CODEWITHSUNDEEP
c#silverlightxaml
Erix
Erix

Reputation: 7105

Issues with getting some text centered in a Polygon

I'm creating a map in Silverlight that contains a bunch of rooms. All of the rooms are polygons, most of them are rectangles.

So what I'm doing is creating a Polygon using the x y point coordinates for the room. Something like 

Polygon p = new Polygon
p.points = pointCollection;
MainCanvas.Chilren.Add(p);

This works great. Next, I want to put the name of each room inside these on the map. I figured I'd just add a textblock child to the polygon. Unfortunately, it seems that UIElements cannot contain child UIElements. I think this is dumb, but whatever.

Next plan: Create a new Silverlight user control containing the polygon and a text field. Center text field in polygon within user control. So I just create one of these UserControls "Room" set the property "RoomShape" to the polygon and add it to the canvas. The problem here is that The Usercontrol is always added at position (0,0) and the room shape is in the bottom right position. What I really wanted was for the control to take on the size and shape of the polygon I add to it so I can find the center and add the text in. Is this possible?

Also, let's say I add a polygon to my layout in a control:

LayoutRoot.Children.Add(poly);

Why do 

poly.ActualHeight
poly.ActualWidth
poly.height
poly.width

all return 0 or NaN when I can clearly see them on the Canvas? And why do

Canvas.GetTop(poly);
Canvas.GetLeft(poly);

both return 0 when I can clearly see they are not located at (0,0)?

Any other suggestions for centering text in a polygon is appreciated.

Upvotes: 1

Views: 869

Answers (1)

danbord
danbord

Reputation: 4076

First of all, for sure you cannot add UIElements to Polygon. The Polygon is not a container so you can't add elements in it.

Second, if you want to set text in the middle of your polygon, why don't you wrap your polygon in a Grid. Then in the Grid, add your polygon, and your textblock like that :

<Grid x:Name="room1" Background="LightBlue" HorizontalAlignment="Center" VerticalAlignment="Center">
    <Polygon Stroke="Black" Fill="Beige">
        <Polygon.Points >
            <Point X="0" Y="0" />
               <Point X="20" Y="100" />
               <Point X="100" Y="50" />
               <Point X="0" Y="0" />
            </Polygon.Points>
         </Polygon> 
    <TextBlock VerticalAlignment="Center" HorizontalAlignment="Center">Room Name</TextBlock>   
</Grid>

Third, for the size always at 0, this is probably because you create/add the usercontrol at Load time. I know its sad but you will have to do the work in the UserControl_SizeChanged event of the container.

Upvotes: 2

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