Custom WPF MessageBox does not return MessageBoxResult - wpf

Question

This is the xaml "SidiMessageBoxWindow.xaml" file:
<Window
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" mc:Ignorable="d">
<Border>
<Grid x:Name="mainGrid" Margin="0">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<ScrollViewer Grid.Row="0" VerticalScrollBarVisibility="Auto" Margin="0">
<TextBlock x:Name="TextBlock" TextWrapping="Wrap" Text="TextBlock" ScrollViewer.VerticalScrollBarVisibility="Auto" Height="Auto"/>
</ScrollViewer>
<Grid Grid.Row="1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Height="Auto" Width="Auto" Margin="0,10,0,0">
<Button x:Name="btnCancel" Content="Cancel" Width="Auto" MinWidth="0" Height="30"
HorizontalAlignment="Right" HorizontalContentAlignment="Center" VerticalAlignment="Center" VerticalContentAlignment="Center"
Margin="0,0,45,0" Padding="4,0,4,0" BorderThickness="1" />
<Button x:Name="btnOk" Content="Ok" Width="Auto" MinWidth="40" Height=" 30"
HorizontalAlignment="Right" HorizontalContentAlignment="Center" VerticalAlignment="Center" VerticalContentAlignment="Center"
Margin="0" Padding="4,0,4,0" BorderThickness="1" />
</Grid>
</Grid>
</Border>
and here the "SidiMessageBox1" class
I can't use "messageBox.ShowDialog();" here because I have to use the class "NTWindow" which I don't have access to.
public class SidiMessageBox1 : SidiMessageBoxWindow1
{
public static MessageBoxResult Show(ChartControl chartControl, string text, MessageBoxButton buttons = MessageBoxButton.OK)
{
if (chartControl == null)
{
return MessageBoxResult.None;
}
var messageBox = CreateMessageBox(chartControl, text, buttons);
messageBox.Show();
return messageBox.MsgBoxResult;
}
private static SidiMessageBoxWindow1 CreateMessageBox(ChartControl chartControl, string text, MessageBoxButton buttons)
{
return new SidiMessageBoxWindow1(text, buttons)
{
Owner = chartControl.OwnerChart,
Foreground = Application.Current.TryFindResource("FontControlBrush") as SolidColorBrush
};
}
}
and here is the SidiMessageBoxWindow1 class
public class SidiMessageBoxWindow1 : NTWindow
{
private static readonly string xamlFilePath = Path.Combine(Globals.UserDataDir, #"bin\Custom\AddOns\Sidi\SidiMessageBoxWindow.xaml");
private string text;
private Button btnOk, btnCancel;
private TextBlock textBlock;
private MessageBoxButton buttons;
public SidiMessageBoxWindow1()
{
}
public SidiMessageBoxWindow1(string text, MessageBoxButton buttons)
{
this.text = text;
Caption = "SidiMessageBox";
Topmost = true;
MinHeight = 100;
MinWidth = 200;
ResizeMode = ResizeMode.NoResize;
SizeToContent = SizeToContent.WidthAndHeight;
WindowStartupLocation = WindowStartupLocation.CenterOwner;
Content = LoadXaml(xamlFilePath);
Buttons = buttons;
}
private void OkButton_Click(object sender, RoutedEventArgs e)
{
btnOk.Click -= OkButton_Click;
Close();
}
private void CancelButton_Click(object sender, RoutedEventArgs e)
{
btnCancel.Click -= CancelButton_Click;
Close();
}
private DependencyObject LoadXaml(string xmlFilePath)
{
Window page;
FileStream fs = new FileStream(xmlFilePath, FileMode.Open);
page = (Window)XamlReader.Load(fs);
btnOk = LogicalTreeHelper.FindLogicalNode(page, "btnOk") as Button;
btnCancel = LogicalTreeHelper.FindLogicalNode(page, "btnCancel") as Button;
textBlock = LogicalTreeHelper.FindLogicalNode(page, "TextBlock") as TextBlock;
textBlock.Text = text;
return page.Content as DependencyObject;
}
public MessageBoxButton Buttons
{
get
{
return buttons;
}
set
{
buttons = value;
btnCancel.Visibility = Visibility.Collapsed;
btnOk.Visibility = Visibility.Collapsed;
switch (buttons)
{
case MessageBoxButton.OK:
btnOk.Visibility = Visibility.Visible;
btnOk.Click += OkButton_Click;
break;
case MessageBoxButton.OKCancel:
btnCancel.Visibility = Visibility.Visible;
btnOk.Visibility = Visibility.Visible;
btnOk.Click += OkButton_Click;
btnCancel.Click += CancelButton_Click;
break;
}
}
}
public MessageBoxResult MsgBoxResult { get; set; }
}
call:
var result = SidiMessageBox1.Show(ChartControl, "text");
the messageboxwindow looks like this:
everything works fine, as it should, except that I don't get a "MessageBoxResult" back. Unfortunately I don't know how to do that with this code.
I thank "BionicCode" for his explanation and hope for your understanding, because i am still quite a beginner ;-)

Answer 1

To use the Thread class is considered an obsolete programming model. Since the introduction of async and await with .NET Framework 4.5 the recommended programming model is the Microsoft Docs: Task asynchronous programming model.
As the member name Dispatcher.InvokeAsync suggests, this method is awaitable and supports asynchronous execution.
Your code actually does not execute the Window on a new thread. Because you use post related code to the Dispatcher, the Window is shown on the main thread.
Showing another Window will not block the other Window instances.
Additionally, your posted code is quite smelly. You should never block a constructor. But showing a modal dialog from a constructor will block construction. A constructor must initialize the members and return immediately.
Instead you must create and show the Window instance from your static Show method:
public static MessageBoxResult Show(ChartControl chartControl, string text, MessageBoxButton buttons)
{
if (chartControl == null)
{
return MessageBoxResult.None;
}
SidiMessageBoxWindow messageBox = CreateMessageBox(chartControl, text, buttons);
// If just an OK button, allow the user to just move away from the dialog
if (buttons == MessageBoxButton.OK)
{
messageBox.Show();
}
else
{
messageBox.ShowDialog();
}
return messageBox.MsgBoxResult;
}
private static SidiMessageBoxWindow CreateMessageBox(ChartControl chartControl, string text, MessageBoxButton buttons)
{
return new SidiMessageBoxWindow(xamlFilePath, logFilePath, text, buttons, chartControl)
{
Owner = chartControl.OwnerChart,
Foreground = Application.Current.TryFindResource("FontControlBrush") as SolidColorBrush
};
}
private SidiMessageBoxWindow(ChartControl chartControl, string text, MessageBoxButton buttons)
{
this.chartControl = chartControl;
this.text = text;
this.buttons = buttons;
}