Hi,
I have an application where I use EntityFramework (MSSQL database ) to show the attribute table of data with a geometry column. this geometry column contains (multi) polygons .
I want to show a “miniature” image / svg / png of the polygon / shape in a row or detail view in my application.
I have not been able to do this with Aspose.Gis.
What I was expecting was that I can use Aspose.Gis to instanciate a Aspose.Gis.Feature.Geometry and then just have to say … Feature.ToSVG or Feature.ToPNG to get the image or svg data. base64 data is also ok and usable in a tabular form.
image.png (3.9 KB)
how can I do this with Aspose.Gis
Hope you can guide
Regards.
MC
@mcanavar,
We will evaluate your requirements and get back to you soon.
@mcanavar,
Please notice, we have logged an investigation ticket with an id “GISNET-1326” for your task/issue. We will evaluate and look into the details of your requirements.
Once we have an update on it, we will let you know here.
1 Like
This is actually a very usefull functional addition to generate SVG or PNG of the geometry with a given width and height.
I’m not asking for a timeline , but wanted to bring this issue to your attention again .
Hi, @mcanavar
As a workaround, you need to create a new layer (in memory using some driver) and put the geometry there. Next step, you can draw this layer on a map.
We plan to create an extension to hide this implementation. if you still have questions, let me know
Hi, @mcanavar
The Ticket (GISNET-1326) have been completed in Aspose.GIS for .NET 22.05 . Please feel free to contact us if you have any other issues or difficulty using the product.
1 Like
Hi @Evgeniy.Timofeev,
Thank you for implementing this request.
I have been able to stream and export to file using different renderers with one line. like this:
geometry.AsImage(filenamepath, new Measurement(200, Unit.Pixels), new Measurement(200, Unit.Pixels), Renderers.Png);
and
var imageStream = geometry.AsImage(new Measurement(200, Unit.Pixels), new Measurement(200, Unit.Pixels), Renderers.Png);
This is great!
Only issue I’m now having is that I’m not able to determine the color of the renderd shape, how can I set the line and fill color of the shape . I’m working with Crop fields and each color represent the crop on that field .
One example of a png file renderd is attached.13608.png (1.9 KB)
1 Like
@mcanavar,
We will check and get back to you soon.
1 Like
Hi, @mcanavar
Please consider code below to determine the color of the rendered shapes, lines, points
//use to write in stream
var imageStream = new MemoryStream();
AbstractPath path = AbstractPath.FromStream(imageStream);
//use to write in file
//AbstractPath path = AbstractPath.FromLocalPath(outputPath);
// styles
var lineSymbolizer = new SimpleLine { Width = 1.5, Color = Color.DarkSlateBlue };
var polygonSymbolizer = new SimpleFill { FillColor = Color.Azure, StrokeColor = Color.Brown };
var pointSymbolizer = new SimpleMarker { FillColor = Color.Aqua, StrokeColor = Color.Red };
var symbolizer = new MixedGeometrySymbolizer();
symbolizer.LineSymbolizer = lineSymbolizer;
symbolizer.PointSymbolizer = pointSymbolizer;
symbolizer.PolygonSymbolizer = polygonSymbolizer;
// render
geometry.AsImage(this, path, Measurement.Pixels(200), Measurement.Pixels(200), Renderers.Png, symbolizer);
All feature to render: Symbology|Documentation (aspose.com)
Thanks
1 Like
Hi @Evgeniy.Timofeev,
This is what I was looking for, thank you for the example .
Apologies that I overlooked the thirt override of the AsImage function with the symbolizer property.
Kind Regards,
Mehmet
PS: Perhaps the property symbolizer of the AsImage function should be optional for or all three of the override function . .
Hi, @mcanavar
The symbolizer property has been added in all methods. The Ticket ( GISNET-1335) has been completed in Aspose.GIS for .NET 22.06 . Please feel free to contact us if you have any other issues or difficulty using the product.
1 Like
Hi,
I want to visualize as set of geometries in a collection and want to give each item in the collection their own color for border and fill and render this to memory stream. / png.
something like this ?
using System;
using Aspose.Gis;
using Aspose.Gis.Geometries;
using Aspose.Gis.Rendering;
namespace GeometryCollectionVisualization
{
class Program
{
static void Main(string[] args)
{
// Create a new map instance
var map = new Map();
var layer = map.AddLayer();
// Create a geometry collection with different geometries
var geometryCollection = new GeometryCollection
{
new Point(10, 20),
new LineString(new[] {new Point(30, 40), new Point(50, 60)}),
new Polygon(new[]
{
new[]
{
new Point(70, 80),
new Point(90, 100),
new Point(110, 120),
new Point(70, 80)
}
})
};
// Define colors for each geometry
var colors = new[] {Color.Red, Color.Green, Color.Blue};
// Visualize each geometry with its respective color
for (int i = 0; i < geometryCollection.Count; i++)
{
var style = new FeatureStyle
{
Fill = new SolidFill(colors[i])
};
// Create a feature and add it to the layer
var feature = layer.AddFeature(geometryCollection[i]);
feature.GeometryStyle = style;
}
// Render the map
var options = new MapImageOptions
{
Format = MapImageFormat.Png
};
map.Render("output.png", options);
}
}
}
can this be done ?
regards,
Mehmet
Hi, @mcanavar
Geometry styles are used for formats with inline styling. It doesn’t work for rendering.
