I do not know what that many parentheses and identifiers mean.
Fixing is really hard.
Please help me fix it.
Even when I could not make this change, I said that I had no paycheck.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
namespace ChatBubbles
{
public class ItemHelper : DependencyObject
{
public static readonly DependencyProperty IsCheckedProperty = DependencyProperty.RegisterAttached("IsChecked", typeof(bool?), typeof(ItemHelper), new PropertyMetadata(false, new PropertyChangedCallback(OnIsCheckedPropertyChanged)));
private static void OnIsCheckedPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (d is Family && ((bool?)e.NewValue).HasValue)
foreach (Person p in (d as Family).Members)
ItemHelper.SetIsChecked(p, (bool?)e.NewValue);
if (d is Person)
{
int checked = ((d as Person).GetValue(ItemHelper.ParentProperty) as Family).Members.Where(x => ItemHelper.GetIsChecked(x) == true).Count();
int unchecked = ((d as Person).GetValue(ItemHelper.ParentProperty) as Family).Members.Where(x => GetIsChecked(x) == false).Count();
if (unchecked > 0 && checked > 0)
{
ItemHelper.SetIsChecked((d as Person).GetValue(ItemHelper.ParentProperty) as DependencyObject, null);
return;
}
if (checked > 0)
{
ItemHelper.SetIsChecked((d as Person).GetValue(ItemHelper.ParentProperty) as DependencyObject, true);
return;
}
ItemHelper.SetIsChecked((d as Person).GetValue(ItemHelper.ParentProperty) as DependencyObject, false);
}
}
}
}
public static void SetIsChecked(DependencyObject element, bool? IsChecked)
{
element.SetValue(ItemHelper.IsCheckedProperty, IsChecked);
}
public static bool? GetIsChecked(DependencyObject element)
{
return (bool?)element.GetValue(ItemHelper.IsCheckedProperty);
}
public static readonly DependencyProperty ParentProperty = DependencyProperty.RegisterAttached("Parent", typeof(object), typeof(ItemHelper));
public static void SetParent(DependencyObject element, object Parent)
{
element.SetValue(ItemHelper.ParentProperty, Parent);
}
public static object GetParent(DependencyObject element)
{
return (object)element.GetValue(ItemHelper.ParentProperty);
}
}
}
Related
I want to create a custom class of a CommandBinding, where a RelayCommand of my ViewModel is executed when the RoutedCommand is executed.
Currently there is only the possibility to create CommandBindings which have Executed methods in the codebehind class.
Example:
<CommandBinding Command="ApplicationCommands.Close" Executed="CloseCommandHandler"
CanExecute="CanExecuteHandler"/>
This needs the CloseCommandHandler methode in the code behind.
I would want to write the following.
<CommandBinding RoutedCommand="ApplicationCommands.Close" Command={Binding Path=CloseCommand}/>
The only problem is that i can't find the bubble down and up event of the RoutedCommands.
There is no
OnPreviewCommand(object command, object commandParammeter)
OnCommand(object command, object commandParammeter)
Where is the RoutedCommand bubble down and up handled?
I came up with a solutions of my own. Its not the most beautiful, but its working.
I derived from the ContentControl. The new Control has a RoutedCommandBindings property, which contains a list of "sort of" CommandBindings between RoutedCommands and RelayCommands.
It can be used like this.
