How to Add Field to a Shapefile Using DotSpatial

Question

I tried a lots on Google to find a sample of showing how to add a Field to attribute table of an existing shapefile. For example I have a Shapefile at

C://data/Streets.shp

and need to add two field L_CITY and R_CITY both text and 50 characters limit. Can you please let me know how to do this in DotSpatial?

Answer 1

You would need to access the attribute table of the Shapefile, then get the column collection and add a new one:

static void AddColumn()
{
    string sf_name = @"C:\temp\a.shp";

    //Open
    Shapefile sf = Shapefile.OpenFile(sf_name);

    //Create the new column (name + type)
    DataColumn newCol = new DataColumn("colName", typeof(string));
    //Add the length restriction
    newCol.MaxLength = 50;

    //Add the new column to the attribute table.
    sf.Attributes.Table.Columns.Add(newCol);

    // save in the current shapefile
    sf.Save();

    //Or save in a new one
    sf.SaveAs(@"C:\temp\a_copy.shp", true);
}