Develop Reference

Scrolling problems when using ScaleTransform in Panorama/Pivot/RadSlideView item

I'm trying to implement zoom-functionality in a RadSlideView ItemTemplate. I'm doing this by using a ViewportControl with a Canvas and then applying a RenderTransform (ScaleTransform) to a StackPanel in the Canvas. Similar to the SDK-sample found here.
The problem I have is that the ScaleTransform seems to be affecting the swipe-gesture used to change item in the SlideView/Panorama/Pivot control. E.g. if the ScaleTransform is set to 0.1 it seems like I only need to swipe 1/10th of the length to change item compared to using a ScaleTransform of 1.0.
I found that if I set IsHitTestVisible to false on the ItemTemplate the swiping works like I want. But this is not a solution since I sometimes need to be able to pan the content vertically while still being able to change item by swiping horizontally.
So my question is how can I solve this?
For reference the XAML looks like this:
<Controls:RadSlideView Name="SlideView" ItemsSource="{Binding Pages}" IsLoopingEnabled="False" SelectionChanged="RadSlideView_SelectionChanged" CacheMode="BitmapCache" ManipulationStarted="SlideView_ManipulationStarted" ManipulationCompleted="SlideView_ManipulationCompleted" ManipulationDelta="SlideView_ManipulationDelta">
<Controls:RadSlideView.ItemTemplate>
<DataTemplate>
<ViewportControl x:Name="SlideViewViewport" ViewportChanged="SlideViewViewport_ViewportChanged" Loaded="SlideViewViewport_Loaded">
<Canvas>
<StackPanel>
<Image Source="{Binding Image}" Stretch="Fill" Width="{Binding ElementName=SlideView, Path=DataContext.PageWidth}" Height="{Binding ElementName=SlideView, Path=DataContext.PageHeight}" CacheMode="BitmapCache"/>
<StackPanel.RenderTransform>
<ScaleTransform x:Name="xform"/>
</StackPanel.RenderTransform>
</StackPanel>
</Canvas>
</ViewportControl>
</DataTemplate>
</Controls:RadSlideView.ItemTemplate>
I have also looked at Teleriks RadPanAndZoom-control to avoid implementing my own zoom-functionality, but since I sometimes need to place two pictures side by side and zoom them as if they were one I don't think I can use it.

The problem is that ScaleTransformation scales your picture, but doesn't change it's height and width. Only if Height And Width are overflowing scrollviewer you can scroll the content

How to display SkeletonStream on a DepthStream or ColorStream Kinect Wpf

I would like to know how to overlay two Image objects in Wpf. I've made two streams which output a video, one for bones and another just a normal video. Now I would like to add them together, so the skeleton would be displayed on the color video.
A part of my XAML code is
<Grid Name="layoutGrid">
<Grid Name="VideoGrid" ClipToBounds="True" Background="AliceBlue">
<Image Name="ColorImage" Width="640" Height="480"/>
<Image Name="SkeletalImage" Width="640" Height="480"/>
<Canvas Background="Transparent"/>
</Grid>
<StatusBar VerticalAlignment="Bottom" HorizontalAlignment="Center">
<Button Name="Button1" Content="Skeleton Only" Width="120"/>
</StatusBar>
</Grid>
When I do this, only the Skeletal image is displayed and if I switch the both Images then the color image is shown. It seems like Canvas background doesn't do the trick (to make the black part of skeletal image transparent)

I thought the problem was in my XAML code but it was actually at drawing the transparent background to set the render size. The background for skeleton image was black
dc.DrawRectangle(Brushes.Black, null,
new Rect(0.0, 0.0, RenderWidth, RenderHeight));
instead of transparent
dc.DrawRectangle(Brushes.Transparent, null,
new Rect(0.0, 0.0, RenderWidth, RenderHeight));
that fixed my problem.
Thanks though

I've tried overlaying Skeletal onto color or depth on a canvas, but it never worked out. Instead, when I looked at the Kinect Explorer sample application in the SDK 1.6.0, they overlay using a grid. Unfortunately, I have not learned that much yet, but they used a grid for the color and depth, and a canvas for the skeletal tracking. I can post a snippet if it helps. Good luck!