<CSControls:RoutedCommandBinder>
<CSControls:RoutedCommandBinder.RoutedCommandBindings>
<CSControls:RoutedCommandBindingCollection>
<CSControls:RoutedCommandBinding RoutedCommand="{x:Static ApplicationCommands.New}" Command="{Binding Path=AddInstanceCommand}"/>
</CSControls:RoutedCommandBindingCollection>
</CSControls:RoutedCommandBinder.RoutedCommandBindings>
<CSControls:RoutedCommandBinder.Content>
<!-- Every RoutedCommand of type ApplicationCommands.New will execute the binded RelayCommand "AddInstanceCommand-->
</CSControls:RoutedCommandBinder.Content>
</CSControls:RoutedCommandBinder>
Here is the CustomControl code.
public class RoutedCommandBinder : ContentControl
{
public RoutedCommandBinder()
{
this.DataContextChanged += RoutedCommandBinder_DataContextChanged;
}
public static readonly DependencyProperty RoutedCommandBindingsProperty = DependencyProperty.Register("RoutedCommandBindings", typeof(RoutedCommandBindingCollection), typeof(RoutedCommandBinder), new PropertyMetadata(new RoutedCommandBindingCollection(), OnRoutedCommandBindingsChanged));
public RoutedCommandBindingCollection RoutedCommandBindings
{
get { return (RoutedCommandBindingCollection)this.GetValue(RoutedCommandBindingsProperty); }
set { SetValue(RoutedCommandBindingsProperty, value); }
}
private static void OnRoutedCommandBindingsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
RoutedCommandBinder binder = (RoutedCommandBinder)d;
binder.CommandBindings.Clear();
SetDataContextForCommandBindings(binder);
if (e.NewValue != null)
{
RoutedCommandBindingCollection bindings = (RoutedCommandBindingCollection)e.NewValue;
foreach (RoutedCommandBinding binding in bindings)
{
binder.CommandBindings.Add(new CommandBinding(binding.RoutedCommand, binder.RoutedCommandExecuted, binder.CanExecuteRoutedEventHandler));
}
}
}
private void RoutedCommandBinder_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
SetDataContextForCommandBindings(this);
}
private static void SetDataContextForCommandBindings(RoutedCommandBinder binder)
{
if (binder.DataContext != null && binder.RoutedCommandBindings != null)
{
foreach (RoutedCommandBinding binding in binder.RoutedCommandBindings)
{
binding.DataContext = binder.DataContext;
}
}
}
private void RoutedCommandExecuted(object sender, ExecutedRoutedEventArgs e)
{
RoutedCommandBinding binding = this.RoutedCommandBindings.FirstOrDefault(t => t.RoutedCommand == e.Command);
if (binding != null)
{
binding.Command.Execute(e.Parameter);
}
}
private void CanExecuteRoutedEventHandler(object sender, CanExecuteRoutedEventArgs e)
{
RoutedCommandBinding binding = this.RoutedCommandBindings.FirstOrDefault(t => t.RoutedCommand == e.Command);
if (binding != null)
{
e.CanExecute = binding.Command.CanExecute(e.Parameter);
}
}
}
public class RoutedCommandBindingCollection : List<RoutedCommandBinding>
{
}
public class RoutedCommandBinding : FrameworkElement
{
public static readonly DependencyProperty CommandProperty = DependencyProperty.Register("Command", typeof(ICommand), typeof(RoutedCommandBinding), new PropertyMetadata(null));
public ICommand Command
{
get { return (ICommand)this.GetValue(CommandProperty); }
set { SetValue(CommandProperty, value); }
}
public static readonly DependencyProperty RoutedCommandProperty = DependencyProperty.Register("RoutedCommand", typeof(RoutedCommand), typeof(RoutedCommandBinding), new PropertyMetadata(null));
public RoutedCommand RoutedCommand
{
get { return (RoutedCommand)this.GetValue(RoutedCommandProperty); }
set { SetValue(RoutedCommandProperty, value); }
}
}
I am using Phone7.Fx R1
The following works. The system does not react when a user presses the button. This means, than there is no reaction if Stop Game is pressed without a game has been started and vice versa.
However the button looks active. I am aware that I can bind the IsEnabled to a different property, but I would like it to bind to NewGameCanExecute and StopGameCanExecute. Is this possible?
