WPF custom shader effect property binding for animation - wpf

I'm implementing transitions in a WPF application.
First I "save" my 2 FrameworkElement in 2 ImageBrush.
Then I set the Input & Back (Brush) properties of my shader Effect with them.
CustomEffect s = new CustomEffect();
RenderTargetBitmap rtb = new RenderTargetBitmap((int)SourceFrameWorkElement.ActualWidth, (int)SourceFrameWorkElement.ActualHeight, 96, 96, PixelFormats.Pbgra32);
rtb.Render(SourceFrameWorkElement);
ImageBrush ib = new ImageBrush(rtb);
s.Input = ib;
rtb.Render(TargetFrameWorkElement);
ib.ImageSource = rtb;
s.Back = ib;
SourceFrameWorkElement.Effect = s;
Now that all is set up, I want to animate the Time property of my shader, and i've tried this:
DoubleAnimation refDoubleAnimation = new DoubleAnimation(0.0, 1.0, Duration);
Storyboard.SetTarget(refDoubleAnimation, SourceFrameWorkElement);
Storyboard.SetTargetProperty(refDoubleAnimation, new PropertyPath("(Effect).(CustomEffect.Time)");
refStoryboard.Children.Add(refDoubleAnimation);
refStoryboard.Completed += new EventHandler(OnStoryboardCompleted);
refStoryboard.Begin(SourceFrameWorkElement, true);
and i get an InvalidOperationException on the begin method with this message:
"Cannot resolve all property references in the property path '(Effect).(CustomEffect.Time)'.
Verify that applicable objects supports the properties."
But when I use a built in Effect like BlurEffect, it works....
Can someone tell me where i'm wrong ?
Edit:
I've also tried
SourceElement.Effect.BeginAnimation(SlideInEffect.TimeProperty, refDoubleAnimation)
instead of using the storyboard, I don't get an exception but the second image pop instantly and the animation is not playing

The solution was to use BeginAnimation ^^
In fact, I had the second image with opacity to 1, and the animation was playing behind
(i checked if the time elapsed to get in my OnAnimationCompleted eventHandler matched with the transition Duration)
so i've created a second animation on the TargetElement opacity with 2 DiscreteDoubleKeyFrames to do the trick and now it works ^^
Maybe the Storyboard thing could work if i add the namespace in the PropertyPath but i have no time to test it so give it a try if you want, and update the post ^^.

Related

How to add borders to WPF ListView in code

I have created a ListView with a GridView in code.
ListView gridList = new ListView();
GridView gridListView = new GridView ();
gridList.View = gridListView;
Now, I define a GridViewColumn, set the header, width and bindingPath. All good and the data shows up.
GridViewColumn listColumn = new GridViewColumn();
listColumn.Header = "Some Header";
listColumn.Width = 100.0;
listColumn.DisplayMemeberBinding = new Binding("Name");
gridListView.Columns.Add(listColumn);
But there are no borders/gridlines shown on display of this ListView. How can I add borders through code?
Someone described my exact problem here but no good solution mentioned
http://social.msdn.microsoft.com/Forums/en-US/fa4fa8e0-81fe-487a-8763-590062d29c06/wpf-listview-gridview-row-border?forum=wpf
The logic in WPF programming is totally different from what you've done in winforms. Everything related to UI should always be set up using XAML (as much as possible). The WPF library itself has many parts desgined mainly for use in XAML although there is always an equivalent codebehind. However that's when using codebehind may be awkward and non-intuitive (as well as straight-forward).
I understand that you want something like the ListView Grid in Winforms. In WPF that can be achieved easily if you use XAML code. Even in code behind, you can always build a Style or Template from XAML string (with the help of XamlReader). This approach is good for complex scenario but in this case I have another approach (don't use the XAML parser at all). This trick does render the grid which is good enough (and at best it can do for the trade-off of simplicity):
//we need an instance of Style to set to ListView.ItemContainerStyle
var style = new Style(typeof(ListViewItem));
//set the bottom border thickness to 1
var setter = new Setter(Control.BorderThickness, new Thickness(0,0,0,1));
style.Setters.Add(setter);
//set the border brush
var borderBrush = new LinearGradientBrush { StartPoint = new Point(0,0),
EndPoint = new Point(1,0)};
var gradStop = new GradientStop(Colors.Transparent, 0.001);
borderBrush.GradientStops.Add(gradStop);
gradStop = new GradientStop(Colors.Green, 0.001);
borderBrush.GradientStops.Add(gradStop);
gradStop = new GradientStop(Colors.Green, 0.999);
borderBrush.GradientStops.Add(gradStop);
gradStop = new GradientStop(Colors.Transparent, 0.999);
borderBrush.GradientStops.Add(gradStop);
setter = new Setter(Control.BorderBrush, borderBrush);
style.Setters.Add(setter);
yourListView.ItemContainerStyle = style;
Note that the default inner Border of each ListViewItem has a hard-coded CornerRadius of about 2, so by setting just the bottom BorderBrush to a solid brush such as Brushes.Green will show a little upwards curly line at the 2 ends of the bottom border. You can try it yourself. If this result is acceptable, the code can be shorter and simpler (because you don't have to define the GradientBrush to cut-off the 2 curly ends) like this:
setter = new Setter(Control.BorderBrush, Brushes.Green);
style.Setters.Add(setter);
If the behavior is still not what you want. You should try the approach I mentioned about using XamlReader to parse a XAML string and get an instance of whatever you want in codebehind. (you can search it yourself, it's easy to have some result).
I suggest you see this link, it contains a dynamic GridView created in code-behind that can be useful for your specific case. For the code sample that you provided, you didn't add ShowGridLines property.

