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Programmatically generated expanders with scrollable content resizing to window

I'm looking for a better way to make a programmatically generated window with the following behavior.
That is: List of expanders that can be initialized programmatically, each of which contains scrollable content larger than can be displayed in the window (in this case a datagrid). When an expander is expanded it's contents are limited to the available size of the window, while allowing all the rest of the expanders to be seen and manipulated. Additionally only one expander can be open at any given time.
This functionality seems that it could be useful in a lot of application menus, so I was surprised how difficult it was to implement. Is there a better way than what I did?
XAML (surprisingly simple):
<Window x:Class="ExpanderScrollExample.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"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="200">
<Grid>
<ItemsControl ItemsSource="{Binding Dict}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Grid Loaded="GridLoaded" ScrollViewer.CanContentScroll="False"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Expander Header ="{Binding Key, Mode=OneWay}" Expanded="Expander_Expanded" Collapsed="Expander_Collapsed">
<DataGrid ItemsSource="{Binding Path=Value}"/>
</Expander>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
Code Behind (with most of the magic):
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
namespace ExpanderScrollExample
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = new MainWindowViewModel();
}
private void GridLoaded(object sender, RoutedEventArgs e)
{
Grid grid = sender as Grid;
grid.LayoutUpdated += (s, e2) =>
{
var childCount = grid.Children.Count;
int rowsToAdd = (childCount - grid.RowDefinitions.Count);
for (int row = 0; row < rowsToAdd; row++)
{
RowDefinition rowDefinition = new RowDefinition();
rowDefinition.Height = new GridLength(0, GridUnitType.Auto);
grid.RowDefinitions.Add(rowDefinition);
}
for (int i = 0; i < childCount; i++)
{
var child = grid.Children[i] as FrameworkElement;
Grid.SetRow(child, i);
}
};
}
private void Expander_Expanded(object sender, RoutedEventArgs e)
{
ContentPresenter parentDataContext = VisualTreeHelper.GetParent(sender as DependencyObject) as ContentPresenter;
Grid grid = VisualTreeHelper.GetParent(parentDataContext as DependencyObject) as Grid;
grid.RowDefinitions[Grid.GetRow(parentDataContext)].Height = new GridLength(1, GridUnitType.Star);
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(grid); i++)
{
DependencyObject neighborDataContext = VisualTreeHelper.GetChild(grid, i);
for (int j = 0; j < VisualTreeHelper.GetChildrenCount(neighborDataContext); j++)
{
DependencyObject neighborExpander = VisualTreeHelper.GetChild(neighborDataContext, j);
if (neighborExpander is Expander && neighborExpander != sender)
{
((Expander)neighborExpander).IsExpanded = false;
this.Collapse(neighborExpander as Expander);
}
}
}
}
private void Expander_Collapsed(object sender, RoutedEventArgs e)
{
this.Collapse(sender as Expander);
}
private void Collapse(Expander expander)
{
ContentPresenter parent = VisualTreeHelper.GetParent(expander as DependencyObject) as ContentPresenter;
Grid grandparent = VisualTreeHelper.GetParent(parent as DependencyObject) as Grid;
grandparent.RowDefinitions[Grid.GetRow(parent)].Height = new GridLength(0, GridUnitType.Auto);
}
}
}
ViewModel (only for data generation)
using System.Collections.Generic;
namespace ExpanderScrollExample
{
class MainWindowViewModel
{
public Dictionary<string, List<MyClass>> Dict { get; }
public MainWindowViewModel()
{
Dict = new Dictionary<string, List<MyClass>>();
for ( int i = 0; i < 5; i++ )
{
string key = "Header " + i.ToString();
Dict[key] = new List<MyClass>();
for ( int j = 0; j < 100; j++)
{
Dict[key].Add(new MyClass(j, i*100 + j));
}
}
}
public class MyClass
{
public int Column1 {get; set;}
public int Column2 { get; set; }
public MyClass( int column1, int column2)
{
Column1 = column1;
Column2 = column2;
}
}
}
}
I also typically try to confirm with MVVM pattern, but was unable to do so in this case.
Generating items controls in grid is taken from here.
I also considered using style triggers to expand/collapse and set size as described in this answer but I couldn't think of a good way how to bind the dynamically generated rows with expanders.
Is there a better way to do this?