Some XAML code:
<Preview:BindableApplicationBarIconButton Command="{Binding NewGame}" IconUri="/images/icons/appbar.add.rest.png" Text="New game" />
<Preview:BindableApplicationBarIconButton Command="{Binding StopGame}" IconUri="/images/icons/appbar.stop.rest.png" Text="Stop game" />
And the relay commands:
public RelayCommand NewGame { get; private set; }
public RelayCommand StopGame { get; private set; }
//Constructor
NewGame = new RelayCommand(NewGameExecute, NewGameCanExecute);
StopGame = new RelayCommand(StopGameExecute, StopGameCanExecute);
void NewGameExecute()
{
_gameStarted = true;
_gameControlModel.StartNewGame();
StopGame.RaiseCanExecuteChanged();
}
bool NewGameCanExecute()
{
return !_gameStarted;
}
void StopGameExecute()
{
_gameControlModel.StopGame();
_gameStarted = false;
NewGame.RaiseCanExecuteChanged();
}
bool StopGameCanExecute()
{
return _gameStarted;
}
Couple of questions and answers:
Q: Have you tried to set a breakpoint in the CanExecute functions to see if it gets called?
A: Yes. It does get called, but the icon is not grayed out, eventhough false is returned.
The Execute method is not executed, if the CanExecute method returns false. But I want the icon to be grayed out like a normal button.
SOLUTION
I spend some time and came up with a solution, which can be found here:
http://pastebin.com/MM75xACj
This is obviously a bug in whatever BindableApplicationBarIconButton implementation you're using.
Ask the author of it for help, or debug your 3rd party software yourself.
SOLUTION
I spend some time and came up with a solution and edited the applicationbariconbutton class.
namespace Phone7.Fx.Controls
{
public class BindableApplicationBarIconButton : FrameworkElement, IApplicationBarIconButton
{
public int Index { get; set; }
public static DependencyProperty CommandProperty = DependencyProperty.RegisterAttached("Command", typeof(ICommand), typeof(BindableApplicationBarIconButton), new PropertyMetadata(null, OnCommandPropertyChanged));
private static void OnCommandPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue != e.OldValue)
{
((BindableApplicationBarIconButton)d).Command = (ICommand)e.NewValue;
}
}
public ICommand Command
{
get { return (ICommand)GetValue(CommandProperty); }
set {
Command.CanExecuteChanged -= ValueOnCanExecuteChanged;
SetValue(CommandProperty, value);
Command.CanExecuteChanged += ValueOnCanExecuteChanged;
}
}
private void ValueOnCanExecuteChanged(object sender, EventArgs eventArgs)
{
ICommand commandSender = sender as ICommand;
if(commandSender != null)
{IsEnabled = commandSender.CanExecute(null);}
}
public static readonly DependencyProperty CommandParameterProperty =
DependencyProperty.RegisterAttached("CommandParameter", typeof(object), typeof(BindableApplicationBarIconButton), new PropertyMetadata(null, OnCommandParameterPropertyChanged));
private static void OnCommandParameterPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var invokeCommand = d as BindableApplicationBarIconButton;
if (invokeCommand != null)
{
invokeCommand.SetValue(CommandParameterProperty, e.NewValue);
}
}
public object CommandParameter
{
get { return GetValue(CommandParameterProperty); }
set
{
SetValue(CommandParameterProperty, value);
}
}
public static readonly DependencyProperty CommandParameterValueProperty =
DependencyProperty.RegisterAttached("CommandParameterValue", typeof(object), typeof(BindableApplicationBarIconButton), null);
public object CommandParameterValue
{
get
{
var returnValue = GetValue(CommandParameterValueProperty);
return returnValue;
}
set { SetValue(CommandParameterValueProperty, value); }
}
public static readonly DependencyProperty IsEnabledProperty =
DependencyProperty.RegisterAttached("IsEnabled", typeof(bool), typeof(BindableApplicationBarIconButton), new PropertyMetadata(true, OnEnabledChanged));
private static void OnEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue != e.OldValue)
{
((BindableApplicationBarIconButton)d).Button.IsEnabled = (bool)e.NewValue;
}
}
public static readonly DependencyProperty TextProperty =
