I have a ListView with pretty long listelement at times. I would like to create an event, where if I drag the mouse over an element, the whole name appears in a tooltip-like small window with the whole text of the item. This way the user can read it even if it is too long for the ListView window width.
I am a bit stuck, because I find no MouseOver event for the ListView elements. I would probably have to go on with a custom Style for my ListView, but I don't have experience with Styles.
I would really appreciate a little help, to get me started!
Create an AttachedProperty for MouseMove and hook your list view with the property. The attached property can be used to any element in your application.
Attached Property
public class MouseBehaviour
{
public static readonly DependencyProperty MouseMoveCommandProperty =
DependencyProperty.RegisterAttached("MouseMoveCommand", typeof(ICommand), typeof(MouseBehaviour), new FrameworkPropertyMetadata(new PropertyChangedCallback(MouseMoveCommandChanged)));
private static void MouseMoveCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
FrameworkElement element = (FrameworkElement)d;
element.MouseMove += new MouseEventHandler(element_MouseMove);
}
static void element_MouseMove(object sender, MouseEventArgs e)
{
FrameworkElement element = (FrameworkElement)sender;
ICommand command = GetMouseMoveCommand(element);
command.Execute(e);
}
public static void SetMouseMoveCommand(UIElement element, ICommand value)
{
element.SetValue(MouseMoveCommandProperty, value);
}
public static ICommand GetMouseMoveCommand(UIElement element)
{
return (ICommand)element.GetValue(MouseMoveCommandProperty);
}
}
XAML
xmlns:mousebehav="clr-namespace:your namespace"
<ListView mousebehav:MouseBehaviour.MouseMoveCommand="{Binding MouseMoveCommand}">
VM
private RelayCommand _MouseMoveCommand;
public RelayCommand MouseMoveCommand
{
get
{
if (_MouseMoveCommand== null) return _MouseMoveCommand= new RelayCommand(param => Execute_MouseMoveCommand((MouseEventArgs)param));
return _MouseMoveCommand;
}
set { _MouseMoveCommand= value; }
}
private void Execute_MouseMoveCommand(MouseEventArgs param)
{
//your logic to expand or ??
}
Thanks for the answer. After a few hours of experimenting, I managed to solve it quite compact from the xaml:
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="ToolTip" Value="{Binding Name}" />
</Style>
</ListView.ItemContainerStyle>
Related
My application has about 15 different UserControls that are uniformly loaded into a content-area at runtime.
My project is 100% MVVM-compliant, so I have the following XAML inserted into every UserControl's XAML:
<UserControl
...
xmlns:intr="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
>
<intr:Interaction.Triggers>
<intr:EventTrigger EventName="Loaded">
<intr:InvokeCommandAction Command="{Binding ViewLoadedCommand}"/>
</intr:EventTrigger>
</intr:Interaction.Triggers>
<!-- Rest of UserControl content here -->
</UserControl>
Obviously this isn't ideal and is also a violation of DRY.
What is the best way to have this XAML applied to this set of UserControls? (but not every UserControl, so a simple <Style Type="UserControl" /> would be inappropriate).
I use behavior implemented as attached property. It has two major advantages over System.Windows.Interactivity:
it can be defined in style.
much less xaml code in the views
in your case, the view could look like:
<UserControl ...
