public static void Merge(string[] SourceFiles, string targetFile, BackgroundWorker worker, DoWorkEventArgs e)
        {
            File.Copy(SourceFiles[0], targetFile, true);
            ShpFile outFile = new ShpFile(targetFile, ShapeFileOpenMode.FileReadFirst);

            for (int i = 1; i < SourceFiles.Length; i++)
            {
                ShpFile mergeFile = new ShpFile(SourceFiles[i], ShapeFileOpenMode.FileRead);
                outFile.Merge(mergeFile);
                mergeFile.Close();
                int percentComplete = (int)((float)(i + 1) / (float)SourceFiles.Length * 100);
                worker.ReportProgress(percentComplete);
                if (worker.CancellationPending)
                {
                    e.Cancel = true;
                    outFile.Close();
                    return;
                }
            }
            outFile.Close();
        }
        public static void  Merge(string[] SourceFiles, string targetFile)
        {
            File.Copy(SourceFiles[0], targetFile, true);
            ShpFile outFile = new ShpFile(targetFile, ShapeFileOpenMode.FileReadFirst);

            for (int i = 1; i < SourceFiles.Length - 1; i++)
            {
                ShpFile mergeFile = new ShpFile(SourceFiles[i], ShapeFileOpenMode.FileRead);
                outFile.Merge(mergeFile);
            }
            outFile.Close();
        }