DependencyProperty.RegisterAttached("Text", typeof(string), typeof(BindableApplicationBarIconButton), new PropertyMetadata(OnTextChanged));
public new static readonly DependencyProperty VisibilityProperty =
DependencyProperty.RegisterAttached("Visibility", typeof(Visibility), typeof(BindableApplicationBarIconButton), new PropertyMetadata(OnVisibilityChanged));
private static void OnVisibilityChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue != e.OldValue)
{
var button = ((BindableApplicationBarIconButton)d);
BindableApplicationBar bar = button.Parent as BindableApplicationBar;
bar.Invalidate();
}
}
public new Visibility Visibility
{
get { return (Visibility)GetValue(VisibilityProperty); }
set { SetValue(VisibilityProperty, value); }
}
private static void OnTextChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue != e.OldValue)
{
((BindableApplicationBarIconButton)d).Button.Text = e.NewValue.ToString();
}
}
public ApplicationBarIconButton Button { get; set; }
public BindableApplicationBarIconButton()
{
Button = new ApplicationBarIconButton();
Button.Text = "Text";
Button.Click += ApplicationBarIconButtonClick;
}
void ApplicationBarIconButtonClick(object sender, EventArgs e)
{
if (Command != null && CommandParameter != null)
Command.Execute(CommandParameter);
else if (Command != null)
Command.Execute(CommandParameterValue);
if (Click != null)
Click(this, e);
}
public bool IsEnabled
{
get { return (bool)GetValue(IsEnabledProperty); }
set { SetValue(IsEnabledProperty, value); }
}
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public event EventHandler Click;
public Uri IconUri
{
get { return Button.IconUri; }
set { Button.IconUri = value; }
}
}
I Create a TimeInput Control Like to Enter Time.
<TextBox Text="{Binding Path=Hours}" />
<TextBox IsReadOnly="True"
Focusable="False"
Text=":" />
<TextBox Text="{Binding Path=Minutes}" />
and
public int Hours {
get { return (int)this.GetValue(HoursProperty); }
set {
this.SetValue(HoursProperty, value);
this.OnPropertyChanged("Hours");
}
}
public static readonly DependencyProperty HoursProperty =
DependencyProperty.Register("Hours", typeof(int), typeof(UserControl1), new UIPropertyMetadata(0, new PropertyChangedCallback(OnHoursChanged)));
private static void OnHoursChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e) {
if (obj != null) {
int newValue = (int)e.NewValue;
}
}
public int Minutes {
get { return (int)this.GetValue(MinutesProperty); }
set {
this.SetValue(MinutesProperty, value);
this.OnPropertyChanged("Minutes");
}
}
// Using a DependencyProperty as the backing store for Minutes. This enables animation, styling, binding, etc...
public static readonly DependencyProperty MinutesProperty =
DependencyProperty.Register("Minutes", typeof(int), typeof(UserControl1), new UIPropertyMetadata(0, new PropertyChangedCallback(OnMinutesChanged)));
private static void OnMinutesChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e) {
if (obj != null) {
int newValue = (int)e.NewValue;
}
}
public Nullable<TimeSpan> Value {
get { return (Nullable<TimeSpan>)this.GetValue(ValueProperty); }
set {
this.SetValue(ValueProperty, value);
this.OnPropertyChanged("Value");
}
}
// Using a DependencyProperty as the backing store for Value. This enables animation, styling, binding, etc...
public static readonly DependencyProperty ValueProperty =
DependencyProperty.Register("Value", typeof(Nullable<TimeSpan>), typeof(UserControl1), new UIPropertyMetadata(null, new PropertyChangedCallback(OnValueChanged)));
private static void OnValueChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e) {
if (obj != null) {
(obj as UserControl1).UpdateTime(e.NewValue as TimeSpan?);
}
}
public void UpdateTime(TimeSpan? newTimeSpan) {
if (newTimeSpan.HasValue) {
this.Hours = newTimeSpan.Value.Hours;
this.Minutes = newTimeSpan.Value.Minutes;
}
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged(string name) {
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null) {
handler(this, new PropertyChangedEventArgs(name));
}
}
#endregion
While I use this on another UserControl and Bind to a Property It doesn't work and show values.