resizing dockpanel after animation, VB

I resize a dock panel like this:
Private WithEvents PanelAnimation As New DoubleAnimation
Private WithEvents PanelSB As New Storyboard
With PanelAnimation
.From = WpfDockPanel.ActualHeight
.To = s
.Duration = New Duration(TimeSpan.FromSeconds(0.5))
.AccelerationRatio = 0.5
.DecelerationRatio = 0.5
End With
PanelSB.Children.Add(PanelAnimation)
Storyboard.SetTarget(PanelAnimation, WpfDockPanel)
Storyboard.SetTargetProperty(PanelAnimation, New PropertyPath(DockPanel.HeightProperty))
PanelSB.Begin(AviMainWindow)
..which works fine. Then, I want to manually set the size, but it won't change, if I stop the code and type in a different size, the size won't change, it is as though it is readonly.
But if I change the size once, not by animating, just by setting the size, I can change it again no problem. Why can't I manually set the height after animating?
Thanks
This is because the animation's FillBehavior is set to HoldEnd by default. You could set it to Stop.
You would however also have to set the Height property of the animation target to the desired end value manually before starting the animation. Otherwise it would flip back to the value it had before the animation was started.
With PanelAnimation
.FillBehavior = FillBehavior.Stop
...
...
WpfDockPanel.Height = s
PanelSB.Begin(AviMainWindow)
Probably you need to remove the value applied by the animation. Something like
WpfDockPanel.BeginAnimation(DockPanel.HeightProperty, null)
should do the trick.

Visual brush using control which isn't rendered?

