Is there a way to have a xaml page scroll to a particular object on a button click? For example, I have three buttons at the top of my page. I would like each button to move the scrollviewer to the top, middle, and bottom section of the page. How can I make this happen? Thanks!
I try to create the Xaml and to solve the problem. This is my solution.
This is the Xaml code.
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Grid.RowDefinitions>
<RowDefinition Height="100"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<Button HorizontalAlignment="Left" Content="Top" Click="Button_Click" ></Button>
<Button HorizontalAlignment="Center" Content="Center" Click="Button_Click_1" ></Button><Button Content="Botton" HorizontalAlignment="Right" Click="Button_Click_2" ></Button>
<ScrollViewer Grid.Row="1" Name="MyScrollViewer" MaxZoomFactor="9">
<StackPanel>
<TextBlock Name="TextBlock" Height="20"> </TextBlock>
<Rectangle Height="300" Width="100" Fill="BlanchedAlmond"></Rectangle>
<Rectangle Height="300" Width="100" Fill="Blue"></Rectangle>
<Rectangle Height="300" Width="100" Fill="BlueViolet"></Rectangle>
<Rectangle Height="300" Width="100" Fill="Chartreuse"></Rectangle>
<Rectangle Height="300" Width="100" Fill="Crimson"></Rectangle>
</StackPanel>
</ScrollViewer>
</Grid>
And this is the .cs Code
private void Button_Click(object sender, RoutedEventArgs e)
{
MyScrollViewer.ScrollToVerticalOffset(0);
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
var scrollableHeight = MyScrollViewer.ScrollableHeight;
var height= scrollableHeight / 2;
MyScrollViewer.ScrollToVerticalOffset(height);
}
private void Button_Click_2(object sender, RoutedEventArgs e)
{
MyScrollViewer.ScrollToVerticalOffset(MaxHeight);
}
}
Related
I’m using Material Design In XAML Toolkit C# ,MessageBox in material design WPF C# ,
I need like this or better Design for MessageBox 👌
I’ve tried use DialogHost but this Error happens
No loaded DialogHost instances.
private async void MenuPopupButton_OnClick(object sender, RoutedEventArgs e) {
var sampleMessageDialog = new SampleMessageDialog {
Message = {Text = "Goodbye"}
};
await DialogHost.Show(sampleMessageDialog, "RootDialog");
}
No loaded DialogHost instances.
I have developed one custom message box(using material design controls) in my application.
i'll show you the code below of WPF XAML and C#.
it contains three types of message boxes as below.
Yes,No
Ok
Ok,Cancel
Download code from below link.
https://github.com/sandeepjadhav75502/CustomMessageBoxWPF
WPF XAML Code
Heading
<Window x:Class="EVotingDashBoard.MessageBoxCustom"
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"
mc:Ignorable="d"
Title="MessageBoxWindow" Height="220" Width="500"
WindowStartupLocation="CenterScreen" WindowStyle="None" Background="White"
ResizeMode="CanResize" Topmost="True" ShowInTaskbar="False"
xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
TextElement.Foreground="{DynamicResource MaterialDesignBody}"
TextElement.FontWeight="Regular"
TextElement.FontSize="10"
TextOptions.TextFormattingMode="Ideal"
TextOptions.TextRenderingMode="Auto"
FontFamily="{DynamicResource MaterialDesignFont}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="197*"/>
<ColumnDefinition Width="295*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<materialDesign:Card x:Name="cardHeader" Grid.Row="0" Padding="10" Margin="0" materialDesign:ShadowAssist.ShadowDepth="Depth5" Background="{DynamicResource PrimaryHueDarkBrush}" Foreground="{DynamicResource PrimaryHueDarkForegroundBrush}" Visibility="Visible" Grid.ColumnSpan="2">
<StackPanel>
<TextBlock x:Name="txtTitle" HorizontalAlignment="Center" VerticalAlignment="Stretch" Style="{DynamicResource MaterialDesignTitleTextBlock}" FontSize="20" >Message Title</TextBlock>
</StackPanel>
</materialDesign:Card>
<StackPanel HorizontalAlignment="Right" Margin="0,5,5,0" VerticalAlignment="Top" Grid.Column="1">
<Button x:Name="btnClose" Click="btnClose_Click" Width="35" Height="35" Background="White" Foreground="{DynamicResource PrimaryHueDarkBrush}" Style="{StaticResource MaterialDesignFloatingActionDarkButton}">
<materialDesign:PackIcon Kind="Close" />
</Button>
</StackPanel>
<Grid Grid.Row="1" Grid.ColumnSpan="2">
