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WPF Change data context on the fly

Hi,

problem:
Let's say I have trying to render the same wpf window and pass different data context one after the other for example a counter.

For example:

Window that shows counter.
I need to see the counter increment 1, then 2

var counter = new Counter(1);
DataContext = counter;
//force update & refresh

counter = new Counter(2);
DataContext = counter;
//force update & refresh

I'm new to WPF how can I do it? Do I need depency? or to fire and event?

Please submit full sample.

ASKER CERTIFIED SOLUTION

Ioannis Paraskevopoulos

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breezback

ASKER

Hey Giannis,

Thanks for your comment, my program doesn't have any buttons that are triggered.
How can I do it with no user interaction at all.

Ioannis Paraskevopoulos

How is this handled then? Do you have a timer or something? Can you provide some sample code.

breezback

ASKER

Let's say I have a command line that sends the counter "10"
The WPF should render 10 times, each time showing the counter.

For each render I need to do a snapshot with this code that is working:

private static void ExportAsImage(Fr<wbr ></wbr><wbr ></wbr>ameworkEle<wbr ></wbr>ment element, Counter counter)
        {

            element.DataContext = counter;
            var target = new RenderTargetBitmap((int)(7<wbr ></wbr><wbr ></wbr>20), (int)(620), 96, 96, PixelFormats.Pbgra32);
            target.Render(element);

            var encoder = new PngBitmapEncoder();
            var outputFrame = BitmapFrame.Create(target)<wbr ></wbr><wbr ></wbr>;
            encoder.Frames.Add(outputF<wbr ></wbr><wbr ></wbr>rame);

            var source = Guid.NewGuid().ToString("N<wbr ></wbr><wbr ></wbr>").Substri<wbr ></wbr>ng(0, 20) + ".png";
            using (var file = File.OpenWrite(source))
            {
                encoder.Save(file);
                //throw new Exception("done");
            }

        }

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As you can see, my DataContext is called Counter - and I need to catch each Render event to produce 10 snapshots. I don't mind to use a Timer but this counter can also be very big (500)

SOLUTION

breezback

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breezback

ASKER

Need the Timer to make it work