I was added picture as a children to layer called "canvas". By the following code:
if (addChild)
{
Image i = new Image();
BitmapImage src = new BitmapImage();
src.BeginInit();
src.UriSource = new Uri(path, UriKind.Absolute);
src.EndInit();
i.Source = src;
i.Width = 200;
i.IsManipulationEnabled = true;
double rotAngle = Rand.GetRandomDouble(-3.14/4, 3.14/4);
i.RenderTransform = new MatrixTransform(Math.Cos(rotAngle), -Math.Sin(rotAngle),
Math.Sin(rotAngle), Math.Cos(rotAngle), Rand.GetRandomDouble(0, this.Width - i.Width), Rand.GetRandomDouble(0, this.Height - i.Width));
canvasImages.Add(i);
canvas.Children.Add(i);
Canvas.SetZIndex(i, canvas.Children.Count-1);
addedFiles.Add(path);
maxZ++;
}
Here is the problem. I'm trying to make an event called "canvas_TouchDown" which can detect the specify picture when I touched it so that it will get the center of that image object.
List<Image> canvasImages = new List<Image>();
private void canvas_TouchDown(object sender, TouchEventArgs e)
{
foreach (Image canvasImage in canvasImages)
{
if (canvasImage.AreAnyTouchesCaptured == true)
{
System.Diagnostics.Debug.WriteLine("I found image that you touch");
}
}
}
However, there is nothing happened. I also try to use PersistId property but it doesn't work. Have any suggestion?
Regard,
C.Porawat
If you are adding the image to the canvas, touching it and expecting the canvas to receive the touch you will be disappointed. You should either listen to "touch down" on the image or "preview touch down" on the canvas.
Related
I created a simple example to test the image control's memory handling.
On a dockpanel there are two buttons ("Load" and "Reset") and an image control.
In the code behind, the event handlers of the buttons look like this:
private void LoadButton_Click(object sender, RoutedEventArgs e)
{
var dlg = new OpenFileDialog
{
Title = "Open image file",
DefaultExt = ".tif",
Filter = "",
Multiselect = false,
InitialDirectory = "D:\\testimages"
};
dlg.ShowDialog();
string file = dlg.FileName;
if (!string.IsNullOrEmpty(file))
{
if (this.img.Source != null)
{
this.img.Source = null;
this.img.UpdateLayout();
GC.Collect();
}
var bi = new BitmapImage();
bi.BeginInit();
bi.CacheOption = BitmapCacheOption.OnLoad;
bi.UriSource = new Uri(file);
bi.EndInit();
bi.Freeze();
this.img.Source = bi;
}
else
{
this.img.Source = null;
this.img.UpdateLayout();
GC.Collect();
}
}
private void ResetButton_Click(object sender, RoutedEventArgs e)
{
this.img.Source = null;
this.img.UpdateLayout();
GC.Collect();
}
When I load the first image, the memory usage increases. Hitting the Reset-button, the memory is released correctly. So far this looks like correct behaviour.
But if I do not "reset", but load another image, the memory usage increases.
"Reset" does only release the memory of the latest image.
How can I make sure, that the memory of previously loaded images gets released when loading the next image?
The images I use are app. 4000 x 1000 px with a resolution of 300dpi.
How can i implement FadeIn and then FadeOut image when i change image source like slide show. my images load from local and web and count of that is varaible.
Thankyou
You could write an extension method that fades out the image by animating its Opacity property to 0, then sets the Source property and finally animates the opacity back to 1.
public static void ChangeSource(
this Image image, ImageSource source, TimeSpan fadeOutTime, TimeSpan fadeInTime)
{
var fadeInAnimation = new DoubleAnimation(1d, fadeInTime);
if (image.Source != null)
{
var fadeOutAnimation = new DoubleAnimation(0d, fadeOutTime);
fadeOutAnimation.Completed += (o, e) =>
{
image.Source = source;
image.BeginAnimation(Image.OpacityProperty, fadeInAnimation);
};
image.BeginAnimation(Image.OpacityProperty, fadeOutAnimation);
}
else
{
image.Opacity = 0d;
image.Source = source;
image.BeginAnimation(Image.OpacityProperty, fadeInAnimation);
}
}
You can use WPF transition for this, please check at Here
My application loads a lot of images in a BackgroundWorker to stay usable. My Image control is bound to a property named "ImageSource". If this is null it's loaded in the background and raised again.
public ImageSource ImageSource
{
get
{
if (imageSource != null)
{
return imageSource;
}
if (!backgroundImageLoadWorker.IsBusy)
{
backgroundImageLoadWorker.DoWork += new DoWorkEventHandler(bw_DoWork);
backgroundImageLoadWorker.RunWorkerCompleted +=
new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
backgroundImageLoadWorker.RunWorkerAsync();
}
return imageSource;
}
}
void bw_DoWork(object sender, DoWorkEventArgs e)
{
bitmap = new BitmapImage();
bitmap.BeginInit();
try
{
bitmap.CreateOptions = BitmapCreateOptions.DelayCreation;
bitmap.DecodePixelWidth = 300;
MemoryStream memoryStream = new MemoryStream();
byte[] fileContent = File.ReadAllBytes(imagePath);
memoryStream.Write(fileContent, 0, fileContent.Length);
memoryStream.Position = 0;
bitmap.StreamSource = memoryStream;
}
finally
{
bitmap.EndInit();
}
bitmap.Freeze();
e.Result = bitmap;
}
void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
BitmapSource bitmap = e.Result as BitmapSource;
if (bitmap != null)
{
Dispatcher.CurrentDispatcher.BeginInvoke(
(ThreadStart)delegate()
{
imageSource = bitmap;
RaisePropertyChanged("ImageSource");
}, DispatcherPriority.Normal);
}
}
This is all well so far but my users can change the images in question. They choose a new image in an OpenDialog, the old image file is overwritten with the new and ImageSource is raised again which loads the new image with the same filename again:
public string ImagePath
{
get { return imagePath; }
set
{
imagePath= value;
imageSource = null;
RaisePropertyChanged("ImageSource");
}
}
On some systems the overwriting of the old file results in an exception:
"a generic error occured in GDI+" and "The process cannot access the file..."
