Hi
I'm trying to get rid of the annoying "About Silverlight" context menu that pops up whenever you right click in a Silverlight application. I've added the usual ways:
In App.xaml
rootVisual.MouseRightButtonDown += ((s, args) => args.Handled = true);
and the same for all ChildWindows.
The problem that persist is in all "pop up"-controls like comboboxes and datepicker calender popup. There I can't get rid of it. I would like to handle the right click in a style that I can make implicit for the entire application. Is this possible? Can I solve it some other smart way?
Best
Daniel
The answer was to inherit the combobox and make a custom control like this:
public class CellaComboBox : ComboBox
{
public CellaComboBox()
{
DropDownOpened += _dropDownOpened;
DropDownClosed += _dropDownClosed;
}
private static void _dropDownClosed(object sender, EventArgs e)
{
HandlePopupRightClick(sender, false);
}
private static void _dropDownOpened(object sender, EventArgs e)
{
HandlePopupRightClick(sender, true);
}
private static void HandlePopupRightClick(object sender, bool hook)
{
ComboBox box = (ComboBox)sender;
var popup = box.GetChildElement<Popup>();
if (popup != null)
{
HookPopupEvent(hook, popup);
}
}
static void HookPopupEvent(bool hook, Popup popup)
{
if (hook)
{
popup.MouseRightButtonDown += popup_MouseRightButtonDown;
popup.Child.MouseRightButtonDown += popup_MouseRightButtonDown;
}
else
{
popup.MouseRightButtonDown -= popup_MouseRightButtonDown;
popup.Child.MouseRightButtonDown -= popup_MouseRightButtonDown;
}
}
static void popup_MouseRightButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
e.Handled = true;
}
with the extension method for framworkelement looking like this:
public static class FrameworkElementExtensions
{
public static TType GetChildElement<TType>(this DependencyObject parent) where TType : DependencyObject
{
TType result = default(TType);
if (parent != null)
{
result = parent as TType;
if (result == null)
{
for (int childIndex = 0; childIndex < VisualTreeHelper.GetChildrenCount(parent); ++childIndex)
{
var child = VisualTreeHelper.GetChild(parent, childIndex) as FrameworkElement;
result = GetChildElement<TType>(child) as TType;
if (result != null) return result;
}
}
}
return result;
}
}
You need to handle the DatePicker in the same way but instead of DropDownOpened and DropDownClosed you use CalenderOpened and CalenderClosed
C# Corner has an article for fixing the about popup on Silverlight 3:
Disable Context Menu in Silverlight 3 Application
Related
I have an attached property called "SelectAllOnFocus". Values of true/false.
public static class TextBoxProps
{
private static void MyTextBoxKeyUp(object sender, KeyEventArgs e)
{
if (e.Key == Key.Escape)
{
((TextBox)sender).Text = string.Empty;
}
}
public static void SetSelectAllOnFocus(DependencyObject dependencyObject, bool selectAllOnFocus)
{
if (!ReferenceEquals(null, dependencyObject))
{
dependencyObject.SetValue(SelectAllOnFocus, selectAllOnFocus);
}
}
public static bool GetSelectAllOnFocus(DependencyObject dependencyObject)
{
if (!ReferenceEquals(null, dependencyObject))
{
return (bool)dependencyObject.GetValue(SelectAllOnFocus);
}
else
{
return false;
}
}
private static void OnSelectAllOnFocus(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
bool selectAllOnFocus = (bool)e.NewValue == true;
var theTextBox = d as TextBox;
if (selectAllOnFocus && theTextBox != null)
{
theTextBox.PreviewMouseDown -= MyTextBoxMouseEnter; theTextBox.PreviewMouseDown += MyTextBoxMouseEnter;
}
}
private static void MyTextBoxMouseEnter(object sender, MouseEventArgs e)
{
((TextBox)sender).SelectAll();
e.Handled = false;
}
public static readonly DependencyProperty SelectAllOnFocus
= DependencyProperty.RegisterAttached("SelectAllOnFocus", typeof(bool), typeof(TextBoxEscapeProperty),
new FrameworkPropertyMetadata(false, new PropertyChangedCallback(OnSelectAllOnFocus)));
}
What happens is the following:
The PreviewMouseDown event gets triggered.
