SIlverlight: Can't find Image on Canvas - silverlight

In my Canvas, I have an image object. I haven't set a source in it, but it has coordinates and a size. The tag is:
<Image Canvas.Top="50" Canvas.Left="20" Height="68" Width="110" HorizontalAlignment="Left" Name="image1" Stretch="Fill" VerticalAlignment="Top" />
Here's the problem: When I move the mouse over it, I want to find it. With this code:
VisualTreeHelper.FindElementsInHostCoordinates(point, Application.Current.RootVisual)
It won't find the image unless a source is set. If no source is set, then the image isn't returned. Does anyone know why? This is causing me problems. I have some drag/drop code and I'm looking to drop something on that Image control, but I need to know when the mouse is over it.
I know there are other ways I could do it (such as placing something else in that location, like a grid or something and detecting that), but that's not going to work. I can think of several ways that will work, but they're far less elegant.
If I could get the above to return my image, that would definitely be ideal.

In your code you had Point point = e.GetPosition(_canvas); This gets the MousePosition co-ordinates in relation to the canvas, but your second line VisualHelper.FindElementsInHostCoordinates(point,Application.Current.RootVisual) is searching in relation to the whole page. You need to change one or the other so they in relation to the same control. I would just change to VisualHelper.FindElementsInHostCoordinates(point,_canvas)

You can add a <Border> object around the Image object.
Or you can add eventhandlers for the mouseenter and mouse leave and change the Cursor.

Related

Trying to wrap and scale text in a textblock WPF

I'm trying to auto scale the font and wrap text in a TextBlock in WPF and I can't figure it out.
I've Googled it and looked at stackoverflow loads of times and the main suggestion is to place a TextBlock inside a ViewBox. I've tried that, and all it does is scale the whole text down to one line instead of wrapping it.
If I just use a TextBlock without a ViewBox it wraps, but doesn't scale to fit. It's driving me mad, as I am literally trying to move from WinForms to WPF to make better looking UIs.
I've tried StackPanel and DockPanel and they still don't have the desired effect.
All I want is a TextBlock to take a string of text of unknown size and display it scaled and wrapped. I don't understand why it's so difficult
It is helpful to include code of what you have tried.
When I do this:
<Grid>
<TextBox VerticalAlignment="Center" TextWrapping="Wrap" Width="100"/>
</Grid>
I get this:
Is that what you are looking for?
You could also check out the RichTextBox if you need more features.

WPF control origin point

After some investigation, I still can't find method to change origin of control.
So, I want just to place one square exactly in center of another square, without margins, so it will be completely independent of first square size.
Theoretically, it can be easily done with HorizontalAlignment and VerticalAlignment set to Center, since it automatically sets Margin of control to half of width and height of parent control. But it is not so simple.
Simplest way to describe problem is next picture
As you can see, margin is counted towards upper left corner. Which is what I call origin. The perfect solution is to change it to center of first square, but this is where I need help - how can I do that?
Point of origin applies when using a transform object, and attaching the transform to your control. It won't actually effect the behaviour of the margin or left, top properties. If using a transform to place your object, point of origin is very useful.
The top, left (if using cavas) and margin (if using say grid) help govern the "auto" placement by the parent control, and this in turn governs where point of origin for the control winds up being relative to the parent control. The transform object then offsets RELATIVE to where that point of origin is.
The other useful thing is that transform overrides the auto placement in the parent control, or rather, forces an offset to where the parent wants to put it, which in some cases is useful - i.e., you might have boxes listed in a grid and want them to "shake" left and right when you hover the mouse over them, their alignment stays in order to the grid, but the transform lets you bump them away from their "forced" position.
For example, attach the same transform object to 2 controls, and set their origins separate, then apply an animation to the transform object - both controls will animate off the one animation object (if you wanted to their movement in perfect sync).
Well, it was weird enough. The given behaviour can be seen only when using Image, and Center alignment. Can be solved by either wrapping Image in Grid, which will be using Center alignment, or using Stretch alignment with Image (which is much simplier).
<Grid Width="500" Height="500">
<Image Width="250" Height="250" VerticalAlignment="Stretch" HorizontalAlignment="Stretch"/>
</Grid>
If you want to reproduce problem I've described in question, replace Stretch with Center in code above.
Probably oversimplifying here but I would just use a Grid to wrap the two items you mentioned like this example (One stretched to fit and one centered):
<Grid>
<Border HorizontalAlignment="Stretch" VerticalAlignment="Stretch" BorderBrush="Black" BorderThickness="10" Margin="4"/>
<Button HorizontalAlignment="Center" VerticalAlignment="Center" Padding="10">InnerButton</Button>
</Grid>

WPF: how to write text in a different direction?

