In WPF InkCanvas, ink is rendered on top and strokes don't have z-index property. I have other UIElements like shape, images on InkCanvas and can't bring UIElements to top. Is there any work around for this problem. I have tried
below things.
1) use two different InkCanvas (one for strokes & one for UIElements)
- Can't achieve sandwich effect in this (i.e. UIElement between strokes
Something like this in this circle is UIElement
2) Masking strokes using geometry path and add as UIElement
- If I add strokes as UIElements (using path) then I will loose erase functionality.
The map editor which is part of our game suite uses ink to draw terrain so I have recent experience of this sort of thing.
The way my app works is you select a thing you're drawing ( woods, road, contour etc ) and draw a stroke using ink.
I then process that stroke and obtain a geometry.
I pass that to a viewmodel > itemssource > itemscontrol.
This is then templated into a piece of terrain.
This itemscontrol is below the inkcanvas.
The user can manipulate the z-index of those by moving them up and down in the observablecollection.
I rely on just the order to define z-index.
I also retain the data from each stroke by serialising it.
You're thinking "how about erase?".
To do that I'd have an explicit erase-this-thing mode.
Let them pick a shape and get it's stroke data, add the stroke back to the inkcanvas. Once they finish erasing then use a "save changes" button or something to re-process the stroke(s) and switch back to edit mode.
Since this is a game map editor I'm working on, drawing produces area and line types of terrain but their area/line is defined by a geometry translated from a stroke. ZIndex corresponds to the order of objects in the left panel. The buttons you can see with the chevrons pointing up and down move the order of a
Is there a built-in control that allows the user to grab the drag points on the corners and/or sides to resize an Image in a FlowDocument? It's common functionality, but I can't find it or any reference on how to implement it.
I'm trying to drag and drop (slide) a Silverlight element from one part of a window to another.
I've implemented the MouseLeftButtonDown, MouseMove, and MouseLeftButtonUp event handlers on the element, but I've run into a bit of a problem.
All of the examples I've seen involve moving the element by setting the Canvas.Left and Canvas.Top properties. None of the elements I'm trying to manipulate live inside a Canvas. Is there a way to set the absolute position of the element being dragged, based on the coordinates of the mouse? Or is there a prepackaged solution to this problems somewhere that I've missed?
All panels but Canvas use some kind of constraint to position their children. Only Canvas lets you use absolute positioning. That's why I think it is the only way to implement drag and drop .
Feel free to use a Canvas on top of your existing panel. Just remember to remove the dragged element from its original parent and put it in the Canvas (or drag some kind of copy) and do the reverse on mouse up.
One way of achieving absolutely positioning an item inside any container, not only Canvas, is to use transformation instead of Left/Top properties. For instance, to set at Left=50 Top=80 you can modify the margin values through transformation.
In a Silverlight application I have large images which have flow charts on them.
I need to handle the clicks on specific hotspots of the image where the flow chart boxes are.
Since the flow charts will always be different, the information of where the hotspots has to be dynamic, e.g. in a list of coordinates.
I've found article like this one but don't need the detail of e.g. the outline of countries but just simple rectangle and circle areas.
I've also found articles where they talk about overlaying an HTML image map over the silverlight application, but it has to be easier than this.
What is the best way to handle clicks on specific areas of an image in silverlight?
Place the Image and a Canvas in a Grid so that the Canvas overlays the Image.
Add shapes of appropriate sizes and placed as needed to the canvas. All shapes will a transparent fill and no border, hence the user only sees the Image. On the Canvas MouseDown (or Up events) use OriginalSource to determine which shape generated the click. Use the Tag property of each shape to associate it with some object that represents the flowchart element being mapped.
I found an easy way to do this without a canvas:
How to get the coordinates of an image mouse click in the event handler?
I would like to understand the general requirements for WPF/Silverlight layout for making it possible to implement pan&zoom (drag and zoom) features. I don't mean pan&zoom for an image but for a total page (window) layout (or part of it) with some controls.
