Using ShapeFile (ESRI) Orientation Text

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Hi,

Using example of Esri ShapeFile, is it possible for the element List<MapVisualElement> to give an orientation text ?

Thanks for response

 

 

[Hristo]

Hi,

Thank you for writing.

The text of the map visual elements is painted using the System.Drawing.Graphics class and its DrawString method. By default, the text orientation is set to Horizontal. You can change this by creating a custom MapVisualElementFactory and change how the elements are painted: 

public class CustomMapVisualElementFactory : MapVisualElementFactory
    {
        public override MapVisualElement CreatePolygon(Collection<PointG> points)
        {
            CustomMapPolygon polygon = new CustomMapPolygon(points);

            return polygon;
        }
    }

    public class CustomMapPolygon : MapPolygon
    {
        public CustomMapPolygon(IEnumerable<PointG> points)
            : base(points)
        { }

        public override void Paint(IGraphics graphics, IMapViewport viewport)
        {
            if (string.IsNullOrEmpty(this.DrawText))
            {
                base.Paint(graphics, viewport);
                return;
            }

            List<GraphicsPath> paths = (List<GraphicsPath>)typeof(MapPolygon).GetField("paths", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(this);

            if (paths == null)
            {
                return;
            }

            StringFormat format = new StringFormat();
            format.Alignment = StringAlignment.Center;
            format.LineAlignment = StringAlignment.Center;

            foreach (GraphicsPath path in paths)
            {
                FillPrimitiveImpl fill = new FillPrimitiveImpl(this, null);
                fill.PaintFill(graphics, path, path.GetBounds());

                BorderPrimitiveImpl border = new BorderPrimitiveImpl(this, null);
                border.PaintBorder(graphics, null, path, path.GetBounds());

                Graphics g = (Graphics)graphics.UnderlayGraphics;
                System.Drawing.Drawing2D.GraphicsState state = g.Save();
                graphics.DrawString(this.DrawText, path.GetBounds(), this.Font, Color.Black, format, System.Windows.Forms.Orientation.Vertical, true);
                g.Restore(state);
            }
        }
    }

Then you can directly assign the factory to the static RadMapElement.VisualElementFactory property: 

RadMapElement.VisualElementFactory = new CustomMapVisualElementFactory();

I am also sending you attached my test project demonstrating the suggested approach.

I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo
Progress Telerik

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Thanks for response