1. Only one Expander expanded at a given time
To make sure that only one Expander is expanded at a given time, you can create an Attached Behavior. I implemented one for reference.
ExpanderGroupBehavior (inspired by RadioButton)
<Expander wpf:ExpanderGroupBehavior.GroupName="ExpanderGroup01" />
This makes sure that only one Expander within the same group is expanded.
2. Expanded Expander fill available space
To achieve that, you may create your own Panel which handles that for you.
See How to get controls in WPF to fill available space? and https://learn.microsoft.com/en-us/dotnet/framework/wpf/controls/how-to-create-a-custom-panel-element

C# UWP Listview/GridView mark of selected item

I am creating UWP app, and I maked external arrow "marker" of selected item in listview...
Like this:
I have managed to achieve this with next code:
var current = lvMain.Items.FirstOrDefault(a => (a as MyModel).Selected) as MyModel;
ListViewItem selected = lvMain.ContainerFromItem(current) as ListViewItem;
GeneralTransform generalTransform1 = gvEpg.TransformToVisual(selected);
Point currentPoint = generalTransform1.TransformPoint(new Point());
In Scroll change event I am calling this and set the arrow position by the Point of my item. And this is working.
But, I want to simplified this. Is there any kind of binding or something like that, that would make arrow always follow the item?

Here's the sample.
XAML MainPage:
<Page.Resources>
<DataTemplate x:Key="DataTemplate">
<Canvas Height="80" Width="200">
<TextBlock Text="{Binding}"/>
</Canvas>
</DataTemplate>
</Page.Resources>
<StackPanel Orientation="Horizontal">
<ListView x:Name="ListView" Width="400"
SelectionChanged="ListView_OnSelectionChanged"
ItemTemplate="{StaticResource DataTemplate}"/>
<Canvas x:Name="ParentCanvas">
<Image x:Name="Arrow"
Stretch="UniformToFill" Width="200" Height="80"
Source="Assets/Red_Left_Arrow.png"/>
</Canvas>
</StackPanel>
Code behind:
private readonly List<string> _names = new List<string>();
private Visual _rectangleVisual;
private Visual _parentVisual;
public MainPage()
{
InitializeComponent();
Loaded += MainPage_Loaded;
}
private void MainPage_Loaded(object sender, RoutedEventArgs e)
{
for (int i = 0; i < 32; i++)
{
_names.Add("item " + i);
}
ListView.ItemsSource = _names;
_parentVisual = ElementCompositionPreview.GetElementVisual(ParentCanvas);
_rectangleVisual = ElementCompositionPreview.GetElementVisual(Arrow);
var border = VisualTreeHelper.GetChild(ListView, 0) as Border;
var scrollViewer = border.Child as ScrollViewer;
var scrollerProperties = ElementCompositionPreview.GetScrollViewerManipulationPropertySet(scrollViewer);
var offsetExpressionAnimation = _rectangleVisual.Compositor.CreateExpressionAnimation("Scroller.Translation.Y");
offsetExpressionAnimation.SetReferenceParameter("Scroller", scrollerProperties);
_rectangleVisual.StartAnimation("Offset.Y", offsetExpressionAnimation);
}
private void ListView_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
var listViewItem = ListView.ContainerFromItem(ListView.SelectedItem) as ListViewItem;
var listItemVisual = ElementCompositionPreview.GetElementVisual(listViewItem);
_parentVisual.Offset = new Vector3(_parentVisual.Offset.X, listItemVisual.Offset.Y, 0);
}
Looks like what you asked for:

c# wpf - ListView.ScrollIntoView(LastItem) does not work properly

like some other people here i have a ListView (updated via binding in a GridView).
I want to keep the last inserted Item in the View. So i tried
LView.ScrollIntoView(LView.Items[LView.Items.Count - 1]);
This is working almost fine. Altough the first item which would have to be scrolled into view is only shown like 80% of its whole row (depending on how high i define the whole ListView, i almost got 100%).
The real problem is that the following items which should get scrolled into view are not shown. It is also noticable at the Scrollbar itself which is not at the bottom.
Last Item is not shown
Here is the code of my MainWindow.
public partial class MainWindow : Window
{
private InterfaceCtrl ICtrl;
private ListView LView;
public MainWindow()
{
InitializeComponent();
this.ICtrl = new InterfaceCtrl();
this.ICtrl.ProgressCollection.CollectionChanged += this.CollectionChanged;
Grid MainGrid = new Grid();
this.Content = MainGrid;
GridView gv = new GridView();
Binding StartTimeStampBinding = new Binding() { Path = new PropertyPath("StartTS"), Mode = BindingMode.OneWay, StringFormat = "dd.MM.yyyy - HH:mm:ss.fff" };
GridViewColumn gvTCStartTS = new GridViewColumn() { Header = "Time", Width = 150.00, DisplayMemberBinding = StartTimeStampBinding };
gv.Columns.Add(gvTCStartTS);
LView = new ListView() { Height = 192, Width = 250, HorizontalAlignment = HorizontalAlignment.Left, VerticalAlignment = VerticalAlignment.Top, View = gv, ItemsSource = this.ICtrl.ProgressCollection };
MainGrid.Children.Add(LView);
ICtrl.StartMyThread();
}
private void CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
Application.Current.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, new System.Action(delegate ()
{
if (LView != null && LView.Items.Count > 0)
{
LView.UpdateLayout();
//LView.ScrollIntoView(LView.Items[LView.Items.Count - 1]);
LView.SelectedIndex = LView.Items.Count;
LView.ScrollIntoView(LView.SelectedItem);
}
}));
}
}
Thank you.
EDIT:
It seemed to be a timing problem, although all the wanted data was in the LView at the right time i tried a workaround with a Textbox bound to the Timestamp.
TextBox tb = new TextBox(); // { Width = 250, Height = 28, Margin= new Thickness(10,100,1,0)};
tb.SetBinding( TextBox.TextProperty , new Binding("LastMsgTimestamp") { Source = this.ICtrl, Mode = BindingMode.OneWay, StringFormat = "dd.MM.yyyy - HH:mm:ss.fff" });
tb.TextChanged += this.UpdateScrollbar;
tb.Visibility = Visibility.Hidden;
It seems to me like there is a timing issue within the binding to the LView and the fired Event of the ObservableCollection. This also includes the PropertyChanged of the ObservableCollection.
I tried the events TargetUpdated and SoruceUpdated directly within LView but those didn't came up at all.

You could try to call any of the ScrollToBottom() or ScrollToVerticalOffset() methods of the ListView's internal ScrollViewer element:
private void CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
Application.Current.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, new System.Action(delegate ()
{
if (LView != null && LView.Items.Count > 0)
{
LView.UpdateLayout();
ScrollViewer sv = GetChildOfType<ScrollViewer>(LView);
if (sv != null)
sv.ScrollToBottom();
LView.SelectedIndex = LView.Items.Count;
LView.ScrollIntoView(LView.SelectedItem);
}
}));
}
private static T GetChildOfType<T>(DependencyObject depObj) where T : DependencyObject
{
if (depObj == null)
return null;
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
{
var child = VisualTreeHelper.GetChild(depObj, i);
var result = (child as T) ?? GetChildOfType<T>(child);
if (result != null)
return result;
}
return null;
}

