wpf-controls – Page 4

How to handle the SelectionChanged event of ComboBox with MVVM in wpf?

May 14, 2023 by Tarik

MVVM solution: Bind the ItemsSource and SelectedItem properties of the ComboBox to properties in your ViewModel: <ComboBox ItemsSource=”{Binding MyItems}” SelectedItem=”{Binding MySelectedItem}”/> In MainViewModel.cs: public ObservableCollection<string> MyItems { get; set; } private string _mySelectedItem; public string MySelectedItem { get { return _mySelectedItem; } set { // Some logic here _mySelectedItem = value; } } Code-behind solution: … Read more

How to get children of a WPF container by type?

May 9, 2023 by Tarik

This extension method will search recursively for child elements of the desired type: public static T GetChildOfType<T>(this 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 … Read more

An integer value in WPF Resources?

May 1, 2023 by Tarik

To make that declaration you need to import the System namespace: xmlns:sys=”clr-namespace:System;assembly=mscorlib” … <sys:Int32 x:Key=”MyValue”>1234</sys:Int32> Note: you will need to use a Double for most WPF properties instead of an Int32

WPF: How to make canvas auto-resize?

April 19, 2023 by Tarik

No this is not possible (see snippet from MSDN below). However, if you want to have scrollbars and auto-resizing, consider using a Grid instead, and use the Margin property to position your items on this Grid.. Grid will tell the ScrollViewer how big he wants to be, and you will get the scrollbars.. Canvas will … Read more

wpf datagrid alternate row coloring

April 15, 2023 by Tarik

Finally, this is what I ended up with for generically setting alternate row colors. <Style TargetType=”{x:Type DataGrid}”> <Setter Property=”Background” Value=”#FFF” /> <Setter Property=”AlternationCount” Value=”2″ /> </Style> <Style TargetType=”{x:Type DataGridRow}”> <Style.Triggers> <Trigger Property=”ItemsControl.AlternationIndex” Value=”0″> <Setter Property=”Background” Value=”#CCC”></Setter> </Trigger> <Trigger Property=”ItemsControl.AlternationIndex” Value=”1″> <Setter Property=”Background” Value=”#EEE”></Setter> </Trigger> </Style.Triggers> </Style>

AutoComplete TextBox in WPF

April 13, 2023 by Tarik

You can find one in the WPF Toolkit, which is also available via NuGet. This article demos how to create a textbox which can auto-suggest items at runtime based on input, in this case, disk drive folders. WPF AutoComplete Folder TextBox Also take a look at this nice Reusable WPF Autocomplete TextBox, it was for … Read more

How to add context menu to wpf datagrid?

March 31, 2023 by Tarik

WPF ComboBox performance problems by binding a large collections

March 28, 2023 by Tarik

According to this blog: http://vbcity.com/blogs/xtab/archive/2009/12/15/wpf-using-a-virtualizingstackpanel-to-improve-combobox-performance.aspx I’ve tested it with this code: <ComboBox Name=”cbBlah” ItemsSource=”{Binding}”> <ComboBox.ItemsPanel> <ItemsPanelTemplate> <VirtualizingStackPanel /> </ItemsPanelTemplate> </ComboBox.ItemsPanel> </ComboBox> It works fine for first time and next times. It’s not necessary to code these lines: <VirtualizingStackPanel VirtualizingStackPanel.IsVirtualizing=”True” VirtualizingStackPanel.VirtualizationMode=”Recycling” />

C# how to get text value from PasswordBox?

March 9, 2023 by Tarik

You can get it from the Password property.

In WPF, how can I determine whether a control is visible to the user?

March 7, 2023 by Tarik

You can use this little helper function I just wrote that will check if an element is visible for the user, in a given container. The function returns true if the element is partly visible. If you want to check if it’s fully visible, replace the last line by rect.Contains(bounds). private bool IsUserVisible(FrameworkElement element, FrameworkElement … Read more