<Grid Margin="20">
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition Height="auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid Grid.Row="0">
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<materialDesign:TransitioningContent>
<materialDesign:TransitioningContent.OpeningEffects >
<materialDesign:TransitionEffect Kind="FadeIn" />
<materialDesign:TransitionEffect Kind="SlideInFromBottom" />
</materialDesign:TransitioningContent.OpeningEffects>
<TextBox x:Name="txtMessage" HorizontalAlignment="Center" IsReadOnly="True" Grid.Row="0" Margin="5" materialDesign:HintAssist.Hint="" FontSize="18" Style="{StaticResource MaterialDesignFloatingHintTextBox}" />
</materialDesign:TransitioningContent>
</Grid>
<Grid Grid.Row="1" Margin="0,20,0,5">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="auto"/>
<ColumnDefinition Width="auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Button x:Name="btnOk" Click="btnOk_Click" Grid.Column="1" Style="{StaticResource MaterialDesignRaisedButton}" Margin="5" Width="100" Content="OK" ToolTip="Ok"/>
<Button x:Name="btnCancel" Click="btnCancel_Click" Grid.Column="2" Style="{StaticResource MaterialDesignRaisedButton}" Margin="5" Width="100" Content="Cancel" ToolTip="Cancel"/>
<Button x:Name="btnYes" Click="btnYes_Click" Grid.Column="1" Style="{StaticResource MaterialDesignRaisedButton}" Margin="5" Width="100" Content="Yes" ToolTip="Yes"/>
<Button x:Name="btnNo" Click="btnNo_Click" Grid.Column="2" Style="{StaticResource MaterialDesignRaisedButton}" Margin="5" Width="100" Content="No" ToolTip="No"/>
</Grid>
</Grid>
</Grid>
</Grid>
</Window>
C# Code Behind
/// <summary>
/// Interaction logic for MessageBoxCustom.xaml
/// </summary>
public partial class MessageBoxCustom : Window
{
public MessageBoxCustom(string Message, MessageType Type, MessageButtons Buttons)
{
InitializeComponent();
txtMessage.Text = Message;
switch (Type)
{
case MessageType.Info:
txtTitle.Text = "Info";
break;
case MessageType.Confirmation:
txtTitle.Text = "Confirmation";
break;
case MessageType.Success:
{
txtTitle.Text = "Success";
}
break;
case MessageType.Warning:
txtTitle.Text = "Warning";
break;
case MessageType.Error:
{
txtTitle.Text = "Error";
}
break;
}
switch (Buttons)
{
case MessageButtons.OkCancel:
btnYes.Visibility = Visibility.Collapsed; btnNo.Visibility = Visibility.Collapsed;
break;
case MessageButtons.YesNo:
btnOk.Visibility = Visibility.Collapsed; btnCancel.Visibility = Visibility.Collapsed;
break;
case MessageButtons.Ok:
btnOk.Visibility = Visibility.Visible;
btnCancel.Visibility = Visibility.Collapsed;
btnYes.Visibility = Visibility.Collapsed; btnNo.Visibility = Visibility.Collapsed;
break;
}
}
private void btnYes_Click(object sender, RoutedEventArgs e)
{
this.DialogResult = true;
this.Close();
}
private void btnCancel_Click(object sender, RoutedEventArgs e)
{
this.DialogResult = false;
this.Close();
}
private void btnOk_Click(object sender, RoutedEventArgs e)
{
this.DialogResult = true;
this.Close();
}
private void btnNo_Click(object sender, RoutedEventArgs e)
{
this.DialogResult = false;
this.Close();
}
private void btnClose_Click(object sender, RoutedEventArgs e)
{
this.DialogResult = false;
this.Close();
}
}
public enum MessageType
{
Info,
Confirmation,
Success,
Warning,
Error,
}
public enum MessageButtons
{
OkCancel,
YesNo,
Ok,
}
we can call it like
private void Button_Close(object sender, RoutedEventArgs e)
{
bool? Result = new MessageBoxCustom("Are you sure, You want to close
application ?", MessageType.Confirmation, MessageButtons.YesNo).ShowDialog();
if (Result.Value)
{
Application.Current.Shutdown();
}
}
Consider using this package that has the following extra benefit features:
Custom styles for border window, message foreground and background, title foreground and background, border, etc
Button to copy message box details to clipboard
Scrollable message box content
Message content is .NET UIElement which can host any content
So I built this sample application and using a custom WindowChrome with WPF and C#. Everytime I try to maximize my window using the buttons I made, the maximized window becomes slightly off? Like by a few pixels. What is happening?