I'm playing around with an idea at the moment and I've hit a brick wall. I'm using a console app to create a visual control (DevExpress chartcontrol to be precise) in memory, I'm then trying to save that control to an image using a VisualBrush but it won't work because (I assume) the control isn't drawn to the screen.
I've put my code in below so you know where I am at the moment. Does anyone know how I could possibly save this control to an image (ideally jpg, but anything will do...) using a console app? I really don't want to have to render it to the screen even for a millisecond just to be able to save it...
static void sl_CreateDetail(FrameworkElement chartControl1, CreateAreaEventArgs e)
{
var brush = new VisualBrush(chartControl1);
var visual = new DrawingVisual();
DrawingContext context = visual.RenderOpen();
context.DrawRectangle(brush, null,
new Rect(0, 0, chartControl1.ActualWidth, chartControl1.ActualHeight));
context.Close();
var bmp = new RenderTargetBitmap((int)chartControl1.ActualWidth,
(int)chartControl1.ActualHeight, 96, 96, PixelFormats.Pbgra32);
bmp.Render(visual);
e.Data = bmp;
}
Before rendering the control you would have to manually do its layout by calling Measure and Arrange. This requires that you specify the desired size of the control, e.g. by explicitly setting its Width and Height properties.
There is no need for VisualBrush and DrawingVisual, you can directly render the control to the RenderTargetBitmap.
chartControl1.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
chartControl1.Arrange(new Rect(0, 0, chartControl1.Width, chartControl1.Height));
chartControl1.UpdateLayout();
var bmp = new RenderTargetBitmap((int)chartControl1.ActualWidth,
(int)chartControl1.ActualHeight, 96, 96, PixelFormats.Pbgra32);
bmp.Render(chartControl1);
If the control calculates a preferred size during layout (in Measure), you could perhaps use its DesiredSize property for rendering.
chartControl1.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
chartControl1.Arrange(new Rect(new Point(), chartControl1.DesiredSize));
chartControl1.UpdateLayout();
Note also that the rendering thread's ApartmentState must be STA. In a console application you could simply apply the STAThread attribute to the Main method.
[STAThread]
static void Main(string[] args)
{
...
}
I tried Measure(), Arrange(), etc, then discovered that these DO work if the Visual has a parent! In my case I was removing the Visual from one container, updating its properties (colour, etc), then trying to use it as a VisualBrush and it wasn't getting updated. Leaving it in the original container for the duration of Measure() and Arrange() fixed it (even though it was all done offscreen).

WPF animation problem when using Storyboard from code

I'm working on a 3D carousel of flat, square tiles that will contain information. I'm working on animating this carousel to rotate when a person presses Next and Previous buttons.
I've gotten it to work by using BeginAnimation on the Rotation property of the RotateTransform3D I applied to the carousel, but I can't seem to make a Storyboard version of the same animation work. The reason I need the Storyboard version is for the HandOffBehavior.Compose parameter because without it, multiple clicks of my next and previous buttons results in a misaligned carousel.
Here is the code for the Storyboard:
RotateTransform3D tempTransform = (RotateTransform3D)wheel.Transform;
AxisAngleRotation3D rotation = (AxisAngleRotation3D)tempTransform.Rotation;
Storyboard storyboard = new Storyboard();
DoubleAnimation animation = new DoubleAnimation();
animation.By = defaultAngle;
animation.Duration = TimeSpan.FromSeconds(.5);
Storyboard.SetTarget(animation, rotation);
Storyboard.SetTargetProperty(animation, new PropertyPath("Angle"));
storyboard.Children.Add(animation);
storyboard.Duration = animation.Duration;
storyboard.Begin(new FrameworkContentElement(), HandoffBehavior.Compose);
For some reason, this code results in absolutely nothing. I followed the examples I had to the letter, so I am quite frustrated. Any help is greatly appreciated. I am also completely open to using BeginAnimation if I can replicate HandOffBehavior.Compose.
My experience comes from 2D animation, but I guess the problem is the same.
For some stupid reason (probably relating to an unhealthy focus on XAML), Storyboards can only animate Freezable objects by looking them up by name. (See example in Storyboards Overview.) Thus although you provide a reference to your 'rotation' object when you call Storyboard.SetTarget(animation, rotation), the Storyboard only wants to remember and use a name, which it does not have.
The solution is:
Create a naming scope around the element that will govern the transform.
Call RegisterName() for each Freezable object being animated.
Pass the element to Storyboard.Begin()
Which would make your code look something like this (not tested):
FrameworkContentElement element = new FrameworkContentElement();
NameScope.SetNameScope(element, new NameScope());
RotateTransform3D tempTransform = (RotateTransform3D)wheel.Transform;
AxisAngleRotation3D rotation = (AxisAngleRotation3D)tempTransform.Rotation;
element.RegisterName("rotation", rotation);
Storyboard storyboard = new Storyboard();
DoubleAnimation animation = new DoubleAnimation();
animation.By = defaultAngle;
animation.Duration = TimeSpan.FromSeconds(.5);
Storyboard.SetTarget(animation, rotation);
Storyboard.SetTargetProperty(animation, new PropertyPath("Angle"));
storyboard.Children.Add(animation);
storyboard.Duration = animation.Duration;
storyboard.Begin(element, HandoffBehavior.Compose);
None of this is necessary in XAML because your objects are automatically registered.
EDIT: But then I worked out that you can simplify things by leaving out the Storyboard altogether:
var T = new TranslateTransform(40, 0);
Duration duration = new Duration(new TimeSpan(0, 0, 0, 1, 0);
DoubleAnimation anim = new DoubleAnimation(30, duration);
T.BeginAnimation(TranslateTransform.YProperty, anim);

