WPF C# Looping through Tab Control looking for Textboxes

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1.44/5 (2 votes)

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Hello, I have a problem. I need to return data from SQL into a Window to fill in textboxes. If a textbox is empty post return, then turn the background color == red.

I got it to work using the code below:

C#

private void PlayingWithColors()
{
    foreach (var tb in FindVisualChildren<TextBox>(this).Where(tb => tb.Text == String.Empty))
    {
        tb.Background = Brushes.Red;
    }
}

public static IEnumerable<T> FindVisualChildren<T>(DependencyObject depObj) where T : DependencyObject
{
    if (depObj == null) yield break;
    for (var i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
    {
        var child = VisualTreeHelper.GetChild(depObj, i);
        var children = child as T;
        if (children != null)
        {
            yield return children;
        }

        foreach (var childOfChild in FindVisualChildren<T>(child))
        {
            yield return childOfChild;
        }
    }
}

The problem is the end users. They now want a smaller window and tabs. So as soon as I added the tabcontrol, I lost the functionality. What am I doing wrong or what can I do differently to read through the tabs for all textboxes?

Example XAML:

C#

<TabItem Header="Vitals">
                <GroupBox Header="Vital Signs" FontWeight="Bold" BorderBrush="Black" BorderThickness="1"
                          Margin="10">
                    <StackPanel Margin="10" HorizontalAlignment="Left" Width="782">
                        <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Width="171"
                                   Margin="1,1,1,0"
                                   UseLayoutRounding="True" Height="30">
                            <Label Content="HR:                " FontWeight="Normal"
                                   HorizontalAlignment="Left" VerticalContentAlignment="Center"
                                   Height="27" />
                            <TextBox x:Name="TbHr" TextWrapping="Wrap" Text="" HorizontalAlignment="Center"
                                     Width="75" VerticalContentAlignment="Center"
                                     HorizontalContentAlignment="Left" Height="27" />
                        </TextBlock>
                        <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Width="171"
                                   Margin="1,1,1,0"
                                   UseLayoutRounding="True" Height="30">
                            <Label Content="RR:                 " FontWeight="Normal"
                                   HorizontalAlignment="Left" VerticalContentAlignment="Center"
                                   Height="27" />
                            <TextBox x:Name="TbRr" TextWrapping="Wrap" Text="" HorizontalAlignment="Center"
                                     Width="75" VerticalContentAlignment="Center"
                                     HorizontalContentAlignment="Left" Height="27" />
                        </TextBlock>
                        <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Width="171"
                                   Margin="1,1,1,0"
                                   UseLayoutRounding="True" Height="30">
                            <Label Content="BP:                 " FontWeight="Normal"
                                   HorizontalAlignment="Left" VerticalContentAlignment="Center"
                                   Height="27" />
                            <TextBox x:Name="TbBp" TextWrapping="Wrap" Text="" HorizontalAlignment="Center"
                                     Width="75" VerticalContentAlignment="Center"
                                     HorizontalContentAlignment="Left" Height="27" />
                        </TextBlock>
                        <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Width="171"
                                   Margin="1,1,1,0"
                                   UseLayoutRounding="True" Height="30">
                            <Label Content="Weight:          " FontWeight="Normal"
                                   HorizontalAlignment="Left" VerticalContentAlignment="Center"
                                   Height="27" />
                            <TextBox x:Name="TbWgt" TextWrapping="Wrap" Text=""
                                     HorizontalAlignment="Center"
                                     Width="75" VerticalContentAlignment="Center"
                                     HorizontalContentAlignment="Left" Height="27" />
                        </TextBlock>
                        <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Width="171"
                                   Margin="1,1,1,0"
                                   UseLayoutRounding="True" Height="30">
                            <Label Content="Weight Type: " FontWeight="Normal"
                                   HorizontalAlignment="Left" VerticalContentAlignment="Center"
                                   Height="27" ToolTip="lb or kg" />
                            <TextBox x:Name="TbWgtType" TextWrapping="Wrap" Text=""
                                     HorizontalAlignment="Center"
                                     Width="75" VerticalContentAlignment="Center"
                                     HorizontalContentAlignment="Left" Height="27" />
                        </TextBlock>
                        <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Width="181"
                                   Margin="1,1,1,0"
                                   UseLayoutRounding="True" Height="30">
                            <Label Content="Vital Date:      " FontWeight="Normal"
                                   HorizontalAlignment="Left" VerticalContentAlignment="Center"
                                   Height="27" ToolTip="lb or kg" />
                            <TextBox x:Name="TbVitalDate" TextWrapping="Wrap" Text=""
                                     HorizontalAlignment="Center"
                                     Width="87" VerticalContentAlignment="Center"
                                     HorizontalContentAlignment="Left" Height="27" />
                        </TextBlock>
                    </StackPanel>
                </GroupBox>
            </TabItem>

Posted 18-Jul-15 14:21pm

Derek Kennard

Updated 6-Nov-17 8:06am

v2

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2 solutions

Solution 2

Based on the above solution, I tweaked the code so you can pas in a WPF window with tab controls or other containers, and it will loop through all the textbox controls. The TB controls are added to a visual items list and with the returned list you can do whatever you like.

Remove the where clause to remove the restriction for only empty textboxes. Don't forget to close the bracket after (parent) )

Remove this ==> .Where(tb => tb.Text == String.Empty))

<pre>public class cEnumControls
    {
        public static List<Visual> EnumVisual(UIElement Parent, List<Visual> collection)
        {
            foreach (var tb in FindVisualChildren<TextBox>(Parent).Where(tb => tb.Text == String.Empty))
            {
                collection.Add((Visual)tb);
                //tb.Background = Brushes.Red;
            }
            return collection;
        }


        public static IEnumerable<T> FindVisualChildren<T>(DependencyObject obj) where T : DependencyObject
        {
            if (obj != null)
            {
                if (obj is T)
                    yield return obj as T;

                foreach (DependencyObject child in LogicalTreeHelper.GetChildren(obj).OfType<DependencyObject>())
                    foreach (T c in FindVisualChildren<T>(child))
                        yield return c;
            }
        }
    }

Posted 6-Nov-17 8:06am

Member 2796559

Updated 6-Nov-17 8:38am

v2

Comments

Richard Deeming 6-Nov-17 15:50pm

This question was solved over TWO YEARS ago. And your solution doesn't really add anything to the accepted solution - it even copies the FindVisualChildren method verbatim!

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Mahindra Shambharkar · Accepted Answer · 2015-07-19T02:22:00

Issue is with iterating over Visual Tree to find control. If you debug your application you can see that TextBox Control that is present different tabitem than current is not visible and hence not shown in Visual Tree.

Just replace FindVisualChildren method with

C#

public static IEnumerable<T> FindVisualChildren<T>(DependencyObject obj) where T : DependencyObject
       {
           if (obj != null)
           {
               if (obj is T)
                   yield return obj as T;

               foreach (DependencyObject child in LogicalTreeHelper.GetChildren(obj).OfType<DependencyObject>())
                   foreach (T c in FindVisualChildren<T>(child))
                       yield return c;
           }
       }

Hope this will solve your problem.