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Databound RadiobuttonsI have two databound radiobuttons which have advanced databinding properties of onpropertychanged enabled so that I can raise the columnchanged event whenever the radiobuttons are changed. In the columnchanged event I am simply accepting changes into the dataset. There is no dataadapter because it is a standalone dataset. When one radiobutton is already checked (as opposed to neither) and I select the non-checked radiobutton, the columnchanged event is raised twice and erases the checked value of both radiobuttons in the acceptchanges call. It is raised twice because it is first raised to un-check the first radio button, and then called again to check the second radio button... but on the second call it somehow sees that the second radio button is not physically checked yet, so sends a false value. This is pretty simple to reproduce and funnily enough nothing seems to be available on the net to explain this with radiobuttons. Troy Probably to explain a little better:
You have Radiobutton #1 and Radiobutton #2. If #1 is checked and you click #2, firstly the two radiobuttons physically swap the checked status and are visibly correct. Then the columnchanged event is raised for the dataset. The event is firstly handled for #1 and acceptchanges is called... this causes the new false value for #1 to be saved, *and* for the existing false value for #2 (still false on the datarow), triggering the stored value and the checked value for #2 to be changed to false. This triggers the columnchanged event again and simply places false values into the radiobutton databound columns with acceptchanges. Is there any way to break that cycle? Troy Show quoteHide quote "news.microsoft.com" <troy@NO-SPAMebswift.com> wrote in message news:%237cbQeaQGHA.4900@TK2MSFTNGP09.phx.gbl... > Hello, > > I have two databound radiobuttons which have advanced databinding > properties of onpropertychanged enabled so that I can raise the > columnchanged event whenever the radiobuttons are changed. > > In the columnchanged event I am simply accepting changes into the dataset. > There is no dataadapter because it is a standalone dataset. > > When one radiobutton is already checked (as opposed to neither) and I > select the non-checked radiobutton, the columnchanged event is raised > twice and erases the checked value of both radiobuttons in the > acceptchanges call. It is raised twice because it is first raised to > un-check the first radio button, and then called again to check the second > radio button... but on the second call it somehow sees that the second > radio button is not physically checked yet, so sends a false value. > > This is pretty simple to reproduce and funnily enough nothing seems to be > available on the net to explain this with radiobuttons. > > > Troy > > Hi,
http://msdn.microsoft.com/msdnmag/issues/04/07/AdvancedBasics/ Ken ------------- Show quoteHide quote "news.microsoft.com" <troy@NO-SPAMebswift.com> wrote in message news:%237cbQeaQGHA.4900@TK2MSFTNGP09.phx.gbl... > Hello, > > I have two databound radiobuttons which have advanced databinding > properties of onpropertychanged enabled so that I can raise the > columnchanged event whenever the radiobuttons are changed. > > In the columnchanged event I am simply accepting changes into the dataset. > There is no dataadapter because it is a standalone dataset. > > When one radiobutton is already checked (as opposed to neither) and I > select the non-checked radiobutton, the columnchanged event is raised > twice and erases the checked value of both radiobuttons in the > acceptchanges call. It is raised twice because it is first raised to > un-check the first radio button, and then called again to check the second > radio button... but on the second call it somehow sees that the second > radio button is not physically checked yet, so sends a false value. > > This is pretty simple to reproduce and funnily enough nothing seems to be > available on the net to explain this with radiobuttons. > > > Troy > > Thanks Ken, just curious if there is a known workaround without using a
custom control? I've got separate columns in the dataset for each radiobutton... rather than the scenario of one column and separate values for each radiobutton; it's a matter of semantics really, especially when only dealing with only a couple of paired groups of radiobuttons. I wanted to try and keep the solution simple and have no control-initiated events to update the dataset outside of the databindings setting. I have seen the custom control solution before, but I'm thinking that there has to be a far simpler answer. I think the biggest hurdle is getting around the dataset's acceptchanges overriding the newly checked radiobutton with the old dataset contents, sparking the change to be lost. Troy Show quoteHide quote "Ken Tucker [MVP]" <vb***@bellsouth.net> wrote in message news:Oti1oXdQGHA.4084@TK2MSFTNGP10.phx.gbl... > Hi, > > http://msdn.microsoft.com/msdnmag/issues/04/07/AdvancedBasics/ > > Ken > ------------- > "news.microsoft.com" <troy@NO-SPAMebswift.com> wrote in message > news:%237cbQeaQGHA.4900@TK2MSFTNGP09.phx.gbl... >> Hello, >> >> I have two databound radiobuttons which have advanced databinding >> properties of onpropertychanged enabled so that I can raise the >> columnchanged event whenever the radiobuttons are changed. >> >> In the columnchanged event I am simply accepting changes into the >> dataset. There is no dataadapter because it is a standalone dataset. >> >> When one radiobutton is already checked (as opposed to neither) and I >> select the non-checked radiobutton, the columnchanged event is raised >> twice and erases the checked value of both radiobuttons in the >> acceptchanges call. It is raised twice because it is first raised to >> un-check the first radio button, and then called again to check the >> second radio button... but on the second call it somehow sees that the >> second radio button is not physically checked yet, so sends a false >> value. >> >> This is pretty simple to reproduce and funnily enough nothing seems to be >> available on the net to explain this with radiobuttons. >> >> >> Troy >> >> > > I figured out a simple hack. At this stage I think it will only work with a
two radiobutton group. Here's the hack: Create the two radiobutton group and databind them to two separate table values. Setup the databindings checked event for each radiobutton, and under advanced, change the event type to onpropertychanged. If you run the project now, you will see the problem reproduced, where it actually takes two clicks to change to a new radiobutton value. To fix this, in ONE of the radiobutton column definitions, change the expression to 'Not otherradiocolumn', where otherradiocolumn is the name of the table column for the OTHER radiobutton. This will ensure that the radiobuttons always switch and never cancel one another out. If this solution could be expanded to three or more radiobuttons it would remove the need for messy usercontrols, though I'm not sure it would be possible. Troy Show quoteHide quote "news.microsoft.com" <troy@NO-SPAMebswift.com> wrote in message news:%237cbQeaQGHA.4900@TK2MSFTNGP09.phx.gbl... > Hello, > > I have two databound radiobuttons which have advanced databinding > properties of onpropertychanged enabled so that I can raise the > columnchanged event whenever the radiobuttons are changed. > > In the columnchanged event I am simply accepting changes into the dataset. > There is no dataadapter because it is a standalone dataset. > > When one radiobutton is already checked (as opposed to neither) and I > select the non-checked radiobutton, the columnchanged event is raised > twice and erases the checked value of both radiobuttons in the > acceptchanges call. It is raised twice because it is first raised to > un-check the first radio button, and then called again to check the second > radio button... but on the second call it somehow sees that the second > radio button is not physically checked yet, so sends a false value. > > This is pretty simple to reproduce and funnily enough nothing seems to be > available on the net to explain this with radiobuttons. > > > Troy > > 
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