The MyTextBoxMouseEnter method gets called.
The SelectAll() Method gets called.
When I do a "watch" on ((TextBox)sender).SelectedText, the value is correct (meaning whatever is in the textbox is showing up as selectedText).
The textbox itself is unchanged. No text is selected.
This is part of a general WPF style. All textboxes in the application should receive this property and it's associated behavior.
I'm stumped. Any ideas?
Thanks
What happens if you call ((TextBox)sender).UpdateLayout(); immediately after the SelectAll command? Or maybe you need to set the Keyboard focus to the text box.
It might be a better option to use something like this, which works if the text box is being selected with the mouse or the keyboard. (You'll need to modify it to check your "SelectAllOnFocus" property)
In your App.xaml.cs
protected override void OnStartup(StartupEventArgs e)
{
// Select the text in a TextBox when it receives focus.
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.PreviewMouseLeftButtonDownEvent, new MouseButtonEventHandler(SelectivelyIgnoreMouseButton));
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.GotKeyboardFocusEvent, new RoutedEventHandler(SelectAllText));
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.MouseDoubleClickEvent, new RoutedEventHandler(SelectAllText));
base.OnStartup(e);
}
void SelectivelyIgnoreMouseButton(object sender, MouseButtonEventArgs e)
{
// Find the TextBox
DependencyObject parent = e.OriginalSource as UIElement;
while (parent != null && !(parent is TextBox))
parent = VisualTreeHelper.GetParent(parent);
if (parent != null)
{
var textBox = (TextBox)parent;
if (!textBox.IsKeyboardFocusWithin)
{
// If the text box is not yet focused, give it the focus and
// stop further processing of this click event.
textBox.Focus();
e.Handled = true;
}
}
}
void SelectAllText(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
textBox.SelectAll();
}
As you can see below, I want to start moving when the component visibility changes.
because otherwise I need the user to click again to start the movement, and that is bad in terms of usability for my application.
public MoveILayoutControl()
{
InitializeComponent();
this.IsVisibleChanged += new DependencyPropertyChangedEventHandler(MoveILayoutControl_IsVisibleChanged);
this.moveThumb.DragDelta += new DragDeltaEventHandler(MoveThumb_DragDelta);
}
void MoveILayoutControl_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (this.IsVisible)
{
// Raise Drag Event !?
}
}
private void MoveThumb_DragDelta(object sender, DragDeltaEventArgs e)
{
var myData = DataContext as ILayoutVisual;
if (myData != null)
{
Point dragDelta = new Point(e.HorizontalChange, e.VerticalChange);
if (myData.Rotation != 0)
{
Matrix toCalculate = ((this.Parent as FrameworkElement).RenderTransform).Value;
if (toCalculate != null)
{
dragDelta = toCalculate.Transform(dragDelta);
}
}
myData.X += dragDelta.X;
myData.Y += dragDelta.Y;
}
}
I believe the only way is using reflection to change the internal values of the thumb. Changing the property "IsDragging" (not tested).
I looked up the source code of Thumb and I think a better way is to simulate a MouseLeftButtonEvent on the thumb:
var evt = new MouseButtonEventArgs(mouseDevice, timestamp, MouseButton.Left)
{
RoutedEvent = UIElement.MouseLeftButtonDownEvent
};
thumb.RaiseEvent(evt);
I have a simple problem. I am trying to add a dependency property to a combo box. I want to be able to display a value on the face of the combo box when it is initially displayed. There is a ContentPresenter with a TextBlock inside the ComboBox. That TextBlock gets set when a user selects an item in the ComboBox. How can I set that with a default value (not one of the items)? Show something like 'choose one'.
I can extend the ComboBox with a 'DefaultDisplay' dependency property but how do I 'link' that property to the TextBlock that is part of the control template?
Thanks for any help on this.
