making animation of fading picture - c#

I need to do a simple game , which the player should tap the pictures in a time limit
and when the player taps the picture , i want to make animation of the picture fading out
I am using Visual Studio 2012 Express for Windows Phone
I think it's has something to do with OpacityProperty
Am not asking for the whole code to do it , i only want a helpful way to start

Just create a Storyboard animation changing the Opacity of the image, something like
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="ImageName"
Storyboard.TargetProperty="Opacity"
From="1.0" To="0.0" Duration="0:0:1"
/>
</Storyboard>

Related

WPF C#: Prevent Storyboard animation from starting if Panel.Width is already greater than 0

Is there a way to prevent the animation from starting if the width is greater than 0. The problem is that when the width is already 250 if the animation starts, it will reset the panel width to 0 then will start the animation.
<Storyboard x:Key="Expand">
<DoubleAnimation From="0" To="250" Duration="00:00:01" Storyboard.TargetProperty="(DockPanel.Width)" Storyboard.Target="{Binding ElementName=Panel}"/>
</Storyboard>

How to set dynamic DoubleAnimation To or From values

I have a number of scenarios where I am doing simple WPF storyboard animations as such.
<Storyboard x:Key="MyTextBlockStoryBoard" RepeatBehavior="Forever">
<DoubleAnimation AutoReverse="True"
Duration="0:0:8"
From="0.0"
Storyboard.TargetName="MyTextBlock"
Storyboard.TargetProperty="(Canvas.Left)"
To="500.0" />
</Storyboard>
However I need to be able to set the To value in this animation to a dynamic value which is equivalent to UserControl.ActualWidth - MyTextBlock.ActualWidth. I understand that obviously I can easily create a Storyboard as above programmatically but I am hoping to stay inside Xaml world.
My inkling is that the only way I can achieve this is through implementing my own IValueConverter but I am hoping that there might be a easier way to achieve my desired output?

Pixel Shader Effect in WPF

I was following along this tutorial about how to include Pixel Shader Effects in the form of an animation within a WPF application.
Background
I felt like things were going smoothly, however I wanted to make a change to the application. In the tutorial the author has a separate GrayscaleEffect project and in his XAML does the following:
xmlns:effect="clr-namespace:GrayscaleEffect;assembly=GrayscaleEffect"
Later he has this:
DataTemplate x:Key="itemTemplate">
<Grid Width="225" Margin="3">
<Border BorderBrush="White" BorderThickness="2">
<Image Source="{Binding}" HorizontalAlignment="Center" VerticalAlignment="Center">
<Image.Effect>
<local:GrayscaleEffectTest x:Name="grayscaleEffect"/>
</Image.Effect>
<Image.Triggers>
<EventTrigger RoutedEvent="Mouse.MouseEnter">
<BeginStoryboard>
<Storyboard>
<!--HERE--> <DoubleAnimation To="1.0" Duration="0:0:0.3" AccelerationRatio="0.10" DecelerationRatio="0.25" Storyboard.TargetName="grayscaleEffect" Storyboard.TargetProperty="(local:GrayscaleEffectTest.DesaturationFactor)" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
<EventTrigger RoutedEvent="Mouse.MouseLeave">
<BeginStoryboard>
<Storyboard>
<DoubleAnimation To="0.0" Duration="0:0:4" AccelerationRatio="0.10" DecelerationRatio="0.25" Storyboard.TargetName="grayscaleEffect" Storyboard.TargetProperty="(local:GrayscaleEffectTest.DesaturationFactor)" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Image.Triggers>
</Image>
</Border>
</Grid>
</DataTemplate>
The key point here is the very long line <DoubleAnimation ....:
Storyboard.TargetProperty="(effect:GrayscaleEffect.DesaturationFactor)" />
My Approach
I wanted to make the same thing, except I wanted to keep all of my code in the same project, rather than having two projects.
So, I don't include the ;assembly=GrayscaleEffect. Furthermore my <DoubleAnimation ... line reads as:
<DoubleAnimation ... Storyboard.TargetName="grayscaleEffect" Storyboard.TargetProperty="(local:GrayscaleEffectTest.DesaturationFactor)" />
However the WPF designer throws an initializer exception. The program runs but no animation ever gets triggered when I mouse over...
Anyone have any ideas? I feel confident that WPF should be able to run a pixel shader from within the same project...My project has the pre-build event, and other than renaming as GrayscaleEffect Test and having both projects combined into one, my project should be identical to the tutorial. I've tried a number of other failure approaches, mainly setting Storyboard.TargetProeprty = every damn thing under the sun. Also tried to hack together something to set up the animation in code behind in hopes I could at least walk through with a debugger and try to see what is going on. Obviously, nothing worked :(.
Any help would be greatly appreciated. Cheers.
Slightly embarrassing but the error was between chair and keyboard. So, the code was working just fine. To maybe help others I'll explain my debugging process, then explain what the problem was.
First I changed the pixel shader to just go from Red to Red and Green. That is:
result.r = 255;
result.g = 0;
result.b = 255 * factor;
Factor is the data variable that gets sent to the graphics card. Once I did this, I noticed that things were kind of working. The transition is a step-function, not a linear interpolation, but colors were changing. Then, I figured pixel color range must be [0 to 1.0]. This gave me the effect I was supposed to be getting.
result.r = 1.0;
result.g = 0;
result.b = 1.0 * factor;
Lastly, I loaded a new penguin picture instead of the original test image I was using and I realized my major mistake. The penguin picture was working just fine and I thought, what the hell?! Then I looked at my test image, which was a black and white image!!! (Dumb, dumb dumb dumb). The shame of having to post this "solution" will hopefully prevent me from making such a mistake again. Thank you for the help #Nico Schertler.