I use it like this:
<uc:UserControl1 Value="{Binding StartTime}"/>
and
public TimeSpan StartTime
{
get { return new Types.Time(Item.StartTime).ToTimeSpan(); }
set { Item.StartTime = new Types.Time(value).ToShort(); NotifyPropertyChanged("StartTime"); }
}
That Item is an entity read from database and bind and StartTime is short form of hhmm.
i have updated your code, with dependency properties you don't need fire the property changed event explicit.
public partial class UserControl1 : UserControl
{
public UserControl1() {
this.InitializeComponent();
}
public int Hours {
get { return (int)this.GetValue(HoursProperty); }
set { this.SetValue(HoursProperty, value); }
}
public static readonly DependencyProperty HoursProperty =
DependencyProperty.Register("Hours", typeof(int), typeof(UserControl1), new UIPropertyMetadata(0, new PropertyChangedCallback(OnHoursChanged)));
private static void OnHoursChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e) {
var uc = obj as UserControl1;
if (uc != null && e.NewValue != e.OldValue) {
int newValue = (int)e.NewValue;
uc.TimeValue = new TimeSpan(newValue, uc.Minutes, 0);
}
}
public int Minutes {
get { return (int)this.GetValue(MinutesProperty); }
set { this.SetValue(MinutesProperty, value); }
}
// Using a DependencyProperty as the backing store for Minutes. This enables animation, styling, binding, etc...
public static readonly DependencyProperty MinutesProperty =
DependencyProperty.Register("Minutes", typeof(int), typeof(UserControl1), new UIPropertyMetadata(0, new PropertyChangedCallback(OnMinutesChanged)));
private static void OnMinutesChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e) {
var uc = obj as UserControl1;
if (uc != null && e.NewValue != e.OldValue) {
int newValue = (int)e.NewValue;
uc.TimeValue = new TimeSpan(uc.Hours, newValue, 0);
}
}
public Nullable<TimeSpan> TimeValue {
get { return (Nullable<TimeSpan>)this.GetValue(ValueProperty); }
set { this.SetValue(ValueProperty, value); }
}
public static readonly DependencyProperty ValueProperty =
DependencyProperty.Register("TimeValue", typeof(Nullable<TimeSpan>), typeof(UserControl1), new UIPropertyMetadata(null, new PropertyChangedCallback(OnValueChanged)));
private static void OnValueChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e) {
var uc = obj as UserControl1;
if (uc != null && e.NewValue != e.OldValue) {
uc.UpdateTime(e.NewValue as TimeSpan?);
}
}
public void UpdateTime(TimeSpan? newTimeSpan) {
if (newTimeSpan.HasValue) {
this.Hours = newTimeSpan.Value.Hours;
this.Minutes = newTimeSpan.Value.Minutes;
}
}
}
second, i think you use the StartTime property incorrect, use it as dependency property too, or implement INotifyPropertyChanged.
{
// .....
StartTime = new Types.Time(this.Item.StartTime).ToTimeSpan();
// .....
}
public static readonly DependencyProperty StartTimeProperty =
DependencyProperty.Register("StartTime", typeof(TimeSpan?), typeof(Window1), new PropertyMetadata(default(TimeSpan?), new PropertyChangedCallback(OnStartTimePropertyChanged)));
private static void OnStartTimePropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e) {
if(e.NewValue != e.OldValue) {
(dependencyObject as Window1).Item.StartTime = new Types.Time(e.NewValue).ToShort();
}
}
public TimeSpan? StartTime {
get { return (TimeSpan?)GetValue(StartTimeProperty); }
set { SetValue(StartTimeProperty, value); }
}
hope this helps
You should not have any other code then calling GetValue and SetValue inside getter and setter of dependency property. But this may not resolve you problem. If you want to call some code when value change then do that inside callback method instead of setter.
