I have an Image control with Stretch==Uniform which means larger images will be scaled down. In my case the Image control fills the whole client space, the scaled down image is being displayed centered inside the control. What now will happen: the size of the rendered image and the Image control do not have the same size - the Image control is usually larger than its content (since I use uniform stretching).
I now need to know the position of the actual image inside the Image control. Some background: the user can place a rectangle on the image to crop it. To match the rectangle with the image coordinates I need to know exactly where the image is.
Is there a way to determine the position of the rendered image inside the Image control? Or is the only solution to make the control the same size as the image content?
To get more control, you might want to put the image on a canvas inside a viewbox.
That way you get pixel control via the canvas, but a scaled view via the outer viewbox. Set the canvas dimensions to match the image and add any decorations to the canvas.
You may need to inverse-scale the rectangle stroke width so that it is visible when the canvas is small.
Related
I am having one canvas. I have added one text box to it using canvas.left and canvas.right property.And already there is a image inside that container. And am applying some matrix transform to my text box and image in order to zoom it.
tb.RenderTransform = new MatrixTransform(m);
But now the text box is getting moved to different position. But It should get zoomed along with the image. How to achieve that.?
I'm new on Windows development and more in Windows Phone Development.
I'm trying to create a grid view composed of three cell.
Each grid view are composed of one image (for the background) and a textblock.
My background image is a cloud image and I want the first image partialy hidden by the second one and the second one partially hidden by the third one.
I tried to play with the margin of the cell for the y part, that's works but my cloud image doesn't make the entire width of my cell. So I tried the "UnifirmToFill" option but my images are cropped...
On iOS development in this case we can use the magic property "ClipToBounds", everywhere I saw the answer "use the clip to bounds property" but apparently this property is a legend or Visual Studio lie me...
Do you have an idea to resolve my problem ?
Thank you in advance!
To resume:
If I use the "uniformToFill" stretch option, my image is zoomed. It is ok for me.
But there is a way to display the cropped part? I want my image zoomed and displayed out the cell view.
In XAML there are four possible Stretch options:
None
The image is shown in it's original size. If its larger than the parent element, it'll only show the top left portion of the image that fits inside. If the image is smaller than the parent element, then it's shown in it's entirety.
Fill
The image is resized to fill the parent element. If the aspect ratios are different, then the image will be stretched to fit the parent. This will distort the image.
Uniform
The image will be scaled up as large as it can be, while still being completely inside of the parent. Unlike Fill which will stretch the image to make it fit perfectly, Uniform will keep the aspect ratio of the image and stop scaling when it reaches the bounds of the parent.
UniformToFill
This is the bastard child of the previous two. It will scale the image, while keeping the aspect ratio, until it fills the parent element. This means that some parts of the image will be clipped if the aspect ratios are different.
For more information on the Stretch enumeration, hit it up on MSDN
UPDATE
If you want to show the image outside of the bounds of the parent you could do something like this:
<Grid Width="100" Height="50">
<Grid.Clip>
<RectangleGeometry Rect="0 0 100 50"/>
</Grid.Clip>
</Grid>
This was suggested here on SO
I am writing a WPF app that displays an image that is initially centered. The user can zoom in/out and move the image, which are implemented using ScaleTransform and TranslateTransform. That works great.
The problem is when the image is significantly bigger than the window, and the user moves the image or zooms out enough so that the entire image should be visible. The portion of the image that was originally hidden isn't rendered, and instead only the originally viewable part of the image is drawn.
Based on some other questions, if I put my image inside of a Canvas that will cause the entire image to be rendered, and when moved it will be rendered correctly. The problem is that I don't want my image to be in a Canvas, since that prevents any other layout from occurring - the HorizontalAlignment and VerticalAlignment properties are ignored (so the image is no longer centered), and I need to implement an option that will draw the image as large as possible to fill the entire area of the window which no longer works (setting the Stretch property to UniformToFill doesn't do anything).
Currently the two transforms are set to the RenderTransform property. If I use LayoutTransform instead, the entire image is drawn, but this also prevents the user from moving any portion of the image off the edge of the window (which is behavior that I would like to keep).
How can I tell WPF to always render the entire image without using a Canvas or a LayoutTransform?
I suggest not using a TranslateTransform but instead rely on the ScrollViewer.
<ScrollViewer>
<Grid>
<Image Source="blabla">
<Image.LayoutTransform>
<ScaleTransform />
</Image.LayoutTransform>
</Image>
</Grid>
</ScrollViewer>
The ScrollViewer gives the Image infinite space to expand, the entire image will be rendered. The Grid forces a centered layout while still allowing the image to expand. If you don't like the scrollbars to control the translate then you can hide them and roll your own solution.
LayoutTransform is definetely the way to go, so that the image's actual size in pixels (based on the zoom) is properly reflected onto your window.
I'm trying to add a zoom feature for an image viewer control I'm creating. When viewing the image, holding down the left mouse button brings up a rounded rectangle that is zoomed into the image. I figure I can use An ImageBrush as the background but I can't figure out how to make it just display a specified area of the image. Can this even be done?
By using the Viewbox.
The application will have a menu strip on top and the rest will display lines and shapes. I want to be able to drag and pan the main display area by clicking it and dragging it in any direction.
I am currently drawing items using pixel values (for example a line drawn from (1042,54)to(1240,104). But I think a monitor with a smaller resolution will not be able to display that object. That is why I want to be able to pan the display area.
The lines and shapes are currently being drawn on a gird that I placed inside the window.
If you place the canvas inside a ScrollViewer then if the canvas is larger than the application window it will be displayed with scroll bars.
You can then address points on the canvas with values relative to the canvas rather than the screen.