Pat
Instead of a dependency property I'd suggest using a behavior to do this. I actually already had one of these written for this problem. Give it a try by adding it to your combobox and setting the PromptText property on the behavior:
public class ComboBoxPromptBehavior : Behavior<ComboBox>
{
[Category("Display")]
public string PromptText
{
get { return (string)GetValue(PromptTextProperty); }
set { SetValue(PromptTextProperty, value); }
}
public static readonly DependencyProperty PromptTextProperty = DependencyProperty.Register("PromptText", typeof(string), typeof(ComboBoxPromptBehavior), new PropertyMetadata(" "));
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.Loaded += new RoutedEventHandler(AssociatedObject_Loaded);
AssociatedObject.LayoutUpdated += new EventHandler(AssociatedObject_LayoutUpdated);
}
void AssociatedObject_LayoutUpdated(object sender, EventArgs e)
{
SetPromptText();
}
protected override void OnDetaching()
{
base.OnDetaching();
AssociatedObject.Loaded -= new RoutedEventHandler(AssociatedObject_Loaded);
AssociatedObject.LayoutUpdated -= new EventHandler(AssociatedObject_LayoutUpdated);
}
void AssociatedObject_Loaded(object sender, RoutedEventArgs e)
{
SetPromptText();
}
private void SetPromptText()
{
var textbox = AssociatedObject.FindChild<TextBlock>();
if (textbox != null && string.IsNullOrWhiteSpace(textbox.Text))
{
textbox.Text = PromptText;
}
}
}
And the extension method for FindChild is:
public static T FindChild<T>(this DependencyObject element) where T : DependencyObject
{
var childCount = VisualTreeHelper.GetChildrenCount(element);
for (int i = 0; i < childCount; i++)
{
var child = VisualTreeHelper.GetChild(element, i);
if (child is T)
{
return (T)child;
}
var match = child.FindChild<T>();
if (match != null) return match;
}
return null;
}
I currently have a ListBox whose ItemsSource collection is bound to a property on my viewmodel, of type IEnumerable. When that preoprty's reference changes, the ListBox updates as expected, however I have a problem in that if I have a large collection of items and scroll to the bottom of the ListBox, and then change the reference to another collection containing, say, 1 item, the ListBox view is blank and no scrollbar is displayed. I have to then scroll the listbox up with the mouse wheel, until the 1 item comes into view.
So, what I think I'm after, is a way of resetting the scroll position of the ListBox to the top, whenever the ItemsSource property changes, so that something is always displayed no matter how large or small the collection.
I'm unable to reproduce your problem (for me, the ListBox is scrolled to the last item in the new collection when changing ItemsSource). Anyway, to scroll the ListBox to the top every time its ItemsSource changes you can use some code behind. First listen to changes in the ItemsSourceProperty and then scroll the ListBox to the top once its items has been generated
Update
Made an attached behavior that does this instead to avoid code behind. It can be used like this
<ListBox ...
behaviors:ScrollToTopBehavior.ScrollToTop="True"/>
ScrollToTopBehavior
public static class ScrollToTopBehavior
{
public static readonly DependencyProperty ScrollToTopProperty =
DependencyProperty.RegisterAttached
(
"ScrollToTop",
typeof(bool),
typeof(ScrollToTopBehavior),
new UIPropertyMetadata(false, OnScrollToTopPropertyChanged)
);
public static bool GetScrollToTop(DependencyObject obj)
{
return (bool)obj.GetValue(ScrollToTopProperty);
}
public static void SetScrollToTop(DependencyObject obj, bool value)
{
obj.SetValue(ScrollToTopProperty, value);
}
private static void OnScrollToTopPropertyChanged(DependencyObject dpo,
DependencyPropertyChangedEventArgs e)
{
ItemsControl itemsControl = dpo as ItemsControl;
if (itemsControl != null)
{
DependencyPropertyDescriptor dependencyPropertyDescriptor =
DependencyPropertyDescriptor.FromProperty(ItemsControl.ItemsSourceProperty, typeof(ItemsControl));
if (dependencyPropertyDescriptor != null)
{
if ((bool)e.NewValue == true)
{
dependencyPropertyDescriptor.AddValueChanged(itemsControl, ItemsSourceChanged);
}
else
{
dependencyPropertyDescriptor.RemoveValueChanged(itemsControl, ItemsSourceChanged);
}
}
}
}
static void ItemsSourceChanged(object sender, EventArgs e)
{
ItemsControl itemsControl = sender as ItemsControl;