I want to write a custom FrameworkElement which host Visuals. My first attempt was to create an instance of ContainerVisual and write a wrapper property for ContainerVisual.Children and then set it as ContentProperty so I can and Visuals via XAML. But VisualCollection does only implement ICollection and not IList or any supported interface and VisualCollection is selead so I can't implement IList on my own.
How can I hostvisuals and let them add declaratively using XAML?
Okay, long time ago but here is the solution I found that time back...
The Collection:
Note the hack comments.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Media;
using System.Collections.ObjectModel;
using WPF.Controls.Primitives;
namespace WPF.Controls.Core
{
public class PrimitiveCollection : ObservableCollection<Primitive>
{
protected PrimitiveContainerVisual _owner;
public PrimitiveCollection(PrimitiveContainerVisual owner)
: base()
{
if (owner == null)
throw new ArgumentNullException("owner");
_owner = owner;
}
protected override void ClearItems()
{
foreach (var item in this)
{
item.IsDirtyChanged -= new IsDirtyChangedHandler(item_IsDirtyChanged);
_owner.InternalRemoveVisualChild(item);
}
base.ClearItems();
}
protected override void InsertItem(int index, Primitive item)
{
if (item != null && item.Parent != null)
throw new ArgumentNullException("Visual has parent");
item.IsDirtyChanged += new IsDirtyChangedHandler(item_IsDirtyChanged);
_owner.InternalAddVisualChild(item);
base.InsertItem(index, item);
}
protected override void RemoveItem(int index)
{
Primitive item = this[index];
item.IsDirtyChanged -= new IsDirtyChangedHandler(item_IsDirtyChanged);
_owner.InternalRemoveVisualChild(item);
base.RemoveItem(index);
}
protected override void OnPropertyChanged(System.ComponentModel.PropertyChangedEventArgs e)
{
base.OnPropertyChanged(e);
}
void item_IsDirtyChanged(object sender, PrimitiveChangedEventArgs e)
{
if(e.IsDirty)
_owner.RequestRedraw();
}
}
}
And the Control which you can use in XAML
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Media;
using WPF.Controls.Primitives;
using System.Windows;
using System.Reflection;
namespace WPF.Controls.Core
{
public class PrimitiveContainerVisual : Visual
{
private PrimitiveCollection _primitives;
private PropertyInfo _contentBoundsPropInfo;
private PropertyInfo _descendantBoundsPropInfo;
public PrimitiveCollection Children
{
get { return _primitives; }
set { _primitives = value; }
}
public Rect ContentBounds
{
// HACK access internal property of Visual
get { return (Rect)_contentBoundsPropInfo.GetValue(this, null); }
}
public Rect DescendantBounds
{
// HACK access internal property of Visual
get { return (Rect)_descendantBoundsPropInfo.GetValue(this, null); }
}
public PrimitiveContainerVisual()
{
_primitives = new PrimitiveCollection(this);
Type thisType = this.GetType();
BindingFlags flags = BindingFlags.NonPublic | BindingFlags.Instance;
_contentBoundsPropInfo = thisType.GetProperty("VisualContentBounds", flags);
_descendantBoundsPropInfo = thisType.GetProperty("VisualDescendantBounds", flags);
}
internal void InternalAddVisualChild(Primitive prim)
{
this.AddVisualChild(prim);
}
internal void InternalRemoveVisualChild(Primitive prim)
{
this.RemoveVisualChild(prim);
}
public bool RequestRedraw()
{
UIElement uiParent = VisualParent as UIElement;
if (uiParent != null)
{
uiParent.InvalidateVisual();
return true;
}
else
return false;
}
}
}
I'm trying to write a panel class from this two resources:
WPF: how to make the (0,0) in center inside a Canvas
http://www.codeproject.com/KB/WPF/DraggingElementsInCanvas.aspx
The panel class will have two attached properties "X" and "Y" and if any element gives x and y to be zero then it will be placed on the center of the Panel. The panel will also let the user to drag things around . Please help me write this class. I'm very new to WPF.