Silverlight Image Data Binding

I am new to Silverlight, and have an issue with binding.
I have a class ItemsManager, that has inside its scope another class Item.
class ItemsManager
{
...
class Item : INotifyPropertyChanged
{
...
private BitmapImage bitmapSource;
public BitmapImage BitmapSource
{
get { return bitmapSource; }
set
{
bitmapSource = value;
if(PropertyChanged != null )PropertyChanged("BitmapSource")
}
}
}
}
I do the following in code to test binding:
{
ItemsManager.Instance.AddItem("123");
//Items manager started downloading item visual
//part (in my case bitmap image png)
Binding b = new Binding("Source");
b.Source = ItemsManager.Instance.GetItem("123").BitmapSource;
b.BindsDirectlyToSource = true;
Image img = new Image();
img.SetBinding(Image.SourceProperty, b);
img.Width = (double)100.0;
img.Height = (double)100.0;
LayoutRoot.Children.Add(img);
}
Once image is loaded, image doesn't appear. Though, if I set directly after image has been loaded its source, it displays well.
I also noticed that PropertyChanged("BitmapSource") never fires, because PropertyChanged is null, like Image never binded to it.
I am looking forward to hearing from you!
PropertyChanged("BitmapSource") fires in case of two-way binding.
I.e. if you use two way binding and then manually change image source, like
img.Source = new BitmapImage(new Uri("http://...."));
the property changed event would fire.
As for the image appearance, it seems you bind data in wrong way.
Try declarative bindings.
There are several things wrong with this code:-
You've bound directly to the BitmapImage exposed by the BitmapSource property so you've taken your nested Item class out of the picture anyway.
Also for the property setter to be called you would need something to assign a value to the Image elements Source property and your binding would need to be in two way mode.
Your binding object creation is confused, it specifies a path (which is wrong anyway) but then binds direct to source.
Hence your code would need to look like this:-
Binding b = new Binding("BitmapSource");
b.Source = ItemsManager.Instance.GetItem("123");
b.Mode = BindingMode.TwoWay;
Now when a new BitmapImage is assigned the Image Source property your setter code should run. However it should be born in mind that the this property is of the more general type ImageSource. Hence this code will break if another derivative of ImageSource is assigned instead.
One other thing which may be a problem, I can't recall of the top of my head whether Silverlight supports binding to nested types. You might need to bring your Item class out of ItemsManager and give it a more specific name like ManagedItem.
First, do not bind to BitmapImage unless you have a good reason. Binding to a string is good enough. The implicit conversion will happen automatically. Second, use declaritive binding. Programatic creation and binding is a real mess. Third, only implement INotifyPropertyChanged if you need to send changes of that property to the UI.
You are likely over complicating your situation with all this extra code.
Thanks for explanations. However, I don't need a TwoWay binding. Just one way, once ItemsManager downloads Item image, it should be automatically updated in the Image control.
So, I changed my code to this:
ItemsManager.Instance.AddItem("123");
Binding b = new Binding("BitmapSource");
b.Source = ItemsManager.Instance.GetItem("123");
Image img = new Image();
img.SetBinding(Image.SourceProperty, b);
img.Width = (double)100.0;
img.Height = (double)100.0;
LayoutRoot.Children.Add(img);
I also took Item out of ItemsManager scope, so it is now in its own class file, but image still stays empty, even though bitmap image arrives, and changes in BitmapSource property of Item object.

Resources