You are asking basically two different questions: 1) How to display SkeletonStream on a DepthStream, which is very easy, 2) How to display SkeletonStream on a ColorStream, which is still easy but a little more complicated.
Answer to Question 1) The XYZ Vectors of the joints in the skeletal streams are in the same coordinate system as the Depth Stream. So if you plot the Deapth Stream as a quadratic mesh using the focal length of the depth camera from the Kinect SDK, you can plot the skeleton as a line plot in the same coordinate system. The source code that implements exactly what you want to do in OpenGL is available here that will give you an idea how to implement this in wpf.
Answer to Question 2) The video camera has a different field of view from the depth camera. To display the skeleton stream to the ColorStream you need first to map the XYZ vectors of the joints in the skeletal streams to the coordinate system of the depth stream and then draw first the video frame in the background and the skeleton as a line plot on the front.
You can easily do the mapping using the U-V texture coordinates given by the Kinect SDK. See how you can get the UV here.

How do I get a ScrollViewer with a Rectangle inside to stop scrolling when it reaches the end of the rectangle?

I have created a Rectangle inside of a ScrollViewer like this
<ScrollViewer ManipulationMode="Control" x:Name="songScrollViewer" HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Disabled" Height="270" VerticalAlignment="Center" Width="728" Canvas.Top="20" d:LayoutOverrides="HorizontalMargin" >
<Rectangle x:Name="musicBG" Fill="#FF0692FD"/>
</ScrollViewer>
During the use of the app, the size of MusicBg changes, sometimes to something around 3,000 pixels width.
musicBG.Width = _songLength*PixelsPerSecond
However, while scrolling the scrollViewer, it allows me to scroll the rectangle all the way off the screen.
For example this line of code gives me the following values when I have moved the rectangle as far as I want to move it.
if (songScrollViewer.HorizontalOffset > songScrollViewer.ScrollableWidth)
HorizontalOffset has a value of ~1200 and ScrollableWidth has a value of about ~2900.
How can I get this to be done properly so that the rectangle is not scrolled completely off the screen?
I would expect a HorizontalOffset of about 1200 to only push the rectangle about halfway through to it's destination, and not make it start going off screen.
ANSWER:
After much frustration, I was able to solve this problem by using Canvas instead of Border or Rectangle.
I'll award points if anyone can explain why this problem happened, and if there is a less processor intensive control that would work better than canvas.
Edit: Screen shots:
Bad Code:
<ScrollViewer ManipulationMode="Control" x:Name="songScrollViewer" Width="720" HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Disabled" Height="270" VerticalAlignment="Top" Canvas.Top="20" HorizontalAlignment="Left" >
<Border x:Name="musicBG" Background="#FF0692FD" VerticalAlignment="Top" HorizontalAlignment="Left" Height="270" />
</ScrollViewer>
Image of bad scroll with bad code:
Good working code:
<ScrollViewer ManipulationMode="Control" x:Name="songScrollViewer" Width="720" HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Disabled" Height="270" VerticalAlignment="Top" Canvas.Top="20" HorizontalAlignment="Left" >
<Canvas x:Name="musicBG" Background ="#FF0692FD" Height="270" >
<Border Background="#FF0692FD" VerticalAlignment="Top" HorizontalAlignment="Left" Height="270" />
</Canvas>
</ScrollViewer>
Good Scroll: Notice it says 170 seconds on the bottom right instead of the smaller number of 118 seconds in the bad scroll.

I believe your right, wp7 won't render shapes that are bigger then 2048 pixels. So the reason it's scrolling of the page is because it's treating it as if it were bigger then 2048 but you can only see up to a width of 2048px and its just scrolling over to the "ghost" part of the rectangle.
I'm not sure if you can override this but the best solution I could come up with (without overriding) is by splitting up your rectangle into chucks that are smaller then 2000 (just to be safe) and then displaying them seamlessly in a horizontal stack panel inside the scroll viewer. The problem with this is that depending on how you've coded it, this solution might be hard to implement; but you might just be able to split it in your ViewModel when displaying it and your logic would only see it as one big chunk.

Image in WPF getting Blurry

I am developing an application in WPF using C#. I am putting Images in a WrapPanel and showing inside a Grid with one more Border and using images in Buttons also. Problem is my Image control loosing its quality. I am not able to post my image here so I am simply describing here.
I used SnapsToDevicePixels="True" for the images but still it looks blurry.
Updated:
Here I shared the Image below:

I think what Markus told is the one way to resolve your issue and try by adding one more property in it RenderOptions.EdgeMode="Aliased" for each image I mean :
<Image Source="/LoginPanel;component/Icons/icoLogin.ico"
RenderOptions.BitmapScalingMode="NearestNeighbor"
RenderOptions.EdgeMode="Aliased"/>
if you still not able to fix your problem then you can refer this http://blogs.msdn.com/b/dwayneneed/archive/2007/10/05/blurry-bitmaps.aspx to create a custom Bitmap class and apply on all Images which are creating trouble for you.
You can also see this Stack Overflow Question

