Step 3 of 4: Adding Code for Image Cropping

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The code in this step will load the default image and allow the user to crop it.
Follow these steps:

Open the MainPage.xaml.cs file and add the following using (Imports in Visual Basic) statements.

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using C1.Xaml; using C1.Xaml.Imaging; using System.IO;

Add the following code to load a default image and define cropping:

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public partial class MainPage : UserControl { C1Bitmap bitmap = new C1Bitmap(); Rect selection; public MainPage() { InitializeComponent(); LoadDefaultImage(); image.Source = bitmap.ImageSource; var mouseHelper = new C1DragHelper(imageGrid); mouseHelper.DragStarted += OnDragStarted; mouseHelper.DragDelta += OnDragDelta; } void OnDragDelta(object sender, C1DragDeltaEventArgs e) { var transform = Window.Current.Content.TransformToVisual(image); var start = transform.TransformPoint(_startPosition); var end = transform.TransformPoint(e.GetPosition(null)); start.X = Math.Min((double)Math.Max(start.X, 0), bitmap.Width); end.X = Math.Min((double)Math.Max(end.X, 0), bitmap.Width); start.Y = Math.Min((double)Math.Max(start.Y, 0), bitmap.Height); end.Y = Math.Min((double)Math.Max(end.Y, 0), bitmap.Height); selection = new Rect(new Point( Math.Round(Convert.ToDouble(Math.Min(start.X, end.X))), Math.Round(Convert.ToDouble(Math.Min(start.Y, end.Y)))), new Size(Convert.ToDouble(Math.Round(Math.Abs(start.X - end.X))), Convert.ToDouble(Math.Round(Math.Abs(start.Y - end.Y))))); UpdateMask(); } void UpdateMask() { topMask.Height = selection.Top; bottomMask.Height = bitmap.Height - selection.Bottom; leftMask.Width = selection.Left; rightMask.Width = bitmap.Width - selection.Right; } void LoadDefaultImage() { Assembly asm = typeof(Crop).GetTypeInfo().Assembly; Stream stream = asm.GetManifestResourceStream("ImageSamplesLib2012.Resources.Lenna.jpg"); LoadImageStream(stream); } void LoadImageStream(Stream stream) { bitmap.SetStream(stream); imageGrid.Width = bitmap.Width; imageGrid.Height = bitmap.Height; selection = new Rect(0, 0, bitmap.Width, bitmap.Height); UpdateMask(); } }

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public partial class MainPage : UserControl
    {
        C1Bitmap bitmap = new C1Bitmap();
        Rect selection;

        public MainPage()
        {
            InitializeComponent();
            LoadDefaultImage();
            image.Source = bitmap.ImageSource;
            var mouseHelper = new C1DragHelper(imageGrid);
            mouseHelper.DragStarted += OnDragStarted;
            mouseHelper.DragDelta += OnDragDelta;
        }
        void OnDragDelta(object sender, C1DragDeltaEventArgs e)
        {
            var transform = Window.Current.Content.TransformToVisual(image);
            var start = transform.TransformPoint(_startPosition);
            var end = transform.TransformPoint(e.GetPosition(null));
            start.X = Math.Min((double)Math.Max(start.X, 0), bitmap.Width);
            end.X = Math.Min((double)Math.Max(end.X, 0), bitmap.Width);
            start.Y = Math.Min((double)Math.Max(start.Y, 0), bitmap.Height);
            end.Y = Math.Min((double)Math.Max(end.Y, 0), bitmap.Height);
            selection = new Rect(new Point(
                Math.Round(Convert.ToDouble(Math.Min(start.X, end.X))),
                Math.Round(Convert.ToDouble(Math.Min(start.Y, end.Y)))),
                new Size(Convert.ToDouble(Math.Round(Math.Abs(start.X - end.X))),
                    Convert.ToDouble(Math.Round(Math.Abs(start.Y - end.Y)))));
            UpdateMask();       
}
        void UpdateMask()
        {
            topMask.Height = selection.Top;
            bottomMask.Height = bitmap.Height - selection.Bottom;
            leftMask.Width = selection.Left;
            rightMask.Width = bitmap.Width - selection.Right;
        }
       
        void LoadDefaultImage()
        {
            Assembly asm = typeof(Crop).GetTypeInfo().Assembly;
            Stream stream = asm.GetManifestResourceStream("ImageSamplesLib2012.Resources.Lenna.jpg");
            LoadImageStream(stream);
        }
       void LoadImageStream(Stream stream)
        {
            bitmap.SetStream(stream);
           
            imageGrid.Width = bitmap.Width;
            imageGrid.Height = bitmap.Height;
            selection = new Rect(0, 0, bitmap.Width, bitmap.Height);
            UpdateMask();
        }
    }

In the next step you will run the application.