I have made the following sample. You could try to call ScrollToBottom in inner ScrollViewer as #mm8 points out. Nevertheless when saw the answer I was already making my sample, so here it is:
Codebehind
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
namespace ListViewScroll
{
public partial class MainWindow : Window
{
public ObservableCollection<string> Names { get; set; }
public MainWindow()
{
InitializeComponent();
Names = new ObservableCollection<string>();
ListView.ItemsSource = Names;
}
private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
{
Names.Add("Some Name" + ++someInt);
// Get the border of the listview (first child of a listview)
var border = VisualTreeHelper.GetChild(ListView, 0) as Decorator;
// Get scrollviewer
var scrollViewer = border.Child as ScrollViewer;
scrollViewer.ScrollToBottom();
}
private static int someInt;
}
}
XAML
<Window x:Class="ListViewScroll.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<ListView Grid.Row="0" Name="ListView"/>
<Button Content="Add" FontSize="20" Grid.Row="1"
Click="ButtonBase_OnClick"/>
</Grid>
</Window>
In this case I am handling the scrolling in the button click event but you may change this to fit your requirements
It works, I have tested.
Hope this helps

WPF Drag and Drop with Adorner using mouse and touch

I want this to be good question, so I'll write in details what I would like to achieve, what I've found on the internet and I show what I've done so far and what I've tried.
I need to add drag and drop functionality to my application. I have Images (basically controls) that I want to drag to items of listbox.
Here is sample UI:
And here is usage I have now:
As You can see I'm able to drag one of four images and drop it over listbox item.
If I move image over correct target (listbox image) image near cursor disappears and everything works fine, but when I don't drop image on list item (I release mouse) that image stays on screen.
I've based my solution on answers to this question, and I'm unable to remove that unwanted window (image near cursor)
My XAML looks like this:
<Window x:Class="DragDrop.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Drag'n'Drop" Height="350" Width="525"
DataContext="{Binding RelativeSource={RelativeSource Self}}">
<Grid>
<ListBox HorizontalAlignment="Right" HorizontalContentAlignment="Stretch" Height="300" Margin="0,10,10,0" VerticalAlignment="Top" Width="234" ItemsSource="{Binding People}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical" AllowDrop="True" PreviewDrop="UIElement_OnPreviewDrop">
<TextBlock Text="{Binding Name}" FontWeight="Bold" />
<ProgressBar Height="20" Value="{Binding Points}" Margin="0,0,0,0"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<Image HorizontalAlignment="Left" Height="72" Margin="10,10,0,0" VerticalAlignment="Top" Width="72" Source="Images/coins-60000-icon.png" RenderTransformOrigin="0.5,0.5"
PreviewMouseLeftButtonDown="OnMouseTouchDown"
PreviewTouchDown="OnMouseTouchDown"
PreviewGiveFeedback="UIElement_OnPreviewGiveFeedback" Tag="10"/>
<Image HorizontalAlignment="Left" Height="72" Margin="87,10,0,0" VerticalAlignment="Top" Width="72" Source="Images/coins-700000-icon.png" RenderTransformOrigin="0.5,0.5"
PreviewMouseLeftButtonDown="OnMouseTouchDown"
PreviewTouchDown="OnMouseTouchDown"
PreviewGiveFeedback="UIElement_OnPreviewGiveFeedback" Tag="20"/>
<Image HorizontalAlignment="Left" Height="72" Margin="10,87,0,0" VerticalAlignment="Top" Width="72" Source="Images/coins-7000-icon.png" RenderTransformOrigin="0.5,0.5"
PreviewMouseLeftButtonDown="OnMouseTouchDown"
PreviewTouchDown="OnMouseTouchDown"
PreviewGiveFeedback="UIElement_OnPreviewGiveFeedback" Tag="30"/>
<Image HorizontalAlignment="Left" Height="72" Margin="87,87,0,0" VerticalAlignment="Top" Width="72" Source="Images/coins-700-icon.png" RenderTransformOrigin="0.5,0.5"
PreviewMouseLeftButtonDown="OnMouseTouchDown"