EventHandler eventHandler = null;
eventHandler = new EventHandler(delegate
{
if (itemsControl.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
ScrollViewer scrollViewer = GetVisualChild<ScrollViewer>(itemsControl) as ScrollViewer;
scrollViewer.ScrollToTop();
itemsControl.ItemContainerGenerator.StatusChanged -= eventHandler;
}
});
itemsControl.ItemContainerGenerator.StatusChanged += eventHandler;
}
}
And an implementation of GetVisualChild
private T GetVisualChild<T>(DependencyObject parent) where T : Visual
{
T child = default(T);
int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < numVisuals; i++)
{
Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
child = v as T;
if (child == null)
{
child = GetVisualChild<T>(v);
}
if (child != null)
{
break;
}
}
return child;
}
Late answer:
A simple solution is to add an event handler for the TargetUpdated event, and set NotifyOnTargetUpdated=True on the ItemsSource binding:
<ListBox x:Name="listBox"
ItemsSource="{Binding MySource, NotifyOnTargetUpdated=True}"
TargetUpdated="ListBox_TargetUpdated"/>
and in the event handler, scroll to the top item:
private void ListBox_TargetUpdated(object sender, DataTransferEventArgs e)
{
if (listBox.Items.Count > 0)
{
listBox.ScrollIntoView(listBox.Items[0]);
}
}
Try this:
if (listBox.Items.Count > 0) {
listBox.ScrollIntoView(listBox.Items[0]);
}
Improved Fredrik Hedblad's answer to work with ObservableCollection:
public static class ItemsControlAttachedProperties
{
#region ScrollToTopOnItemsSourceChange Property
public static readonly DependencyProperty ScrollToTopOnItemsSourceChangeProperty =
DependencyProperty.RegisterAttached(
"ScrollToTopOnItemsSourceChange",
typeof(bool),
typeof(ItemsControlAttachedProperties),
new UIPropertyMetadata(false, OnScrollToTopOnItemsSourceChangePropertyChanged));
public static bool GetScrollToTopOnItemsSourceChange(DependencyObject obj)
{
return (bool) obj.GetValue(ScrollToTopOnItemsSourceChangeProperty);
}
public static void SetScrollToTopOnItemsSourceChange(DependencyObject obj, bool value)
{
obj.SetValue(ScrollToTopOnItemsSourceChangeProperty, value);
}
static void OnScrollToTopOnItemsSourceChangePropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
var itemsControl = obj as ItemsControl;
if (itemsControl == null)
{
throw new Exception("ScrollToTopOnItemsSourceChange Property must be attached to an ItemsControl based control.");
}
DependencyPropertyDescriptor descriptor =
DependencyPropertyDescriptor.FromProperty(ItemsControl.ItemsSourceProperty, typeof(ItemsControl));
if (descriptor != null)
{
if ((bool) e.NewValue)
{
descriptor.AddValueChanged(itemsControl, ItemsSourceChanged);
}
else
{
descriptor.RemoveValueChanged(itemsControl, ItemsSourceChanged);
}
}
}
static void ItemsSourceChanged(object sender, EventArgs e)
{
var itemsControl = sender as ItemsControl;
DoScrollToTop(itemsControl);
var collection = itemsControl.ItemsSource as INotifyCollectionChanged;
if (collection != null)
{
collection.CollectionChanged += (o, args) => DoScrollToTop(itemsControl);
}
}
static void DoScrollToTop(ItemsControl itemsControl)
{
EventHandler eventHandler = null;
eventHandler =
delegate
{
if (itemsControl.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
var scrollViewer = GetVisualChild<ScrollViewer>(itemsControl);
scrollViewer.ScrollToTop();
itemsControl.ItemContainerGenerator.StatusChanged -= eventHandler;
}
};
itemsControl.ItemContainerGenerator.StatusChanged += eventHandler;
}
static T GetVisualChild<T>(DependencyObject parent) where T : Visual
{
T child = default(T);
int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
for (var i = 0; i < numVisuals; i++)
{
var v = (Visual) VisualTreeHelper.GetChild(parent, i);
child = v as T ?? GetVisualChild<T>(v);
if (child != null)
{
break;
}
}
return child;
}
#endregion
}
When you format the control, you select a range of cells as the selection choices which are then listed in the list box. You also select a cell as the link to the selected choices in which a number will be displayed depending on the position of the selection in the list. 1 for first in the list, 2 for second etc. The code is quite simply:-
Range("A1")Select
Selection = 1
Change ("A1") to the cell you have linked
and change the 1 to the position in the list you want selected.