<Window x:Class="TestApp.MainWindow"
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:local="clr-namespace:TestApp"
mc:Ignorable="d"
Title="TestApp"
WindowStyle="None"
WindowStartupLocation="CenterScreen"
MinHeight="500" MinWidth="940">
<WindowChrome.WindowChrome>
<WindowChrome
ResizeBorderThickness="6"
CaptionHeight="20"
GlassFrameThickness="0"
CornerRadius="0"
/>
</WindowChrome.WindowChrome>
<!-- Application -->
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="26" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<!-- WindowChrone Header -->
<Grid Background="{StaticResource WindowChromeBrush}" Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="30"/>
<ColumnDefinition Width="30"/>
<ColumnDefinition Width="30"/>
</Grid.ColumnDefinitions>
<Button Grid.Column="0" Content="RelayC" />
<Button Click="MinimizeWindow" Grid.Column="2" Style="{StaticResource WindowChromeButton}">
<Image Source="{StaticResource window_minimize_icon}"/>
</Button>
<Button Click="MaximizeWindow" Grid.Column="3" Style="{StaticResource WindowChromeButton}">
<Image Source="{StaticResource window_maximize_icon}" />
</Button>
<Button Click="CloseWindow" Grid.Column="4" Style="{StaticResource WindowChromeButton}">
<Image Source="{StaticResource window_close_icon}" />
</Button>
</Grid>
<!--- Main Content -->
<Grid Grid.Row="1">
</Grid>
</Grid>
</Window>
Here is my sample code for the Button Functions:
private void MinimizeWindow(object sender, RoutedEventArgs e) => this.WindowState = WindowState.Minimized;
private void MaximizeWindow(object sender, RoutedEventArgs e) => this.WindowState = WindowState.Maximized;
private void CloseWindow(object sender, RoutedEventArgs e) => this.Close();
What am I doing wrong?
I ended up finding a sort of elegant solution to this problem. I simply assigned a name to the outermost grid, detected whenever it was maximized and added a margin to make sure the application was fully encompassing the screen and not going over. Then, when the screen size changed, I would remove said margin.
Here is some of my code:
Main functions:
private bool isMaximized = false;
private void CheckMaximizeChange(object sender, SizeChangedEventArgs e)
{
if (WindowState == WindowState.Maximized || (isMaximized && WindowState != WindowState.Minimized)) ChangeWindow();
}
private void MaximizeWindow(object sender, RoutedEventArgs e) => this.WindowState ^= WindowState.Maximized;
private void ChangeWindow()
{
isMaximized = !isMaximized;
MaximizeImageButton.Source = FindResource(MaximizeImageButton.Source == FindResource("window_maximize_icon") ? "window_restore_icon" : "window_maximize_icon") as DrawingImage;
MainGrid.Margin = new Thickness(MainGrid.Margin == new Thickness(0) ? 7 : 0);
}
then in the constructor of the application:
SizeChanged += CheckMaximizeChange;
I have a rectangle textbox in WPF and there is already a button inside the textbox which is clickable. I need to make the entire rectangle textbox clickable, so users can click anywhere in the textbox rather than just the button to interact.