my:AttachedCommands.LoadedCommand="{Binding ViewLoadedCommand}">
In my solution, I'm not using commands, but I call methods on viewmodel if the viewmodel implements IViewModelLifeCycle interface:
public interface IViewModelLifeCycle
{
void Activate(object extraData);
void Deactivate();
}
All my views uses this style:
<Style x:Key="ViewBaseStyle">
<Setter Property="my:ViewModelLifeCycleBehavior.ActivateOnLoad" Value="True" />
and the behavior:
public static class ViewModelLifeCycleBehavior
{
public static readonly DependencyProperty ActivateOnLoadProperty = DependencyProperty.RegisterAttached("ActivateOnLoad", typeof (bool), typeof (ViewModelLifeCycleBehavior),
new PropertyMetadata(ActivateOnLoadPropertyChanged));
public static void SetActivateOnLoad(FrameworkElement element, bool value)
{
element.SetValue(ActivateOnLoadProperty, value);
}
public static bool GetActivateOnLoad(FrameworkElement element)
{
return (bool)element.GetValue(ActivateOnLoadProperty);
}
private static void ActivateOnLoadPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
{
if (DesignerProperties.GetIsInDesignMode(obj)) return;
var element = (FrameworkElement)obj;
element.Loaded -= ElementLoaded;
element.Unloaded -= ElementUnloaded;
if ((bool) args.NewValue == true)
{
element.Loaded += ElementLoaded;
element.Unloaded += ElementUnloaded;
}
}
static void ElementLoaded(object sender, RoutedEventArgs e)
{
var element = (FrameworkElement) sender;
var viewModel = (IViewModelLifeCycle) element.DataContext;
if (viewModel == null)
{
DependencyPropertyChangedEventHandler dataContextChanged = null;
dataContextChanged = (o, _e) =>
{
ElementLoaded(sender, e);
element.DataContextChanged -= dataContextChanged;
};
element.DataContextChanged += dataContextChanged;
}
else if (element.ActualHeight > 0 && element.ActualWidth > 0) //to avoid activating twice since loaded event is called twice on TabItems' subtrees
{
viewModel.Activate(null);
}
}
private static void ElementUnloaded(object sender, RoutedEventArgs e)
{
var element = (FrameworkElement)sender;
var viewModel = (IViewModelLifeCycle)element.DataContext;
viewModel.Deactivate();
}
}
TIP:
Create your custom Item Template in Visual Studio for View and ViewModel. its very easy and saves a lot of time. The item template can contain xaml code with the trigger/behaviour, pointing to your base style, your d:DataContext definition and your viewmodel class.
you could create a "base-load" Usercontrol with the Interaction.Triggers and just put a ContentPresenter in it where you bind the real content to.
<UserControl x:class="OneOfMyOtherControls">
<MyBaseUserControl>
<!-- your UserControl Content-->
</MyBaseUserControl>
</UserControl>
Is there any feature of the TextBlock that allows scrolling to the end always?
I've seen a number of examples that do this in the code behind,
I want to keep the principle of MVVM and not touch the code behind,
I'm looking for a way to do this in XAML.
Have one?
I am assuming your TextBlock is nested within a ScrollViewer. In this case you are going to have to create an attached property. See this related question:
How to scroll to the bottom of a ScrollViewer automatically with Xaml and binding?
i.e. create an attached property:
public static class Helper
{
public static bool GetAutoScroll(DependencyObject obj)
{
return (bool)obj.GetValue(AutoScrollProperty);
}
public static void SetAutoScroll(DependencyObject obj, bool value)
{
obj.SetValue(AutoScrollProperty, value);
}
public static readonly DependencyProperty AutoScrollProperty =
DependencyProperty.RegisterAttached("AutoScroll", typeof(bool), typeof(Helper), new PropertyMetadata(false, AutoScrollPropertyChanged));
private static void AutoScrollPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var scrollViewer = d as ScrollViewer;
if (scrollViewer != null && (bool)e.NewValue)
{
scrollViewer.ScrollToBottom();
}
}
}
Then bind as follows:
<ScrollViewer local:Helper.AutoScroll="{Binding BooleanViewModelPropertyThatTriggersScroll}" .../>
I want to copy the content of one text box to another text box by clicking the mouse.
How do I bind a mouse click event?
This sample is for RightClick, but you can adjust the event according to your needs:
<TextBox>
<TextBox.InputBindings>
<MouseBinding Gesture="RightClick" Command="{Binding YourCommand}" />
</TextBox.InputBindings>
</TextBox>
Edit: I uploaded on my SkyDrive a sample app that illustrates how to use this method in order to achieve exactly what you need. Please be advised that it will only work for .NET Framework 4+
Want to add a behavior to a control ? Just use the Ramora pattern !
