of CMB to BindingSource, and it's be better to bind SelectedValue or something like that.