I need to write text in the orientation specified for the image below. The fact is that I saw some examples around here by using a textblock and rotating the angle of the control using "RenderTransform", but this is not what I really need. I tried to do it using an image but it doesn't fit very well... so I really don't know how to solve it. If you look at the image beside you can see that the text is written from bottom to top and the line below the text is in the right of the screen.
This is the screen that I need to develop:
I tried by rotating the textblock, but the only way that it works for me was wrapping the text, but this is just the "closest" solution that I found. Also, as you can see, I need to set a border for the textblock.
Anyway, I hope you can help me because any example around fits with my problem.
In order to rotate your text at 90 degrees, I believe that you will need to use the LayoutTransform instead of the RenderTransform:
<TextBlock Text="FootRoller" HorizontalAlignment="Center" VerticalAlignment="Center">
<TextBlock.LayoutTransform>
<RotateTransform Angle="-90"/>
</TextBlock.LayoutTransform>
</TextBlock>
The difference is when the transform will be applied. Using the LayoutTransform, the text will be rotated before the layout pass and this will be important in your case. I imagine that using the RenderTransform will rotate your TextBlock, but as it does that after the layout pass, it would not show it all... this is because it was measured for size before it was rotated.
You can find out full details from the Transforms Overview page on MSDN. From the linked page:
LayoutTransform – A transform that is applied before the layout pass. After the transform is applied, the layout system processes the transformed size and position of the element.
RenderTransform – A transform that modifies the appearance of the element but is applied after the layout pass is complete. By using the RenderTransform property instead of the LayoutTransform property, you can obtain performance benefits.
They're all right. RenderTransform should be all you need. Like;
<TextBlock Text="FootRoller" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Center" VerticalAlignment="Center">
<TextBlock.RenderTransform>
<CompositeTransform Rotation="-90"/>
</TextBlock.RenderTransform>
</TextBlock>
P.S. - You can literally just change RenderTransform to LayoutTransform which Sheridan has provided an explanation for in his answer.
If RenderTransform didn't work, take a look at LayoutTransform. You didn't tell us why RenderTransform didn't work but it's usually a safe bet that LayoutTransform will solve whatever problem it gave you.

How to mix text-only RibbonToggleButton and image-only RibbonButton in Ribbon for WPF?

I'm using the Microsoft Ribbon for WPF October 2010 and have got 3 buttons next to each other, inside a RibbonControlGroup. The left and the right ones are text-only RibbonToggleButton controls, the one in the middle is an image-only RibbonButton. The buttons have a defined width to match the row above.
My code:
<r:RibbonControlGroup>
<r:RibbonToggleButton Width="110" Label="Outgoing" IsChecked="True" />
<!-- Padding and Height set to align the buttons/image -->
<r:RibbonButton Width="30" Padding="5 0" Height="24" SmallImageSource="Images\Small\arrow_swap.png" />
<r:RibbonToggleButton Width="110" Label="Incoming" />
</r:RibbonControlGroup>
The problem is that as soon as I apply the SmallImageSource to the middle button, the other two get spacings for images, causing the text not to be centered anymore. That is problem (1).
Because I didn't find a quick solution, I tried to add the image of the middle button not via SmallImageSource, but by adding it as <Image> for the content of the button. However, the button would remain empty. That is problem (2).
My third solution was to add images to the left and the right button, too. Unfortunately there is nearly no margin between the image and text, which looks quite ugly. I tried several things to enlarge the margin like adding a <Style TargetType="Image"> to the <RibbonToggleButton.Resources>, but although the editor accepts it and displays the spacing at designtime, the margin is gone again at runtime. That is problem (3).
Does anybody have an appropiate solution to any of the three problems? I cannot get it to work. The number of the problems is also the preference of the alternatives, (1) being the most favourite to use with an appropiate hack.
It seems you cannot do that. Its by design.
As per MSDN (here about half way down the page):
Related ribbon controls can be grouped together in a RibbonControlGroup. When a control group is resized, one RibbonControlSizeDefinition is applied to all of the controls in the RibbonControlGroup. The RibbonControlGroup is positioned in the RibbonGroup as if it were one control.
All the controls in a RibbonControlGroup shares the same RibbonControlSizeDefinition. Hence, in your case image will be added for all the buttons.
You may use RibbonGroup instead if you do not want to glue all your controls very closely. This way you can customize each button container by using different RibbonControlSizeDefinitions.

Set Pointer to Hand when hovering over UI element in Silverlight

I have an Image, which is attached to some JavaScript on MouseEnter.
This all works fine. When user "Mouses Over", JS is called and storyboard runs as expected.
I also want to change the mouse cursor to a "Hand Pointer" when the user hovers over, probably I guess, this occurs in the same JS function.
Also, how do I change it back?
Many thanks
Answering my own question again:
Turns out there is a Hand attribute I missed.
<Image Canvas.Left="719.732" x:Name="img17_18" Width="180" Height="208.09" Source="Padmamand1.jpg" Stretch="Fill" Canvas.Top="36.91" Opacity="0.595" Cursor="Hand"/>
Sweet.

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