PreviewTouchDown="OnMouseTouchDown"
PreviewGiveFeedback="UIElement_OnPreviewGiveFeedback" Tag="40"/>
</Grid>
</Window>
And code behind:
public partial class MainWindow
{
private readonly ObservableCollection<Person> _people = new ObservableCollection<Person>();
public ObservableCollection<Person> People
{
get { return _people; }
}
public MainWindow()
{
InitializeComponent();
_people.Add(new Person() {Name = "Person1", Points = 10});
_people.Add(new Person() {Name = "Person2", Points = 0});
_people.Add(new Person() {Name = "Person3", Points = 40});
}
private void OnMouseTouchDown(object sender, InputEventArgs e)
{
var item = sender as Image;
if (item == null) return;
var draggedItem = item;
var points = Convert.ToInt32(draggedItem.Tag);
CreateDragDropWindow(draggedItem);
System.Windows.DragDrop.DoDragDrop(draggedItem, points, DragDropEffects.Move);
}
private Window _dragdropWindow;
private void CreateDragDropWindow(Visual dragElement)
{
_dragdropWindow = new Window
{
WindowStyle = WindowStyle.None,
AllowsTransparency = true,
AllowDrop = false,
Background = null,
IsHitTestVisible = false,
SizeToContent = SizeToContent.WidthAndHeight,
Topmost = true,
ShowInTaskbar = false
};
Rectangle r = new Rectangle
{
Width = ((FrameworkElement) dragElement).ActualWidth/2,
Height = ((FrameworkElement) dragElement).ActualHeight/2,
Fill = new VisualBrush(dragElement)
};
_dragdropWindow.Content = r;
Win32Point w32Mouse = new Win32Point();
GetCursorPos(ref w32Mouse);
_dragdropWindow.Left = w32Mouse.X;
_dragdropWindow.Top = w32Mouse.Y;
_dragdropWindow.Show();
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool GetCursorPos(ref Win32Point pt);
[StructLayout(LayoutKind.Sequential)]
internal struct Win32Point
{
public Int32 X;
public Int32 Y;
};
private void UIElement_OnPreviewGiveFeedback(object sender, GiveFeedbackEventArgs e)
{
Win32Point w32Mouse = new Win32Point();
GetCursorPos(ref w32Mouse);
_dragdropWindow.Left = w32Mouse.X;
_dragdropWindow.Top = w32Mouse.Y;
}
private void UIElement_OnPreviewDrop(object sender, DragEventArgs e)
{
//var droppedData = e.Data.GetData(typeof(Image)) as Image;
var droppedData = (Int32) e.Data.GetData(typeof (Int32));
var stackPanel = sender as StackPanel;
if (stackPanel != null)
{
var student = stackPanel.DataContext as Person;
//int targetIndex = _people.IndexOf(student);
if (student != null) student.Points += droppedData;
}
if (_dragdropWindow != null)
{
_dragdropWindow.Close();
_dragdropWindow = null;
}
}
}
public class Person : INotifyPropertyChanged
{
private string _name;
private int _points;
public string Name
{
get { return _name; }
set
{
if (value == _name) return;
_name = value;
OnPropertyChanged();
}
}
public int Points
{
get { return _points; }
set
{
if (value == _points) return;
_points = value;
if (_points >= 100)
{
_points -= 100;
Debug.WriteLine("100!");
}
OnPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}
I found over the internet that I can use class that extends Adorner and I found some examples:
http://nonocast.cn/adorner-in-wpf-part-5-drag-and-drop/ - (WaybackMachine archive link)
http://www.zagstudio.com/blog/488#.VfiMSBHtmko
http://www.infragistics.com/community/blogs/alex_fidanov/archive/2009/07/28/drag-amp-drop-with-datapresenter-family-controls.aspx
https://github.com/punker76/gong-wpf-dragdrop
but all of them show how to drag items from collections (ItemsControls). Third link was promising, but I wasn't able to adopt it to my needs.
So my questions are:
How can I hide that small image window in my example when I cancel drag (MouseUp or incorrect drag target)
Show I use Adorner and how can I use it in my code? I need to show it when I start drag and hide when I drop Image correctly or I cancel drag or drop target is incorrect
I'm starting with WPF so please try to understand my frustration - I've spend last two evenings and night trying to get this working.