Hope this helps
Use this code for TreeView
<TreeView commandBehaviors:MouseDoubleClick.Command="{Binding YourCommand}"
commandBehaviors:MouseDoubleClick.CommandParameter="{Binding}"
.../>
Use this code for TreeViewItem
<TreeView ItemsSource="{Binding Projects}">
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="commandBehaviors:MouseDoubleClick.Command"
Value="{Binding YourCommand}"/>
<Setter Property="commandBehaviors:MouseDoubleClick.CommandParameter"
Value="{Binding}"/>
</Style>
</TreeView.ItemContainerStyle>
</TreeView>
Use this code to create a new behavior MouseDoubleClick
public class MouseDoubleClick
{
public static DependencyProperty CommandProperty =
DependencyProperty.RegisterAttached("Command",
typeof(ICommand),
typeof(MouseDoubleClick),
new UIPropertyMetadata(CommandChanged));
public static DependencyProperty CommandParameterProperty =
DependencyProperty.RegisterAttached("CommandParameter",
typeof(object),
typeof(MouseDoubleClick),
new UIPropertyMetadata(null));
public static void SetCommand(DependencyObject target, ICommand value)
{
target.SetValue(CommandProperty, value);
}
public static void SetCommandParameter(DependencyObject target, object value)
{
target.SetValue(CommandParameterProperty, value);
}
public static object GetCommandParameter(DependencyObject target)
{
return target.GetValue(CommandParameterProperty);
}
private static void CommandChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
Control control = target as Control;
if (control != null)
{
if ((e.NewValue != null) && (e.OldValue == null))
{
control.MouseDoubleClick += OnMouseDoubleClick;
}
else if ((e.NewValue == null) && (e.OldValue != null))
{
control.MouseDoubleClick -= OnMouseDoubleClick;
}
}
}
private static void OnMouseDoubleClick(object sender, RoutedEventArgs e)
{
Control control = sender as Control;
ICommand command = (ICommand)control.GetValue(CommandProperty);
object commandParameter = control.GetValue(CommandParameterProperty);
command.Execute(commandParameter);
}
}
It sounds like you are inventing a new behaviour for your textbox :)
I would just consider if the users of your program understands and likes this behaviour.
Maybe it is easier to understand the funcionality if it is just a button you have to click - it is also faster to implement :)
I think you could bind mouse gestures to commands. Take a look at this: http://www.thejoyofcode.com/Invoking_a_Command_on_a_Double_Click_or_other_Mouse_Gesture.aspx
I'm not sure what exactly you're wanting to bind to.
There is no readily available MouseClick event as far as i'm aware.
the Click event as you'd find on a Button is inherited from ButtonBase and is not readily available on most controls.
MouseDoubleClick is inherited from Control and available on anythning deriving from it.
in your example it sounds like a simple Button with its Click event handled might do the trick.
To bind to the click event, you just need to specify the event handler for the event in the Button.
Something like:
XAML:
<TextBox Name=TextBoxOne />
<TextBox Name=TextBoxTwo />
<Button Click="CopyTextButton_Click"/>
And in your code behind:
void CopyTextButton_Click(object sender, RoutedEventArgs e)
{
//Copy the text and anything else you need done
}
Otherwise if this is a more specialised scenario, you might want to investigate using a UserControl or as AndrewS answered above, a Command.
Hope it helps.
You can easily do this by creating a new behavior.
<TextBox
MouseDoubleClick="SelectAddress"
GotKeyboardFocus="SelectAddress"
PreviewMouseLeftButtonDown="SelectivelyIgnoreMouseButton" />
Here's the code behind:
private void SelectAddress(object sender, RoutedEventArgs e)
{
TextBox tb = (sender as TextBox);
if (tb != null)
{
tb.SelectAll();
}
}
private void SelectivelyIgnoreMouseButton(object sender,
MouseButtonEventArgs e)
{
TextBox tb = (sender as TextBox);
if (tb != null)
{
if (!tb.IsKeyboardFocusWithin)
{
e.Handled = true;
tb.Focus();
}
}
}
Please update this snippet according to your need.