I tried a lot of things like loading with BitmapCreateOptions.IgnoreImageCache and BitmapCacheOption.OnLoad. This raised Exceptions when loading them:
Key cannot be null.
Parameter name: key
If I try this without the BackgroundWorker on the UI thread it works fine. Am I doing something wrong? Isn't it possible to load the images in the background while keeping the files unlocked?
Well, it seems all of the above works. I simplified the example for the question and somehow on the way lost the problem.
The only difference I could see in my code is that the loading of the image itself was delegated to a specific image loader class which somehow created the problem. When I removed this dependency the errors disappeared.
This is kind of a weird problem I am having right now. What I am trying to do is animate a Run element to essentially flash/blink. The parent is a Hyperlink which contains multiple Inlines of type Run and Image. Now I am trying to animate the Foreground color of the element but it does not seem to work.
Here is my code for a hyperlink.
CallbackHyperLink callbackLink = new CallbackHyperLink();
ToolTipService.SetShowDuration(callbackLink, 3600000);
ToolTipService.SetInitialShowDelay(callbackLink, 0);
callbackLink.Foreground = new SolidColorBrush(Colors.Magenta); // Default text color of the link
callbackLink.TextDecorations = null; // Disable the underline until mouse over
callbackLink.ToolTip = f.Tooltip; // Set the tooltip string
DoubleAnimation opacityAnim = new DoubleAnimation();
opacityAnim.From = 1.0;
opacityAnim.To = 0.0;
opacityAnim.FillBehavior = FillBehavior.Stop;
opacityAnim.Duration = TimeSpan.FromSeconds(BlinkDurationOff);
opacityAnim.AutoReverse = true;
_blinkAnimation.Children.Add(opacityAnim);
Storyboard.SetTarget(opacityAnim, callbackLink.Foreground);
Storyboard.SetTargetProperty(opacityAnim, new PropertyPath(SolidColorBrush.OpacityProperty));
_blinkAnimation.Stop();
_blinkAnimation.Begin();
So that gets put in a storyboard which get fired. However the foreground is not getting animated and I am not seeing any warnings that im trying to animate something I shouldn't. Anybody have any ideas?
Thanks
This works:
Storyboard.SetTarget(opacityAnim, callbackLink);
Storyboard.SetTargetProperty(opacityAnim, new PropertyPath(UIElement.OpacityProperty));
Edit full working example with a TextBlock stolen from here :
void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
TextBlock callbackLink = new TextBlock();
callbackLink.HorizontalAlignment = HorizontalAlignment.Center;
callbackLink.VerticalAlignment = VerticalAlignment.Center;
callbackLink.Text = "Test";
this.Content = callbackLink;
NameScope.SetNameScope(this, new NameScope());
var b = new SolidColorBrush(Colors.Magenta);
callbackLink.Foreground = b;
this.RegisterName("MyAnimatedBrush", b);
DoubleAnimation opacityAnimation = new DoubleAnimation();
opacityAnimation.To = 0.0;
opacityAnimation.Duration = TimeSpan.FromSeconds(0.5);
opacityAnimation.AutoReverse = true;
opacityAnimation.RepeatBehavior = RepeatBehavior.Forever;
Storyboard.SetTargetName(opacityAnimation, "MyAnimatedBrush");
Storyboard.SetTargetProperty(
opacityAnimation, new PropertyPath(SolidColorBrush.OpacityProperty));
Storyboard mouseLeftButtonDownStoryboard = new Storyboard();
mouseLeftButtonDownStoryboard.Children.Add(opacityAnimation);
callbackLink.MouseEnter += delegate(object sender2, MouseEventArgs ee)
{
mouseLeftButtonDownStoryboard.Begin(this, true);
};
callbackLink.MouseLeave += delegate(object sender2, MouseEventArgs ee)
{
mouseLeftButtonDownStoryboard.Stop(this);
};
}
Also another way to link to the foreground opacity call without registering the name of the brush is the following.
Storyboard.SetTarget(opacityAnim, callbackLink);
Storyboard.SetTargetProperty(opacityAnim, new PropertyPath("Foreground.Opacity"));
This seems to finally work for me. Still tweaking my solution as I am doing a lot of Stop/Begin calls on the animation which I believe is not good way of doing things.
I have an control with a mouse down event where Id like to chnage the Image when the image is clicked. But I cant seem to alter ANY of the images properties in the event.
Event
private void Image_MouseDown(object sender, MouseButtonEventArgs e)
{
BitmapImage bitImg = new BitmapImage();
bitImg.BeginInit();
bitImg.UriSource = new Uri("./Resource/Images/Bar1.png", UriKind.Relative);
bitImg.EndInit();
((Image)sender).Source = null;
((Image)sender).Width = 100;
((Image)sender).Visibility = Visibility.Hidden;
}
The event does fire, and even the .Visibility property does not alter the image and make it hidden.
What am I doing wrong?
Assuming the file is in your application, you need to use the Pack URI scheme:
var img = sender as Image;
BitmapImage bmp = new BitmapImage(new Uri("pack://application:,,,/Resources/Images/Bar1.png"));
img.Source = bmp;
In the above example, this would indicate a subfolder in your project of Resources/Images.