How to access stackpanel user control to user control in WPF C#?

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A stack panel allows access from one user control to another user control but does not allow access to children of the stack panel.Rows that I add from the power_setting usercontrol inside the stackpanel won't let me access them from the Print_Setting usercontrol.From stackpanel power_setting is in UserControl

What I have tried:

this is my code for power_setting(User Control):-

C#

private void addbtn_Click(object sender, RoutedEventArgs e)
        {
            AddNewRow();
            rowCounter++;
        }
        private void AddNewRow()
        {
            var newRow = CreateRow();
            RowsStackPanel.Children.Add(newRow);
        }
        private StackPanel CreateRow()
        {
            var row = new StackPanel { Orientation = Orientation.Horizontal };
            var textBox1 = new TextBox { HorizontalAlignment = HorizontalAlignment.Left, Height = 23, Width = 70, Margin = new Thickness(1, 5, 5, 5), TextWrapping = TextWrapping.Wrap };
           
           
            // Event handler for textBox1 TextChanged event
            textBox1.TextChanged += (sender, e) =>
            {
                // Get the textbox control
                TextBox textbox = (TextBox)sender;
                // Check if the textbox name contains an underscore
                if (textbox.Name.Contains("_"))
                {
                    // Split the textbox name to extract the unique identifier
                    string uniqueId = textbox.Name.Split('_')[1];
                    // Store the textbox data in the registry
                    mr.Write("moveXtxt_" + uniqueId, textbox.Text);
                }
            };
            row.Children.Add(textBox1);
            return row;
        }

this is my code for Print_Setting usercontrol):-

C#

private void PrintPowersetbtn_Click(object sender, RoutedEventArgs e)
        {

            //powersetting.OnButton2Clicked();
            //MessageBox.Show("OK");
            CompareValuesWithPowerText();
        }

        public void CompareValuesWithPowerText()
        {
            int targetValue = int.Parse(STL.valpower);
            var selectedRows = FindRowsWithMatchingValue(targetValue);
        }

        private List<StackPanel> FindRowsWithMatchingValue(int targetValue)
        {
            Power_Setting powersetting = new Power_Setting();
            var selectedRows = new List<StackPanel>();
            StackPanel closestLowerRow = null;
            StackPanel closestHigherRow = null;
            int closestLowerDiff = int.MaxValue;
            int closestHigherDiff = int.MaxValue;

            foreach (var child in powersetting.RowsStackPanel.Children)
            {
               // code 
            }

            if (closestLowerRow != null)
            {
                selectedRows.Add(closestLowerRow);
            }

            if (closestHigherRow != null)
            {
                selectedRows.Add(closestHigherRow);
            }

            return selectedRows;
        }

Posted 14-Jun-23 2:28am

Ridhdhi Vaghani

Updated 14-Jun-23 3:07am

v3

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Comments

Graeme_Grant 14-Jun-23 8:32am

The StackPanel control is a control collection layout control, it has no rows or columns, only display orientation - horizontal or vertical.

What are you wanting exactly?

Ridhdhi Vaghani 14-Jun-23 8:37am

I want to access the children inside the stackpanel from the power_settings usercontrol to the print_settings usercontrol. please help me.

Graeme_Grant 14-Jun-23 8:43am

You need a shared context. This can be done with a static class that both user controls have access to.

Ridhdhi Vaghani 14-Jun-23 8:44am

Please give me some solution

Graeme_Grant 14-Jun-23 8:47am

I am putting together an example. You will need to implement in your project.

Ridhdhi Vaghani 14-Jun-23 8:50am

OK

Dave Kreskowiak 14-Jun-23 9:31am

That's a bad idea. Controls should not know anything about each other, nor should they even care.

The entire point behind WPF/MVVM is the controls are there to show you what is in a data model and allow you to edit that data. You seem to be under the impression that the controls should hold the data themselves. That's a bad path to go down and lead you to doing bad things like what you're trying to do in your question.

Graeme_Grant 14-Jun-23 9:42am

Totally agree. However, this guy is not using MVVM or DI, so I used an old technique to do what he is asking.

Dave Kreskowiak 14-Jun-23 10:00am

A stack panel allows access from one user control to another user control but ...

The StackPanel doesn't allow or deny access to a damn thing. It's simply a layout container to manipulate the positioning and size of controls on screen. That's all it does. There's no "allow" this or that involved.

