CODEWITHSUNDEEP
xamlwindows-runtimewindows-store-appswinrt-xaml
micahhoover
micahhoover

Reputation: 2160

XAML: accessing actual width and height

I have a viewbox with an image inside:

<Viewbox MaxHeight="100" MaxWidth="100" x:Name="Scenario4ImageContainer2" Stretch="Uniform" Grid.Column="1" Grid.Row="1">
    <Image x:Name="Scenario4Image" PointerPressed="Scenario4Image_PointerPressed" HorizontalAlignment="Stretch"  />
</Viewbox>

I want to be able to grab the actual width/height values, but when I try this in the backend C#:

int w = (int)Scenario4ImageContainer.Width

I get an error saying the parameter is incorrect.

This goes away if I hardcode the width, but I want it to resize dynamically.

I also tried grabbing Scenario4ImageContainer.ActualWidth but this parameter was "incorrect" as well.

Upvotes: 1

Views: 1097

Answers (3)

micahhoover
micahhoover

Reputation: 2160

On every draw I do a quick check to see if the container size has changed (with an initialization of 0 at the beginning to make sure it catches the first time).

if (containerWidth != Output.ActualWidth - 300)
{
    Scenario4ImageContainer.Width = Output.ActualWidth - 300;
    Scenario4ImageContainer.Height = Output.ActualHeight - 20;
    containerWidth = Output.ActualWidth - 300;
}

It works for the most part, but when the class gets navigated out and navigated back it has a problem for some reason. Probably unrelated.

Upvotes: 0

ixSci
ixSci

Reputation: 13698

Seems like I've found the event you need to handle: you should handle ImageOpened event. It is because image is retrieved asynchronously and if try to handle any other event there is a good chance to not have image loaded at that time so actual size is zero

Upvotes: 1

Hermit Dave
Hermit Dave

Reputation: 3046

A while back I was trying to measure width of a string. You can try a similar mechanism to get dimensions.

http://invokeit.wordpress.com/2012/09/19/how-to-measure-rendered-string-dimensions-in-win8dev/

this.tb.FontSize = 20;
this.tb.Measire(new Size(400, 300)); // assuming that 400x300 is max size of textblock you want
double currentWidth = this.tb.DesiredSize.Width;
double currentHeight = this.tb.DesiredSize.Height;

Upvotes: 1

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