One databinding prevents other from working

Question

I have a textblock that is a 'status label'. I want this label to be updated, and when that happens, I want its color to be also set automatically - as well as visibility (Label invisible until it has content).

The problem is, that if I specify anything more than the text binding, then the textblock does not change (i.e. text does not appear, and it is still hidden). Actually, I tried also without binding visibility, and it appears that the Foreground also blocks the binding.

<TextBlock x:Name="StatusInfo"
                               HorizontalAlignment="Center" VerticalAlignment="Bottom"
                               FontSize="9"
                               Visibility="{Binding ElementName=ThisUc,
                                                    Path=StatusLabelVisibility}"
                               Text="{Binding ElementName=ThisUc,
                                              Path=StatusLabel}"
                               Foreground="{Binding ElementName=ThisUc,
                                                    Path=StatusLabelBrush}" />

This is all in a UserControl, so I am using dependency properties for StatusLabel property, as I want to bind it to properties in main window... Foreground and Visibility properties are not dependency properties, as I don't want to expose them. This is my property setter and getter:

public string StatusLabel
        {
            get { return (string)GetValue(StatusLabelProperty); }
            set
            {
                SetValue(StatusLabelProperty, value);
                RaisePropertyChanged("StatusLabel");
                if (value != string.Empty)
                {
                    StatusLabelVisibility = System.Windows.Visibility.Visible;
                    if (value.HasAny("success", "ok") && !value.HasAny("partial"))
                    {
                        StatusLabelBrush = Brushes.Green;
                    }
                    else if (value.HasAny("fail"))
                    {
                        StatusLabelBrush = Brushes.DarkRed;
                    }
                    else if (value.HasAny("partial"))
                    {
                        StatusLabelBrush = Brushes.DarkGoldenrod;
                    }
                    else
                    {
                        StatusLabelBrush = Brushes.Black;
                    }
                }
                else
                {
                    StatusLabelVisibility = System.Windows.Visibility.Collapsed;
                }
            }
        }

Please let me know what am I doing wrong, perhaps that's not the way to go altogether?

Cheers

====================

While Meredith's answer solved the issue, let me just post a comment for future reference (as it was not obvious for me):

Here it goes - if you assign the UserControl property directly, not via property binding, it appears to lose the 'bound' - and if you try to change the bound property again, it won't update the control as it would have before it 'lost the bound'

Cheers

Have you tried changing the order of the properties you are specifying ? — Abin, Jul 15 '15 at 19:36
@Abin - Yes, I have - as well as changing the order of statements in property setter. That didn't help - and actually, I want to understand what the principle is. — Bartosz, Jul 15 '15 at 20:19

score 3 · Accepted Answer · edited May 23 '17 at 11:43

3

If StatusLabel is a DependencyProperty, you can't put anything else in the setter - it won't get called correctly. Look up the way to do changed events for DependencyProperties instead. You need a PropertyChangedCallback. Check out How to use PropertyChangedCallBack. Raise your prop changes, and set all the other properties in the callback.

edited May 23 '17 at 11:43

Community

1
1

answered Jul 15 '15 at 21:13

Meredith

173
1
7

Hi - thank you, that solved the issue - I also have a little comment on a related issue which was a bit puzzling. Here it goes - if you assign the UserControl property directly, not via property binding, it appears to lose the 'bound' - and if you try to change the bound property again, it won't update the control as it would have before it 'lost the bound' – Bartosz Jul 17 '15 at 11:07
Yes - if you directly assign the value, it will in fact lose the binding. You need to assign only via binding. – Meredith Jul 30 '15 at 21:06

One databinding prevents other from working

1 Answers1