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Updated Wiki: ReadProj4Strings

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Sample code that demonstrates how to read a prog4 string and then project a point

C# Code

using DotSpatial.Projections;

        //Code that allows the user to input a Proj4 string and reproject a WGS 1984 GCS to a Proj4 PCSprivatevoid btnProjection_Click(object sender, EventArgs e)
        {
            //Declares a new ProjectionInfo and sets it to GCS_WGS_1984
            ProjectionInfo pStart = new ProjectionInfo();
            pStart = KnownCoordinateSystems.Geographic.World.WGS1984;
            //Declares a new ProjectionInfo and allows the user to directly input a Proj4 sring
            ProjectionInfo pEnd = ProjectionInfo.FromEsriString("+proj=aea +lat_1=20 +lat_2=-23 +lat_0=0 +lon_0=25 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs ");
            //Declares the point to be project, starts out as 0,0double[] xy = newdouble[2];
            double[] z = newdouble[1];
            //calls the reproject function and reprojects the points
            Reproject.ReprojectPoints(xy, z, pStart, pEnd, 0, 1);
            MessageBox.Show("Reprojection is compelte.");          
        }      


VB.net Code

Imports DotSpatial.Projections

'Code that allows the user to input a Proj4 string and reproject a WGS 1984 GCS to a Proj4 PCSPrivateSub btnProjection_Click(sender AsObject, e As EventArgs)
	'Declares a new ProjectionInfo and sets it to GCS_WGS_1984Dim pStart AsNew ProjectionInfo()
	pStart = KnownCoordinateSystems.Geographic.World.WGS1984
	'Declares a new ProjectionInfo and allows the user to directly input a Proj4 sringDim pEnd As ProjectionInfo = ProjectionInfo.FromEsriString("+proj=aea +lat_1=20 +lat_2=-23 +lat_0=0 +lon_0=25 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs ")
	'Declares the point to be project, starts out as 0,0Dim xy AsDouble() = NewDouble(1) {}
	Dim z AsDouble() = NewDouble(0) {}
	'calls the reproject function and reprojects the points
	Reproject.ReprojectPoints(xy, z, pStart, pEnd, 0, 1)
	MessageBox.Show("Reprojection is compelte.")
EndSub

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