To solve your problem, a solution using FeatureBasedConfiguration is suitable. See an example at this link Map Rendering to Image SVG, PNG, JPG using GIS C# Library|Documentation (aspose.com). You can change the color, and other style options depending on the content.
Best regards
Hi @Evgeniy.Timofeev,
Thank you for your suggestion, but I did not succeed with this.
I only use the abstract path and in memory rendering , so no file paths or files available .
I have a collection of IGeometry objects that I want to display and want to give each of the objects a color based on some value in Objects attributes (like the example for FeatureBasedConfiguration ).
Background layer to openstreetmap would be nice , but a blank background is also fine.
I keep getting errors like : the layer does not support read access or combine is not supported .
It seemed so simple to add features to a map with its own styling or a layer with features that can make use of a style sheet like SLD , but is not .
Regards,
Mehmet
Please try below code
using System.Drawing;
using Aspose.Gis.Geometries;
using Aspose.Gis.Rendering;
using Aspose.Gis;
using Point = Aspose.Gis.Geometries.Point;
using Aspose.Gis.Rendering.Symbolizers;
public string RenderGeometrySelfColor()
{
// Get available file name
var fileName = "output";
var fileExtension = ".png";
var availableFileName = fileName;
int j = 0;
while (System.IO.File.Exists(availableFileName + fileExtension))
{
availableFileName = fileName + j;
j++;
}
// Create a geometry collection with different geometries
var geometryCollection = new GeometryCollection
{
new Point(10, 20),
new LineString(new[] {new Point(30, 40), new Point(50, 60)}),
new Polygon(new LinearRing(new[] {new Point(70, 80), new Point(110, 120), new Point(100, 120), new Point(70, 80)}))
};
// Define colors for each geometry
var colors = new[] { Color.Red, Color.Green, Color.Blue };
// Create in memory layer to map each geometry with its respective color
var layer = Drivers.InMemory.CreateLayer();
layer.Attributes.Add(new FeatureAttribute("Color", AttributeDataType.Integer));
for (int i = 0; i < geometryCollection.Count; i++)
{
// Create a feature and add it to the layer
var feature = layer.ConstructFeature();
feature.SetValue("Color", colors[i].ToArgb());
feature.Geometry = geometryCollection[i];
layer.Add(feature);
}
// Create a new map instance
using (var map = new Aspose.Gis.Rendering.Map(200, 200))
{
map.Padding = 5;
var pointSymbolizer = new SimpleMarker
{
FeatureBasedConfiguration = (feature, symbolizer) =>
{
int color = feature.GetValue<int>("Color");
symbolizer.FillColor = Color.FromArgb(color);
}
};
var lineSymbolizer = new SimpleLine
{
FeatureBasedConfiguration = (feature, symbolizer) =>
{
int color = feature.GetValue<int>("Color");
symbolizer.Color = Color.FromArgb(color);
}
};
var poligonSymbolizer = new SimpleFill
{
FeatureBasedConfiguration = (feature, symbolizer) =>
{
int color = feature.GetValue<int>("Color");
symbolizer.FillColor = Color.FromArgb(color);
}
};
map.Add(layer, new MixedGeometrySymbolizer() { PointSymbolizer = pointSymbolizer, LineSymbolizer = lineSymbolizer, PolygonSymbolizer = poligonSymbolizer });
map.Render(availableFileName + fileExtension, Renderers.Jpeg);
}
return availableFileName + fileExtension;
}
Best Regards
1 Like
Hi @Evgeniy.Timofeev,
Thank you for your input , I see where I went wrong 
.
I have tweaked your code a bit at the end; and used a abstract path to render the result to a imagestream to use this without having to save to file first.
var imageStream = new MemoryStream();
AbstractPath path = AbstractPath.FromStream(imageStream);
//map.Render(availableFileName + fileExtension, Renderers.Png);
map.Render(path, Renderers.Png);
var byteArray = imageStream.ToArray();
var bytes = Convert.ToBase64String(byteArray);
retPng = String.Format("data:image/png;base64,{0}", bytes);
Thank you again, this helped me a lot .
Regards,
Mehmet
1 Like