I want to create a Style for a WPF ListBox that includes a Button in the ControlTemplate that the user can click on and it clears the ListBox selection.
I dont want to use codebehind so that this Style can be applied to any ListBox.
I have tried using EventTriggers and Storyboards and it has proved problematic as it only works first time and stopping the Storyboard sets the previous selection back.
I know I could use a user control but I want to know if it is possible to achieve this using only a Style.
It is not possible to achieve this using XAML and only the classes provided by the .NET framework. However you can still produce a reusable solution by defining a new command (call it ClearSelectionCommand) and a new attached property (call it ClearSelectionOnCommand).
Then you can incorporate those elements into your style.
Example:
public class SelectorBehavior
{
public static RoutedCommand
ClearSelectionCommand =
new RoutedCommand(
"ClearSelectionCommand",
typeof(SelectorBehavior));
public static bool GetClearSelectionOnCommand(DependencyObject obj)
{
return (bool)obj.GetValue(ClearSelectionOnCommandProperty);
}
public static void SetClearSelectionOnCommand(
DependencyObject obj,
bool value)
{
obj.SetValue(ClearSelectionOnCommandProperty, value);
}
public static readonly DependencyProperty ClearSelectionOnCommandProperty =
DependencyProperty.RegisterAttached(
"ClearSelectionOnCommand",
typeof(bool),
typeof(SelectorBehavior),
new UIPropertyMetadata(false, OnClearSelectionOnCommandChanged));
public static void OnClearSelectionOnCommandChanged(
DependencyObject d,
DependencyPropertyChangedEventArgs e)
{
Selector selector = d as Selector;
if (selector == null) return;
bool nv = (bool)e.NewValue, ov = (bool)e.OldValue;
if (nv == ov) return;
if (nv)
{
selector.CommandBindings.Add(
new CommandBinding(
ClearSelectionCommand,
ClearSelectionCommand_Executed,
ClearSelectionCommand_CanExecute));
}
else
{
var cmd = selector
.CommandBindings
.Cast<CommandBinding>()
.SingleOrDefault(x =>
x.Command == ClearSelectionCommand);
if (cmd != null)
selector.CommandBindings.Remove(cmd);
}
}
public static void ClearSelectionCommand_Executed(
object sender,
ExecutedRoutedEventArgs e)
{
Selector selector = (Selector)sender;
selector.SelectedIndex = -1;
}
public static void ClearSelectionCommand_CanExecute(
object sender,
CanExecuteRoutedEventArgs e)
{
e.CanExecute = true;
}
}
Example usage - XAML:
<Window x:Class="ClearSelectionBehaviorLibrary.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:ClearSelectionBehaviorLibrary"
Title="Window1" Height="300" Width="300">
<Window.Resources>
<Style x:Key="MyStyle" TargetType="Selector">
<Setter
Property="local:SelectorBehavior.ClearSelectionOnCommand"
Value="True"/>
</Style>
</Window.Resources>
<Grid>
<DockPanel>
<Button
DockPanel.Dock="Bottom"
Content="Clear"
Command="{x:Static local:SelectorBehavior.ClearSelectionCommand}"
CommandTarget="{Binding ElementName=TheListBox}"/>
<ListBox
Name="TheListBox"
ItemsSource="{Binding MyData}"
Style="{StaticResource MyStyle}"/>
</DockPanel>
</Grid>
</Window>
Example usage - Code Behind:
public partial class Window1 : Window
{
public List<string> MyData { get; set; }
public Window1()
{
MyData = new List<string>
{
"aa","bb","cc","dd","ee"
};
InitializeComponent();
DataContext = this;
}
}
I have the same command that I want to use for two controls on a dialog type window. As potentially interesting background, I'm using Josh Smith's ViewModel / RelayCommand ideas, since I am new to WPF and it's the first thing I've seen that I can actually understand from a big picture point of view.