1) Modify your OnMouseTouchDown handler to include assigning ContinueDragHandler to dragged item before starting the drag, like this
private void OnMouseTouchDown(object sender, InputEventArgs e)
{
var item = sender as FrameworkElement;
if (item == null) return;
var draggedItem = item;
var points = Convert.ToInt32(draggedItem.Tag);
CreateDragDropWindow(draggedItem);
System.Windows.DragDrop.AddQueryContinueDragHandler(draggedItem, DragContrinueHandler);
System.Windows.DragDrop.DoDragDrop(draggedItem, points, DragDropEffects.Move);
}
And the handler itself:
public void DragContrinueHandler(object sender, QueryContinueDragEventArgs e)
{
if (e.Action == DragAction.Continue && e.KeyStates != DragDropKeyStates.LeftMouseButton)
{
_dragdropWindow.Close();
}
}
2) I believe that creating a new window to display image next to a cursor is a dirty dirty hack. There are plenty of various articles around about using adorners with drag'n'drop. Althought your approach works and doesn't require a lot of code. Adorners do, on the other hand. I think you should create another question, if you fail following certain tutorial, with code examples and what steps you took

How can i get all the buttons in the uniformgrid and scroll it to see them all?

i am building an application to show all the software installed in the computer, i already have all the buttons to show with the respective icon, but when i show them, the uniformgrid only shows the buttons that fit in to the window, i thought a scrollbar will show them, but i get to the end of the window and the buttons still missing! how can i show them all with a scrollbar?
Here is the XAML code:
<Window x:Class="apple.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow">
<Grid>
<DockPanel Name="dock">
<ScrollViewer VerticalScrollBarVisibility="Auto">
<UniformGrid Name="gridx" DockPanel.Dock="Top" Rows="7" Columns="7">
</UniformGrid>
</ScrollViewer>
</DockPanel>
</Grid>
</Window>
Here is the c# code:
namespace apple
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public string[] link = Directory.GetFiles(#"C:\ProgramData\Microsoft\Windows\Start Menu\Programs", "*.lnk", SearchOption.AllDirectories);
public MainWindow()
{
this.ResizeMode = ResizeMode.NoResize;
//this.WindowStyle = WindowStyle.None;
this.WindowState = WindowState.Maximized;
InitializeComponent();
masterGUI();
}
public void masterGUI()
{
gridx.Height = System.Windows.SystemParameters.PrimaryScreenHeight;
IconImage[] ico = null;
Bitmap[] img = null;
string[] list = null;
list = new string[link.Length];
ico = new Icon[link.Length];
img = new Bitmap[link.Length];
for (int n = 0; n < link.Length; n++)
{
ImageBrush ib = new ImageBrush();
System.Windows.Controls.Button newBtn = new Button();
list[n] = System.IO.Path.GetFileNameWithoutExtension(link[n]);
FileToImageIconConverter some = new FileToImageIconConverter(link[n]);
ImageSource imgSource = some.Icon;
ib.ImageSource = imgSource;
newBtn.Name = "a" + n;
newBtn.Background = ib;
newBtn.Content = list[n];
newBtn.Click += new RoutedEventHandler(newBtn_Click);
gridx.Children.Add(newBtn);
}
}
private void newBtn_Click(object sender, RoutedEventArgs e)
{
Button clicked = (Button)sender;
string test = null;
test = clicked.Name.Replace("a","0");
this.Close();
System.Diagnostics.Process.Start(link[Int32.Parse(test)]);
}
}
}

Remove the Grid and DockPanel and set either UniformGrid.Rows or UniformGrid.Columns, not both. All you need is Window, ScrollViewer, and UniformGrid:
<Window>
<ScrollViewer>
<UniformGrid Name="gridx" Columns="7"/>
</ScrollViewer>
</Window>
And to do it in a more idiomatic WPF fashion, you should have something like this:
<Window>
<ScrollViewer>
<ItemsControl ItemsSource="{Binding Programs}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<UniformGrid Columns="7"/>
You would then expose a Programs collection from your data source and would thus automatically generate an item for each installed program.