SnapsToDevicePixels seems not working for bitmaps.
The NearestNeighbor options actually converts the bitmap and will end up with different one to the original bitmap.
In WPF 4, a property "UseLayoutRounding" on the FrameworkElement is introduced to solve this problem.
By setting this property to True on your root element, such as Window will align children elements on the edges of pixels.
<Window UseLayoutRounding="True">...</Window>

This works for me
<Image Source="/LoginPanel;component/Icons/icoLogin.ico"
RenderOptions.BitmapScalingMode="NearestNeighbor"</Image>
Set RenderOptions.BitmapScalingMode="NearestNeighbor" for each image. Alternatively see this question here on StackOverflow.
Edit:
Here is my sample code
<Window x:Class="MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="661">
<WrapPanel>
<Button VerticalAlignment="Center">
<Image Source="/WpfApplication1;component/icoChip32x32.ico"
RenderOptions.BitmapScalingMode="NearestNeighbor" Stretch="None"></Image>
</Button>
<Button VerticalAlignment="Center">
<Image Source="/WpfApplication1;component/icoChip32x32.ico"
RenderOptions.BitmapScalingMode="NearestNeighbor" Stretch="None"></Image>
</Button>
<Button VerticalAlignment="Center">
<Image Source="/WpfApplication1;component/Presentation-Edit.png"
RenderOptions.BitmapScalingMode="NearestNeighbor" Stretch="None"></Image>
</Button>
<Button VerticalAlignment="Center">
<Image Source="/WpfApplication1;component/Presentation-Edit.png"
RenderOptions.BitmapScalingMode="NearestNeighbor" Stretch="None"></Image>
</Button>
</WrapPanel>
</Window>
And this is my result:

Use UseLayoutRounding="True" property on the parent element if image is used as a content. In your case it is the Button.

I ran into a blurriness issue with image backgrounds caused by scaling and the solution was much simpler than you may think. While at first I wondered if it was being scaled up to a power-of-two texture size, the scaling actually matched the ratio of System DPI (96) : Image DPI (72, which is the default for many editors). If you adjust the image to 96 DPI it should display pixel-perfect with the default Windows settings.
EDIT: Tried an image with high detail contrast and it is slightly softened.

WPF doesn't use concrete pixel values for sizes and positioning, so that it can scale well with DPI.
This can lead to a problem where it tries to use a position that doesn't correspond to a discrete on-screen pixel; some of the image pixels are rendered over multiple on-screen pixels which we see as blurring.
UseLayoutRendering=true with SnapToDevicePixels=false should solve this issue. You also need to set it at the main window level too, so that the calculations cascade down to the image level.
You can try this out by creating a simple WPF application with one window, and your images. Setting the image margin to be something silly like (10.452, 0.736, 0, 0) will lead to blurring. This goes away with UseLayoutRendering=true on the image.
If you then set the margin again in your window's constructor after InitializeComponent(), it is blurry regardless of whether you set UseLayoutRendering=true on the image, since the calculations to line up with on-screen pixels were made before you then moved the image to a location which doesn't match up with these.
I'm not entirely sure what the difference is between UseLayoutRendering and SnapToDevicePixels - I think it is just the time that the calculations are made. UseLayoutRendering seems to be preferable for images.
Stretching/squashing an image from its original size can also lead to blurring problems.

I had the same Problem, but in my case I've downloaded Icons and found out, that they all had wrong DPI too... 110,56 and 116,xx and 95,99 etc...
When i changed the DPI to 96 for all, everything was fine!

Coordinate system problem with the grid control

In my WPF application im trying to visualize some temperature data. I have a list of temperatures for the 7 past days and want to make a point to point line diagram. My problem is with the different koordinatesystems and adjusting data to the grid.
XAML:
<Grid Height="167" HorizontalAlignment="Left" Margin="6,6,0,0" Name="grid1" VerticalAlignment="Bottom" Width="455" />
C# (draft):
http://pastebin.com/6UWkMFj1
scale is a global variable that changes with a slider (1-10). How to i correct my application so the line always is centered? As it is now it starts out centeded but if i crank up the slider to 3-4 the line goes up and above the applicationwindow. I also would like to use the full height of the grid window not just a small piece like images below:
http://img32.imageshack.us/i/002wtvu.jpg/
http://img691.imageshack.us/i/001tqco.jpg/
As you can see i have worked out my data so day 1 with temperature 62 F is lower then day 2 with temperature of 76 F but i have scaling issues and placementissues... could somebody straighten out my math? :-)

I don't think that drawing on a grid is a good idea... Canvas should do... give it a try. Here is a link with related stuff that might be helpful.