So the command is a property of a ViewModel, and with the Button's built-in support, it is trivial and painless to bind to the command in the XAML:
<Button ... Command="{Binding Path=PickCommand}" Content="_Ok"></Button>
Now in a ListView, the only way I have gotten to use the same command hooked up to trigger on a double click is by using an event handler:
<ListView ...
ItemsSource="{Binding Path=AvailableProjects}"
SelectedItem="{Binding Path=SelectedProject, Mode=TwoWay}"
MouseDoubleClick="OnProjectListingMouseDoubleClick"
>
private void OnProjectListingMouseDoubleClick(object sender, MouseButtonEventArgs e) {
var vm = (ProjectSelectionViewModel) DataContext;
vm.Pick(); // execute the pick command
}
Is there a way to do this by binding the way the button does it?
Cheers,
Berryl
<------- implementation - is there a better way? --->
Your SelctionBehavior class was spot on, but I was confused at your xaml code. By setting the "Style" on the listViewItem I was getting the children of the DataContext where the command I want to execute lives. So I attached the behavior to the ListView itself:
<ListView ...Style="{StaticResource _attachedPickCommand}" >
And put the style in a resource dictionary:
<Style x:Key="_attachedPickCommand" TargetType="ListView">
<Setter Property="behaviors:SelectionBehavior.DoubleClickCommand" Value="{Binding Path=PickCommand}" />
</Style>
It works! But it 'feels' awkward setting the style property of the list view. Is this just because I am not comfortable with style as more than something visual in wpf or is there a better way to do this?
Cheers, and thanks!
Berryl
Yes there is! You can use attached behaviors and bind the command to that behavior.
public class SelectionBehavior {
public static readonly DependencyProperty CommandParameterProperty=
DependencyProperty.RegisterAttached("CommandParameter", typeof(object), typeof(SelectionBehavior));
public static readonly DependencyProperty DoubleClickCommandProperty=
DependencyProperty.RegisterAttached("DoubleClickCommand", typeof(ICommand), typeof(SelectionBehavior),
new PropertyMetadata(OnDoubleClickAttached));
private static void OnDoubleClickAttached(DependencyObject d, DependencyPropertyChangedEventArgs e) {
var fe=(FrameworkElement)d;
if(e.NewValue!=null && e.OldValue==null) {
fe.PreviewMouseDown+=fe_MouseDown;
} else if(e.NewValue==null && e.OldValue!=null) {
fe.PreviewMouseDown-=fe_MouseDown;
}
}
private static void fe_MouseDown(object sender, MouseButtonEventArgs e) {
if(e.ClickCount==2) {
var dep=(FrameworkElement)sender;
var command=GetDoubleClickCommand(dep);
if(command!=null) {
var param=GetCommandParameter(dep);
command.Execute(param);
}
}
}
public static ICommand GetDoubleClickCommand(FrameworkElement element) {
return (ICommand)element.GetValue(DoubleClickCommandProperty);
}
public static void SetDoubleClickCommand(FrameworkElement element, ICommand value) {
element.SetValue(DoubleClickCommandProperty, value);
}
public static object GetCommandParameter(DependencyObject element) {
return element.GetValue(CommandParameterProperty);
}
public static void SetCommandParameter(DependencyObject element, object value) {
element.SetValue(CommandParameterProperty, value);
}
}
and in the xaml you would need to set a style for a ListViewItem which represents your data in the ListView. Example
<ListView>
<ListView.ItemContainerStyle>
<Style TargetType="{x:Type ListViewItem}">
<Setter Property="local:SelectionBehavior.DoubleClickCommand" Value="{Binding Path=DataContext.PickCommand}"/>
<Setter Property="local:SelectionBehavior.CommandParameter" Value="{Binding Path=DataContext}"/>
</Style>
</ListView.ItemContainerStyle>
</ListView>
Here is some more information about the Attached Behavior pattern