[Mono-list] Re: Direct DBF Access?

[Abe Gillespie]

I couldn't find what I wanted so I created my own ... this code relies
heavily on the monoGIS project.  Depends on the ShapeLib library.  No
warranty, blah, blah.   Also, no comments.  :)  Enjoy.

-Abe

using System;
using System.Runtime.InteropServices;
using System.Text;
using System.IO;


public enum DbfFieldType

{

	String,

	Integer,

	Double,

	Logical,

	Invalid	

};

public class CShapeLib
{
	[DllImport("shapelib.dll", CharSet=CharSet.Auto)]
	public static extern IntPtr DBFOpen(string szDBFFile, string szAccess);


	[DllImport("shapelib.dll", CharSet=CharSet.Auto)]

	public static extern int DBFGetFieldCount(IntPtr hDBF);


	[DllImport("shapelib.dll", CharSet=CharSet.Auto)]

	public static extern DbfFieldType DBFGetFieldInfo(IntPtr hDBF, int iField,
		StringBuilder pszFieldName, ref int pnWidth, ref int pnDecimals);
		
	[DllImport("shapelib.dll", CharSet=CharSet.Auto)]

	public static extern void DBFClose(IntPtr hDBF);
}

public class CDbfInfo : IDisposable
{
	private IntPtr m_hDbf = IntPtr.Zero;
	private IntPtr dbfHandle {get {return m_hDbf;}}

	private int m_fldCnt;
	public int fieldCount {get {return m_fldCnt;}}

	public CDbfInfo(FileInfo dbfFileInfo)
	{
		m_hDbf = CShapeLib.DBFOpen(dbfFileInfo.FullName, "rb");
		m_fldCnt = CShapeLib.DBFGetFieldCount(dbfHandle);
	}

	public void Dispose()
	{
		CShapeLib.DBFClose(dbfHandle);
	}

	public CDbfField getField(int index)
	{		
		if (index < 0 || index >= fieldCount)
			throw new IndexOutOfRangeException();

		return new CDbfField(dbfHandle, index);
	}
}

public class CDbfField
{
	internal CDbfField(IntPtr hDbf, int index)
	{
		StringBuilder sb = new StringBuilder(20);
		int w = -1;
		int decs = -1;
		DbfFieldType t = CShapeLib.DBFGetFieldInfo(hDbf, index, sb, ref w, ref decs);
		
		m_type = t;
		m_idx = index;
		m_name = sb.ToString();
		m_w = w;
		m_decs = decs;
	}

	private DbfFieldType m_type;
	public DbfFieldType type {get {return m_type;}}

	private int m_idx;
	public int index {get {return m_idx;}}

	private string m_name;
	public string name {get {return m_name;}}

	private int m_w;
	public int width {get {return m_w;}}
	
	private int m_decs;
	public int decimals {get {return m_decs;}}
}


On 11/30/05, Abe Gillespie <abe.gillespie at gmail.com> wrote:
> Anyone have a way to access DBF files w/o going through ADO.NET (and
> as far as I can tell this option's only available on Windows going
> through an ODBC connection)?  Specifically, I only really need header
> access to inspect the table structure.
>
> There is this:
> http://www.c-sharpcorner.com/Code/2002/Feb/xBaseEngineRFV.asp
>
> But it's managed C++.  I guess, theoretically I could compile it in
> Windows and use it in Linux ... but I'd rather not if there's another
> option.
>
> Thanks for the help!
> -Abe
>