What features of the layout and what features of used custom controls make layout fixed and pan&zoom impossible?
General rule
With few exceptions, everything in WPF can be panned, zoomed, rotated, stretched, etc to your heart's content. This include single controls like Button, compound controls like ListBox, and containers like StackPanel.
The exceptions
Here are the exceptions:
If you are using Adorner and your AdornerDecorator is outside the panned/zoomed area, then the Adorners attached to your panned/zoomed area will pan but not zoom. The solution is to put an additional AdornerDecorator inside the panned/zoomed area.
If you use a Popup, it will display at the panned/zoomed location of its PlacementTarget but it will not itself be scaled. It will also not move as you pan the area containing its PlacementTarget (basically it sits in its own surface above the target control). To get around this, use a zero-size Canvas with high Z order instead when you want something to pop up within the zoom/pan area.
Any ContextMenu you define will be shown inside a popup, so the menu items will display normal size even when the area you clicked on is zoomed in or out. Because of the nature of a context menu, this is probably desirable behavior. If not, you can wrap the menu items in a ViewBox and tie the zoom to your main area's zoom.
Your ToolTips will display normal size even if the UI is panned or zoomed. Same solution as for ContextMenu.
If you used WinForms integration to integrated legacy WinForms controls and UI, they will not properly pan, zoom and clip in certain situations. There is an advanced technique for working around this, where you implement the WinForms control off-screen, then using BitBlt or similar copy the image into your window as an image, and forward mouse clicks and keystrokes to the offscreen window. This is a lot of work, though.
If you bypass WPF and directly use GDI+ or DirectX, or use Win32 hWnds to display content or UI, that content or UI will not be properly panned, zoomed or clipped to the window unless you do it yourself in your interface code.
Final notes
A good WPF UI always uses panels like Grid, DockPanel, etc to lay out controls in a flexible manner so they automatically adjust to container sizes, rather than using fixed sizes and positions. This is also true for the internal contents of your pan/zoom area as well, BUT there is an exception to this rule: the outermost element in your pan/zoom area must have a specified size. Otherwise what will define the area being panned/zoomed over?
The easy way to implement pan/zoom capabilities is to adjust the RenderTransform of the outermost control in your pan/zoom area. There are many different ways to implement controls for panning and zooming, for example you could use toolbar buttons and sliders, scroll bars, mouse wheel, spacebar+drag to pan, draggable areas of panned UI itself, or any combination of these. Whichever interface you choose, just have it update the RenderTransform appropriately from the code-behind and you're good to go.
If your chosen panning mechanism is scroll bars, you might want to use a ScrollViewer and only use the RenderTransform for the zoom.
Be sure you set clipping on the pan/zoom area. Otherwise if you zoom in or pan items off the side, they will still be visible outside the pan/zoom area.
Use a MultiScaleImage or Canvas area, and place everything you need to pan and zoom in it
<Canvas x:Name="panZoomPanel" Background="Transparent">
</Canvas>
In code use make a TranslateTransform and a ScaleTransform in a TransformGroup to pan and zoom
Check out other SO post or this example or this one
In general you can treat any composite set of UI elements the same as you would treat a single UIElement so the case of an image isn't really different than doing the same for an entire application. The best way to handle zooming based on user input (as opposed to automatic scaling that Viewbox does) is applying a ScaleTransform. This can be set on a high level parent element, like a Grid at the root of a Window layout. For panning you can combine in a TranslateTransform or in some cases use a ScrollViewer to handle moving the view of the content.
One really easy way of implementing zoom in XAML is to use a Silverlight ViewBox. This zooms the XAML not the pixels. You can specify the stretch to use and the ViewBox will scale based on this (Fill, None, Uniform etc). There are some great Viewbox blog posts on the web if you search for Silverlight+Viewbox on Google.
The panning is easily accomplished with a similar mechanism to drag and drop and there are also numerous how-to blog posts on this, available via Google. Just amounts to capturing MouseDown, MouseMove and MouseUp events.