Is it possible to do so?
Here is my XAML:
<Grid Background="{StaticResource TinyGrayBrush}" Height="260" Width="530" Margin="10,10,10,10" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="120*"/>
<ColumnDefinition Width="140*"/>
</Grid.ColumnDefinitions>
<Grid Grid.Column="0">
<Image x:Name="imgCard" Source="{StaticResource Exception-NoImageAvailable}" Stretch="Fill" />
<Image x:Name="hotpickEn" Source="{StaticResource HotPickEn}" Height="20" Width="70" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="0,30,0,0" Visibility="Hidden" />
<Image x:Name="hotpickCh" Source="{StaticResource HotPickCH}" Height="20" Width="70" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="0,30,0,0" Visibility="Hidden" />
</Grid>
<Grid x:Name="gdEnglish" Visibility="Visible" Grid.Column="1">
<Grid.RowDefinitions>
<RowDefinition Height="12*"/>
<RowDefinition Height="62*"/>
<RowDefinition Height="90*"/>
<RowDefinition Height="5*"/>
<RowDefinition Height="55*"/>
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Grid.Resources>
<Style TargetType="TextBlock">
<Setter Property="Margin" Value="25,5,25,5"/>
</Style>
</Grid.Resources>
<TextBlock Grid.Row="1" x:Name="txtTitle" Text="SPARKLING SUNDAY BRUNCH BUFFET" FontSize="20" TextWrapping="Wrap" FontWeight="Medium" Foreground="{StaticResource SemiDarkGrayBrush}" Margin="5,0,5,6.5" />
<TextBlock Grid.Row="2" x:Name="txtDesc" Text="Pop your Sunday Morning with luxury sparkling bubble" FontSize="16" TextWrapping="Wrap" Foreground="{StaticResource GrayBrush}" Margin="5,3.5,5,6.5" />
<TextBlock Grid.Row="3" x:Name="txtPoint" Text="138,900 GP" FontSize="21" TextWrapping="Wrap" FontWeight="Medium" Foreground="{StaticResource GrayBrush}" Margin="25,3.5,25,6" />
<Button Grid.Row="4" x:Name="btnFindOutMore" Content="FIND OUT MORE OR REDEEM" Style="{StaticResource SmallWhiteRedButton}" Margin="12,0,12,0" FontSize="20" />
</Grid>
<Grid x:Name="gdChinese" Visibility="Hidden" Grid.Column="1">
<Grid.RowDefinitions>
<RowDefinition Height="12*"/>
<RowDefinition Height="62*"/>
<RowDefinition Height="90*"/>
<RowDefinition Height="5*"/>
<RowDefinition Height="55*"/>
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Grid.Resources>
<Style TargetType="TextBlock">
<Setter Property="Margin" Value="25,5,25,5"/>
</Style>
</Grid.Resources>
<TextBlock Grid.Row="1" x:Name="txtCHTitle" Text="SPARKLING SUNDAY BRUNCH BUFFET" FontSize="20" TextWrapping="Wrap" FontWeight="Medium" Foreground="{StaticResource SemiDarkGrayBrush}" HorizontalAlignment="Left" Margin="5,4.667,0,5.333" />
<TextBlock Grid.Row="2" x:Name="txtCHDesc" Text="Pop your Sunday Morning with luxury sparkling bubble" FontSize="16" TextWrapping="Wrap" Foreground="{StaticResource GrayBrush}" HorizontalAlignment="Left" Margin="5,4.667,0,5.667" />
<TextBlock Grid.Row="3" x:Name="txtCHPoint" Text="138,900 GP" FontSize="21" TextWrapping="Wrap" FontWeight="Medium" Foreground="{StaticResource GrayBrush}" HorizontalAlignment="Left" Margin="25,3.5,25,6" Width="105" />
<Button x:Name="btnCHFindOutMore" Grid.Row="4" Content="FIND OUT MORE OR REDEEM" Style="{StaticResource SmallWhiteRedButton}" Margin="15,0,10,0"/>
</Grid>
As you are using Code-Behind for this:
You basically subscribe to the events of the Grid too
gdEnglish.TouchDown += gdEnglish_TouchDown;
gdEnglish.TouchUp += gdEnglish_TouchUp;
gdEnglish.TouchLeave += gdEnglish_TouchLeave;
gdEnglish.MouseDown += gdEnglish_MouseDown;
gdEnglish.MouseUp += gdEnglish_MouseUp;
gdEnglish.MouseLeave += gdEnglish_MouseLeave;
add a new private variable to indicate the current state
private bool gdEnglish_clickflag = false;
and create the different event handlers
private void gdEnglish_MouseLeave(object sender, MouseEventArgs e)
{
gdEnglish_clickflag = false;
}
