Solved

WPF textbox - how to refresh associated textboxes when data changes

Posted on 2015-01-11
3
166 Views
Last Modified: 2015-01-12
Hi
I have three textboxes. one to hold a value, one to hold a percentage and one to hold the answer to a calculation using the value and percentage.
They are all bound to the current view and work correctly on initial load of data.

They are defined like this
<TextBox x:Name="AppLicPer" Grid.Row="1" Grid.Column="2" HorizontalAlignment="Left"  Margin="5" TextWrapping="Wrap" Text="{Binding Path=CurrentlyViewingApplication.AppLicPer}"
 VerticalContentAlignment="Center" TextAlignment="Right" Width="50" />

<TextBox x:Name="AppLicValue" Grid.Row="1" Grid.Column="3" HorizontalAlignment="Left"  Margin="5" TextWrapping="Wrap" Text="{Binding Path=CurrentlyViewingApplication.AppLicValue}"
 VerticalContentAlignment="Center" TextAlignment="Right" Width="50" />

<TextBox x:Name="AppAmountDue" Grid.Row="1" Grid.Column="4" HorizontalAlignment="Left"  Margin="5" TextWrapping="Wrap" Text="{Binding Path=CurrentlyViewingApplication.AppAmountDue}"
 VerticalContentAlignment="Center" TextAlignment="Right" Width="50" />

If I change either the value (AppLicValue) or the percentage (AppLicPer) how do I get the textbox that holds the  answer to refresh (AppAmountDue)?

In winform I would use an after_update event, recalc and write the answer to the textbox.

How can I achieve this in WPF?
Thanks
Andy
0
Comment
Question by:ieg
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 70

Expert Comment

by:Éric Moreau
ID: 40543410
You need to set te Mode on your data binding:

Text="{Binding Path=CurrentlyViewingApplication.AppLicValue, Mode=TwoWay}"
0
 

Author Comment

by:ieg
ID: 40544091
Hi Eric
Thanks for the comment - I use your web site regularly, great source of info

I experimented with your idea. The Mode=TwoWay seems to control the binding of the control itself and not the content of other textboxes
My problem seems to have been caused by my use of sub properties CurrentlyViewingApplication.AppLicPer
Doing this didn't give me any way of controlling what happened when the AppLicPer value changed (only when something on CurrentlyViewingApplication changed and I didn't want this area re calculating every time something changed anywhere on the record.)

So I created a method specifically for this control binding and that allowed me to do a NotifyPropertyChanged on the AppAmountDue control

public decimal? AppLicPer
        {
            get
            {
                if (_CurrentlyViewingApplication != null)
                    return _CurrentlyViewingApplication.AppLicPer;
                else return null;
            }
            set
            {
                _CurrentlyViewingApplication.AppLicPer = value.Value;
                NotifyPropertyChanged("AppAmountDue");
            }

        }

These new MVVM concepts take some getting used to when coming from a traditional winform background
Thanks for your help
0
 
LVL 70

Accepted Solution

by:
Éric Moreau earned 500 total points
ID: 40544261
have you also tried to notify the change of your AppLicPer?

NotifyPropertyChanged("AppLicPer");
NotifyPropertyChanged("AppAmountDue");
0

Featured Post

Salesforce Made Easy to Use

On-screen guidance at the moment of need enables you & your employees to focus on the core, you can now boost your adoption rates swiftly and simply with one easy tool.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In order to hide the "ugly" records selectors (triangles) in the rowheaders, here are some suggestions. Microsoft doesn't have a direct method/property to do it. You can only hide the rowheader column. First solution, the easy way The first sol…
Introduction Hi all and welcome to my first article on Experts Exchange. A while ago, someone asked me if i could do some tutorials on object oriented programming. I decided to do them on C#. Now you may ask me, why's that? Well, one of the re…
There are cases when e.g. an IT administrator wants to have full access and view into selected mailboxes on Exchange server, directly from his own email account in Outlook or Outlook Web Access. This proves useful when for example administrator want…
Add bar graphs to Access queries using Unicode block characters. Graphs appear on every record in the color you want. Give life to numbers. Hopes this gives you ideas on visualizing your data in new ways ~ Create a calculated field in a query: …

728 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question