How can I trigger animation from C#? [duplicate]

This question already has an answer here:
Closed 10 years ago.
Possible Duplicate:
Start Storyboard When Text Changes
I've created a animation:
<phone:PhoneApplicationPage
...>
<phone:PhoneApplicationPage.Resources>
<Storyboard x:Name="MessageFadeInOut" Storyboard.TargetProperty="Opacity">
<DoubleAnimation From="0" To="1" Duration="0:0:1" BeginTime="0:0:0" />
<DoubleAnimation From="1" To="1" Duration="0:0:1" BeginTime="0:0:1" />
<DoubleAnimation From="1" To="0" Duration="0:0:1" BeginTime="0:0:2" />
</Storyboard>
</phone:PhoneApplicationPage.Resources>
What I'm trying to do where is have something fade in, stay for a bit then fade out.
I trigger it by:
private void Unit_Tap_1(object sender, System.Windows.Input.GestureEventArgs e)
{
Storyboard sb = this.Resources["MessageFadeInOut"] as Storyboard;
Storyboard.SetTarget(sb, this.Message);
sb.Begin();
}
But on the sb.Begin() I get "System.InvalidOperationException". How come? Message is a Image
I'm not sure what "Message" is in this context, and that might be the reason why you're seeing this exception. Or it might not be .
Either way, you shouldn't grab Storyboards and start those manually. You should use VisualStateManager to manage your visual states by encapsulating a storyboard in each state. You can read more about this # Start Storyboard When Text Changes
A good way to get started in VSM would be to watch these videos by Steve White in the Expression Blend 2 launch:
Adding Control States # http://msdn.microsoft.com/en-us/expression/ff898424
Create Custom Buttons # http://msdn.microsoft.com/en-us/expression/ff921363
Customize a Checkbox’s Checkmark # http://msdn.microsoft.com/en-us/expression/ff921365
Use an In-State Animation # http://msdn.microsoft.com/en-us/expression/ff921380
Each of these videos is part of a series, so consider watching the rest of the series. There are also articles you can read # http://www.interact-sw.co.uk/iangblog/2008/06/10/visual-state

WPF, Opacity and Threads

I have two overlapping (in same position, having the same size) MediaElements. They will contain images. The opacity of one element will be set to 1.0 and the opacity of the other set to 0.0. The idea here would be a simple transition for a slide-show type deal. When it's time to display the next slide, the background element loads a picture and the opacity of both elements switches gradually.
I tried (successfully) to implement this behavior using System.Timers, only to find that having more than some arbitrary number of timers in the same application would cause .NET to randomly spawn and cede control of timer_elapsed to several different threads. This caused unpredictable results and generally made me question my sanity.
So, I decided to do the same thing, but with System.Threads and their Sleep functions. For whatever reason, gradually cycling the opacity worked perfectly with the insane timers but fails utterly with threads. And it fails in a ridiculous way. The opacity of both elements does change, but there's no in between. The element is shown either with opacity at 1.0 or 0.0. Otherwise I would notice that roughly half the pictures weren't being cycled through.
After much googling, I thought perhaps the priority of the thread that the opacity changes were occurring on was somehow keeping the UI elements from being rendered immediately. But then I recalled that because I was using dispatcher invocations on the media elements, all of the action was taking place on the main thread anyway, so it wouldn't make a difference.
Contemplate the following code: https://gist.github.com/956093
As suggested you should use the native animations; i have come accross this thread issue before as well and in general i try to avoid using Dispatchers, i pretty much only use them to modify data if i must (e.g. ObservableCollection cannot be modified in a background thread, don't know any other examples actually).
You could still use normal threads, they work well if you use bindings to update the UIElements which nicely bypasses the dispatching issue.
Animation example:
<Grid Name="testGrid" Tag="2">
<Grid.Resources>
<Storyboard x:Key="FadeAnim2to1">
<DoubleAnimation Storyboard.Target="{x:Reference img1}"
Storyboard.TargetProperty="Opacity"
Duration="0:0:1" To="1"/>
<DoubleAnimation Storyboard.Target="{x:Reference img2}"
Storyboard.TargetProperty="Opacity"
Duration="0:0:1" To="0"/>
</Storyboard>
<Storyboard x:Key="FadeAnim1to2">
<DoubleAnimation Storyboard.Target="{x:Reference img1}"
Storyboard.TargetProperty="Opacity"
Duration="0:0:1" To="0"/>
<DoubleAnimation Storyboard.Target="{x:Reference img2}"
Storyboard.TargetProperty="Opacity"
Duration="0:0:1" To="1"/>
</Storyboard>
</Grid.Resources>
<Image x:Name="img1" Source="Images/Default.ico" Width="200" Height="200" Opacity="0"/>
<Image x:Name="img2" Source="Images/Error.ico" Width="200" Height="200"/>
</Grid>
<Button Content="Fade" Click="Button1_Click"/>
private void Button1_Click(object sender, RoutedEventArgs e)
{
Storyboard anim;
if ((string)testGrid.Tag == "1") //This is just for brevity, you should of course not use the Tag to store state information, let alone number strings
{
anim = testGrid.Resources["FadeAnim1to2"] as Storyboard;
testGrid.Tag = "2";
}
else
{
anim = testGrid.Resources["FadeAnim2to1"] as Storyboard;
testGrid.Tag = "1";
}
anim.Begin();
}

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