private void gdEnglish_MouseUp(object sender, MouseButtonEventArgs e)
{
if (gdEnglish_clickflag)
{
gdEnglish_clickflag = false;
e.Handled = true;
//////////
// YOUR //
// CODE //
//////////
}
}
private void gdEnglish_MouseDown(object sender, MouseButtonEventArgs e)
{
gdEnglish_clickflag = true;
}
private void gdEnglish_TouchLeave(object sender, TouchEventArgs e)
{
gdEnglish_clickflag = false;
}
private void gdEnglish_TouchUp(object sender, TouchEventArgs e)
{
if (gdEnglish_clickflag)
{
gdEnglish_clickflag = false;
e.Handled = true;
//////////
// YOUR //
// CODE //
//////////
}
}
private void gdEnglish_TouchDown(object sender, TouchEventArgs e)
{
gdEnglish_clickflag = true;
}
I still want to recommend that you research the topic MVVM with WPF
it will make things like this more clean and easy
I try to make a "email messenger". I have two windows. Main window, there is ribbon with bookmarks and one button (New message). This button invoke second window NewMessage. The Mainwindow is owner of the NewMessage window.
MainWindow:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
NewMessage newmessage = new NewMessage();
newmessage.Show();
}
}
}
MainWindow XAML:
<Window x:Class="Messenger.MainWindow"
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:local="clr-namespace:Messenger"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Button Content="New Message" Height="20" Width="80
" HorizontalAlignment="Left" Margin="35,46,0,0" VerticalAlignment="Top" Click="Button_Click" />
<TabControl HorizontalAlignment="Left" Height="254" Margin="34,44,0,0" VerticalAlignment="Top" Width="461" Background="{x:Null}" SelectedIndex="1">
<TabItem Header="Delivered" Visibility="Hidden" Width="80">
<Grid Background="#FFE5E5E5"/>
</TabItem>
<TabItem Header="Delivered" Visibility="Visible" Width="80">
<Grid Background="#FFE5E5E5"/>
</TabItem>
<TabItem Header="Sent" Width="80">
<Grid Background="#FFE5E5E5"/>
</TabItem>
<TabItem Header="Trash" Width="80">
<Grid Background="#FFE5E5E5"/>
</TabItem>
</TabControl>
</Grid>
NewMessage:
public partial class NewMessage : Window
{
public NewMessage()
{
InitializeComponent();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
this.Close();
}
}
}
NewMessage XAML:
<Window x:Class="Messenger.NewMessage"
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:local="clr-namespace:Messenger"
mc:Ignorable="d"
Title="NewMessage" Height="351.047" Width="814.398">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="4*"/>
<ColumnDefinition Width="27*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="23*"/>
<RowDefinition Height="24*"/>
<RowDefinition Height="243*"/>
<RowDefinition Height="31*"/>
</Grid.RowDefinitions>
<Label Grid.Row="0" Content="Komu" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<TextBox Grid.Row="0" Grid.Column="1" HorizontalAlignment="Stretch" VerticalAlignment="Top" />
<Label Grid.Row="1" Content="Předmět" HorizontalAlignment="Left" VerticalAlignment="Top"/>
<TextBox Grid.Row="1" Grid.Column="1" HorizontalAlignment="Stretch" VerticalAlignment="Top" />
<RichTextBox HorizontalAlignment="Left" Height="243" Grid.Row="2" VerticalAlignment="Top" Width="806" Grid.ColumnSpan="2">
<FlowDocument>
<Paragraph>
<Run Text="Sem zadejte text zprávy"/>
</Paragraph>
</FlowDocument>
</RichTextBox>
<Button Grid.Row="3" Content="Odeslat" Grid.Column="1" HorizontalAlignment="Right" VerticalAlignment="Top" Width="75" Margin="0,5,90,0"/>
<Button Grid.Row="3" Content="Storno" Grid.Column="1" HorizontalAlignment="Right" VerticalAlignment="Top" Width="75" Margin="0,5,10,0" Click="Button_Click"/>
</Grid>
I would like to, when I minimize NewMessage window, this window minimize to the bottom of MainWindow "taskbar". If you know gmail, there is the same principle. Any idea?