The cell reference being a link works both ways - if you change your selection, the number in the cell changes and if you change the number in the cell, the highlighted selection changes.
How to raise a event in usercontrol from the another usercontrol. i tried to do with delegates, but it doesnt work. How can i do this. am using C#(WPF)
usercontrol1.cs
public partial class UserControl1 : UserControl
{
delegate void myDelegate();
public UserControl1()
{
InitializeComponent();
}
private void button1_Click(object sender, RoutedEventArgs e)
{
UserControl2 obj = new UserControl2();
myDelegate d = new myDelegate(obj.CallDelegate);
obj.CallDelegate();
}
}
Usercontrol2.cs
public partial class UserControl2 : UserControl
{
public UserControl2()
{
InitializeComponent();
}
public void CallDelegate()
{
this.Width = 50;
this.Height = 50;
MessageBox.Show("Method called ");
}
}
when i use delegate i can go get the messagebox from the method, but the control doesnt resize. do i want to render it again ?? i have tried to assign explicitly, but doesnt work
In general, only the event owner can raise an event. There are exceptions to this (such as with Button.PerformClick in Windows Forms, but they have to be specifically provided by the class in question.
It's possible that WPF routed events may give an alternative here, but you haven't been clear about what kind of events you're talking about. An example of what you're trying to do would be helpful.
that's because in your code you raise an event on a new UserControl2. for your specific example the code of the UserControl1.button1_Click event should be like this:
private void button1_Click(object sender, RoutedEventArgs e)
{
if (this.Parent != null && this.Parent is StackPanel)
{
StackPanel parentControl = this.Parent as StackPanel;
foreach (UIElement child in parentControl.Children)
{
if (child is UserControl2)
((UserControl2)child).CallDelegate();
}
}
}
EDIT:
kay so it seems you want to get all the usercontrol2 within the window1 to be resized. then what you need is to make a recursive function to get the topmost parent, e.g (modded from hardcodet.net/2008/02/find-wpf-parent)
DependencyObject GetHighestParent(DependencyObject child)
{
ContentElement contentElement = child as ContentElement;
if (contentElement != null)
{
DependencyObject parent = ContentOperations.GetParent(contentElement);
if (parent != null) return parent;
FrameworkContentElement fce = contentElement as FrameworkContentElement;
return fce != null ? fce.Parent : null;
}
FrameworkElement frameworkElement = child as FrameworkElement;
if (frameworkElement != null)
{
DependencyObject parent = frameworkElement.Parent;
if (parent != null)
{
return GetHighestParent(parent);
}
else
{
return child;
}
}
DependencyObject visualParent = VisualTreeHelper.GetParent(child);
if (visualParent != null)
return GetHighestParent(visualParent);
else
return child;
}
then you might want to create a method to walkdown all the children like this:
void CallDelegateInAllControl2(DependencyObject parent)
{
int childCount = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < childCount; i++)
{
DependencyObject child = VisualTreeHelper.GetChild(parent, i);
if (child is UserControl2)
{
((UserControl2)child).CallDelegate();
}
else
{
CallDelegateInAllControl2(child);
}
}
}
and then you call it within button1_click event
private void button1_Click(object sender, RoutedEventArgs e)
{
DependencyObject parent = GetHighestParent(this);
if(parent!=null)
CallDelegateInAllControl2(parent);
}
note: a walk to get parent and child might be tricky and risky i think and i believe it's a long process so you might just want to re-layout your window1 so it has a StackPanel/Grid with a usercontrol1 element and all usercontrol2 elements within it so you can use the first code i post.