Mvvm- set control focus from flyout to parent form ?

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C#

WPF

MVVM

I am working with MVVM and i want to set the focus to textbox or button from popup window(Flyout) to parent windows using MVVM and WPF, i tried a lot, but not able to find any solution.


parent and child form is a User Control, and on a parent form there is button and when click on that button a flyout is being open and when selecting an item from that form the button should be selected or focused of parent form.


Please help

What I have tried:

Flyout code:

<Controls:MetroWindow.Flyouts>
    <Controls:FlyoutsControl>
        <Controls:Flyout Style="{StaticResource flyout}"  IsOpen="{Binding IsClassFlyoutOpen}" >
            <Views:SelectClass></Views:SelectClass>
        </Controls:Flyout>
</Controls:FlyoutsControl>
</Controls:MetroWindow.Flyouts>

parent form code is below:

<UserControl x:Class="GA.Recovery.UI.Views.Select"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:ignore="http://www.galasoft.ch/ignore" 
        xmlns:common="clr-namespace:GA.Recovery.UI.AppHelpers" 
        mc:Ignorable="d ignore"
        xmlns:Views="clr-namespace:GA.Recovery.UI.Views"
        xmlns:model="clr-namespace:GA.Recovery.UI.Model"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
        xmlns:cmd="http://www.galasoft.ch/mvvmlight"     
        DataContext="{Binding SelectViewModel, Source={StaticResource Locator}}" Loaded="UserControl_Loaded">


    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="100"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto" />
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
        </Grid.RowDefinitions>

        <Views:SelectReadOnly x:Name="selectReadOnlyView" Grid.Column="0" Grid.Row="0" Grid.RowSpan="6"  />

        <Button Focusable="True" Name="btnSelectClass" TabIndex="17" Grid.Column="1" Grid.Row="0" Content="Select" Style="{StaticResource btn-primary}" Width="90"  Margin="10,0,0,0"  VerticalAlignment="Bottom"
                Command="{Binding OpenFlyoutCommand}" CommandParameter="Class" Click="btnSelectClass_Click">
            <Button.ToolTip>
                <ToolTip Content="Select Class" Style="{StaticResource tooltip}"></ToolTip>
            </Button.ToolTip>
        </Button>

        <Button TabIndex="18" Grid.Column="2" Grid.Row="1" Content="Select" Style="{StaticResource btn-primary}" Width="90"  Margin="10 2, 0, 3" >
            <Button.ToolTip>
                <ToolTip Content="Select Sub Class" Style="{StaticResource tooltip}"></ToolTip>
            </Button.ToolTip>
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="Click">
                    <i:InvokeCommandAction Command="{Binding OpenFlyoutCommand}" CommandParameter="Subclass" />
                </i:EventTrigger>
            </i:Interaction.Triggers>
        </Button>

        <Button TabIndex="19" Name="btnSelectMfg"  Grid.Column="2" Grid.Row="2" Content="Select" Style="{StaticResource btn-primary}" Width="90"   Margin="10 2, 0, 3" 
                Command="{Binding OpenFlyoutCommand}" CommandParameter="Manufacturer" >
            <Button.ToolTip>
                <ToolTip Content="Select Mfg" Style="{StaticResource tooltip}"></ToolTip>
            </Button.ToolTip>
        </Button>

        <Button TabIndex="20" Name="btnSelectModel"  Grid.Column="2" Grid.Row="3" Content="Select" Style="{StaticResource btn-primary}" Width="90"   Margin="10 2, 0, 3" 
                >
            <Button.ToolTip>
                <ToolTip Content="Select Model" Style="{StaticResource tooltip}"></ToolTip>
            </Button.ToolTip>
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="Click">
                    <i:InvokeCommandAction Command="{Binding OpenFlyoutCommand}" CommandParameter="Model" />
                </i:EventTrigger>
            </i:Interaction.Triggers>
        </Button>

        <Button  TabIndex="22" Name="btnSelectAttributes" IsEnabled="{Binding AttributButtonEnable}"  Grid.Column="2" Grid.Row="5" Content="Select" Style="{StaticResource btn-primary}" Width="90"   Margin="10 2, 0, 3"  
                Command="{Binding OpenFlyoutCommand}"  CommandParameter="Attribute" >
            <Button.ToolTip>
                <ToolTip Content="Select Attributes" Style="{StaticResource tooltip}"></ToolTip>
            </Button.ToolTip>
        </Button>
    </Grid>
</UserControl>

Open the flyout code:

private void OpenFlyout(string selectType)
{
    Messenger.Default.Send<bool>(true, BroadcastMessageToken.ClassFlyout);
}

Code behind to set the focus:

private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
    IRequestFocus focus = (IRequestFocus)DataContext;
    focus.FocusRequested += OnFocusRequested;
}

private void OnFocusRequested(object sender, FocusRequestedEventArgs e)
{
    switch (e.PropertyName)
    {
        case "Class":
            Keyboard.Focus(btnSelectClass);
            btnSelectClass.Focusable = true;
            btnSelectClass.IsTabStop = true;
            btnSelectClass.Focus();

            //btnSelectClass.Cursor = Cursors.Hand;
            break;
    }
}

interface code set the focus:

public interface IRequestFocus
{
    event EventHandler<focusrequestedeventargs> FocusRequested;
}

public class FocusRequestedEventArgs : EventArgs
{
    public FocusRequestedEventArgs(string propertyName)
    {
        PropertyName = propertyName;
    }
    public string PropertyName { get; set; }
}

ViewModel code:

public class SelectViewModel : ViewModelBase, IRequestFocus
{
 public event EventHandler<focusrequestedeventargs> FocusRequested;//VC01 11/13/2023

 protected virtual void OnFocusRequested(string propertyName)
 {
     FocusRequested?.Invoke(this, new FocusRequestedEventArgs(propertyName));
 }
}

Code to notify the changes for property

private async Task SetSelectModel(string propertyName, object value)
{
    OnFocusRequested(nameof(Class));
}