I've created a simple custom messagebox that automatically scales depending on the length of the text to be displayed :
public partial class CustomMessageBox : Window
{
public CustomMessageBox(string title, string text)
{
InitializeComponent();
ResizeMode = ResizeMode.NoResize;
label.Content = text;
Title = title;
}
public static void Show(string title, string text)
{
CustomMessageBox box = new CustomMessageBox(title, text);
box.SizeToContent = SizeToContent.WidthAndHeight;
box.ShowDialog();
}
private void button_Click(object sender, RoutedEventArgs e)
{
Close();
}
}
This works nicely however my button is clamping to the bottom side of the window because the window automatically scales :
And the button seems to be moving once the message gets longer :
How would I make sure the button stays centered and have a margin of around 10px from the bottom so it doesn't look that clamped?
I tried to set the Margin manually but that doesn't seem to work.
XAML (largely generated by the designer) :
<Window x:Class="RapidEvent.CustomMessageBox"
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:local="clr-namespace:RapidEvent"
mc:Ignorable="d"
Background="{DynamicResource WindowBackgroundBrush}"
Title="" Height="Auto" Width="Auto">
<Grid>
<StackPanel>
<Label x:Name="label" Content="" HorizontalAlignment="Left" Margin="10,0,0,0" VerticalAlignment="Top" FontSize="13px" RenderTransformOrigin="0.392,0.486"/>
<Button x:Name="button" x:FieldModifier="public" IsDefault="True" Content="_Ok" HorizontalAlignment="Left" Margin="110,40,0,0" VerticalAlignment="Top" Width="80" Height="21" Click="button_Click"/>
</StackPanel>
</Grid>
</Window>
Simply change your StackPanel to a Grid and the HorizonalAlignment of your button to Center and take off all but the bottom margin. You'll also need to set the VerticalAlignment to Bottom. You also need to put the button on row 1.
This way the button will be clamped to the bottom of the dialog and always centred.
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Label x:Name="label" Content=""
HorizontalAlignment="Left" Margin="10,0,0,0"
VerticalAlignment="Top" FontSize="13px"
RenderTransformOrigin="0.392,0.486"/>
<Button Grid.Row="1" x:Name="button" x:FieldModifier="public"
IsDefault="True" Content="_Ok"
HorizontalAlignment="Center" Margin="0,0,0,20"
VerticalAlignment="Bottom" Width="80" Height="21"/>
</Grid>
Use grid instead of StackPanel:
<Grid >
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<telerik:Label x:Name="label" Content="LSFFD" HorizontalAlignment="Left" Margin="10,0,0,0" VerticalAlignment="Top" FontSize="13px" RenderTransformOrigin="0.392,0.486"/>
<Button Grid.Row="1" x:Name="button" x:FieldModifier="public" Content="_Ok" HorizontalAlignment="Center" Margin="0 0 0 10" VerticalAlignment="Bottom" Width="80" Height="21" Click="button_Click"/>
</Grid>