[no name] 14-Jun-23 13:10pm

When you add to the .Children collection, also add to a public "shadow" collection in that class. That way you can share without having to access the "visual tree". Add a public static (".Current") to Power_Settings that references itself for a singleton; then: Power_Settings.Current.MyList, etc.

Graeme_Grant 14-Jun-23 20:09pm

Already answered. Your suggestion is overkill. The issue with your solution is that the second UserControl needs to understand the first's data. This is too tightly bound.

My solution has a cleaner implementation. I expose a find function in a shared singleton class that returns a result. That way there is a separation of concerns and neither needs to know about the other, only the find method in the shared class. The implementation of the find method is then contained with the data. If the 2nd UserControl needs input into the filtering, then the find method, or another find method, can include a Predicate parameter.

If the data or types change, or the first UserControl is switched out with another, the 2nd UserControl is blissfully unaware. With your solution, code breaks and changes to both UserControls is required due to the tight coupling.

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Graeme_Grant · Answer 1 · 2023-06-14T03:07:00

Create a new WPF project.

Add the following class:

C#

internal static class PowerSettingsContext
{
    public static Func<string, string> Find { get; set; }
}

This class will hold a delegate reference to the method in the UserControl that contains the StackPanel with the controls to search.

Here is that UserControl:

XML

<UserControl x:Class="WpfSharedContext.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WpfSharedContext"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
    <Grid>
        <StackPanel x:Name="MyStackPanel" Orientation="Vertical">
            <TextBlock x:Name="TextBlock1"  Text="John"/>
            <TextBlock x:Name="TextBlock2"  Text="Paul"/>
            <TextBlock x:Name="TextBlock3"  Text="George"/>
            <TextBlock x:Name="TextBlock4"  Text="Ringo"/>
        </StackPanel>
    </Grid>
</UserControl>

And the code-behind:

C#

public partial class UserControl1 : UserControl
{
    public UserControl1()
    {
        InitializeComponent();
        PowerSettingsContext.Find = FindControl;
    }

    public string FindControl(string text)
    {
        foreach (TextBlock child in MyStackPanel.Children.Cast<TextBlock>())
        {
            if (child.Text.Equals(text,
                    StringComparison.InvariantCultureIgnoreCase))
                return child.Name;
        }
        return "";
    }
}

The constructor points the shared PowerSettingsContext.Find method to the search method in the UserControl:

C#

PowerSettingsContext.Find = FindControl;

Now we can add the UserControl that will request the information:

XML

<UserControl x:Class="WpfSharedContext.UserControl2"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WpfSharedContext"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>

        <StackPanel Margin="10"
                    Orientation="Horizontal"
                    Height="40">
            <TextBlock Text="Enter Value:"
                       VerticalAlignment="Center"/>
            <TextBox x:Name="SearchText" Width="100" Margin="10 0"/>
            <Button x:Name="SearchButton"
                    Padding="20 10" 
                    Content="GO!"
                    Click="SearchButton_OnClick"/>
        </StackPanel>

        <StackPanel Grid.Row="1" Margin="10" Orientation="Horizontal">
            <TextBlock Text="Result:"/>
            <TextBlock x:Name="Result" Width="100" Margin="10 0 0 0"/>
        </StackPanel>
    </Grid>
</UserControl>

and the code-behind:

C#

public partial class UserControl2 : UserControl
{
    public UserControl2()
    {
        InitializeComponent();
    }

    private void SearchButton_OnClick(object sender, RoutedEventArgs e)
    {
        Result.Text = PowerSettingsContext.Find(SearchText.Text);
    }
}

The Search Button Click will call the shared PowerSettingsContext.Find method and display the result. Here I am looking for the text and returning the control name that has the exact match.

Now we can add both UserControls to our host (window):

XML

<Grid Margin="20">
    <Grid.RowDefinitions>
        <RowDefinition/>
        <RowDefinition/>
    </Grid.RowDefinitions>
    <local:UserControl1 />
    <local:UserControl2 Grid.Row="1" />
</Grid>

Now if you use any of the 4 names from UserControl1`, UserControl2 will show the control name that contains that text. Neither UserControl knows about the other, only the shared PowerSettingsContext class.

How to access stackpanel user control to user control in WPF C#?

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How to access stackpanel user control to user control in WPF C#?

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