This is how far I've come. Now I tried to implement this but its not working, if you can help me implement the GetTop,GetLeft,GetBottom,GetRight functions which are not by default defined in panel class and which are neccessary. If these 4 methods are present then dragging functions can be implemented here.
using System;
using System.Linq;
using System.Windows;
using System.ComponentModel;
using System.Windows.Controls;
using System.Windows.Media;
namespace SmartERP.Elements
{
public class SmartCanvas : Panel
{
public static readonly DependencyProperty TopProperty;
public static readonly DependencyProperty LeftProperty;
public static readonly DependencyProperty BottomProperty;
public static readonly DependencyProperty RightProperty;
static SmartCanvas()
{
TopProperty = DependencyProperty.Register("Top", typeof(double), typeof(SmartCanvas), new PropertyMetadata(0.0));
LeftProperty = DependencyProperty.Register("Left", typeof(double), typeof(SmartCanvas), new PropertyMetadata(0.0));
BottomProperty = DependencyProperty.Register("Bottom", typeof(double), typeof(SmartCanvas), new PropertyMetadata(0.0));
RightProperty = DependencyProperty.Register("Right", typeof(double), typeof(SmartCanvas), new PropertyMetadata(0.0));
}
public double Top
{
get { return (double)base.GetValue(TopProperty); }
set { base.SetValue(TopProperty, value); }
}
public double Bottom
{
get { return (double)base.GetValue(BottomProperty); }
set { base.SetValue(BottomProperty, value); }
}
public double Left
{
get { return (double)base.GetValue(LeftProperty); }
set { base.SetValue(LeftProperty, value); }
}
public double Right
{
get { return (double)base.GetValue(RightProperty); }
set { base.SetValue(RightProperty, value); }
}
private double GetTop(UIElement element)
{
return (double)this.GetValue(TopProperty);
}
private double GetLeft(UIElement element)
{
return (double)this.GetValue(LeftProperty);
}
private double GetBottom(UIElement element)
{
return (double)this.GetValue(BottomProperty);
}
private double GetRight(UIElement element)
{
return (double)this.GetValue(RightProperty);
}
protected override Size ArrangeOverride(Size arrangeSize)
{
Point middle = new Point(arrangeSize.Width / 2, arrangeSize.Height / 2);
foreach (UIElement element in base.InternalChildren)
{
if (element == null)
{
continue;
}
double x = 0.0;
double y = 0.0;
double left = GetLeft(element);
if (!double.IsNaN(left))
{
x = left;
}
double top = GetTop(element);
if (!double.IsNaN(top))
{
y = top;
}
element.Arrange(new Rect(new Point(middle.X + x, middle.Y + y), element.DesiredSize));
}
return arrangeSize;
}
}
}
The panel class will have two attached properties "X" and "Y" [...]
OK, then you should implement those attached properties. See the example in Section Custom Attached Properties of the Attached Properties Overview on MSDN. Here's how this would look for X:
public static readonly DependencyProperty XProperty =
DependencyProperty.RegisterAttached("X", typeof(double),
typeof(SmartCanvas), new FrameworkPropertyMetadata(0.0));
public static void SetX(UIElement element, double value) { element.SetValue(XProperty, value); }
public static double GetX(UIElement element) { return (double)element.GetValue(XProperty); }
Once you have done this, you have GetX and GetY, which is probably what you mean by GetTop and GetLeft.