Creation of multiple text files using C# in Visual Studio from DGView data

Question

Hi all I am having the following results in my data grid view, I want to print these data to multiple text files.

Text files should be in the format that it should start with 1stLine(Column Value Please see the image) and end at LastLine(Column Value Please see the image).

consider filename1 column value as the filename of that file.

likewise, I want to create multiples files. I am not sure to create multiple files based on the range.

            private void Create_Click(object sender, EventArgs e)
    {
        int FileStart = 0;
        int FileEnd = 0;
        string FileName = "";
        String MyDir = "C:\\Test\\";
        StringBuilder builder = new StringBuilder();
        int rowcount = DGV.Rows.Count;
        int columncount = DGV.Columns.Count;
        for (int fn = 0; fn < rowcount - 1; fn++)// fro running down all rows
        {

                if (string.IsNullOrEmpty(DGV.Rows[fn].Cells[0].Value.ToString()) == false) //checking for the filename                  
               {
                    FileName = DGV.Rows[fn].Cells[0].Value.ToString();
                    builder.Clear();

                    FileStart = fn;

                if (string.IsNullOrEmpty(DGV.Rows[fn].Cells[4].Value.ToString()) == false) // this is where i tried to check the last line
                {
                    for (int row = fn; row < rowcount - 1; row++)
                    {
                        FileEnd = row;                                             
                    }
                }

                    for (int i = FileStart; i < rowcount - 1; i++) // here start generating the file based on first and last line .. but as of now i took rowcount as last line.. if i put last line returns nothing...i know this is where i am wrong, but i tried lot of options 
                    {
                        List<string> cols = new List<string>();
                        for (int j = 1; j < columncount; j++)
                        {
                            cols.Add(DGV.Rows[i].Cells[j].Value.ToString());
                        }

                        builder.AppendLine(string.Join("\n", cols.ToArray()));

                        if (!Directory.Exists(MyDir))
                        {
                            Directory.CreateDirectory(MyDir);
                        }
                        System.IO.File.WriteAllText(MyDir + FileName, builder.ToString());
                        MessageBox.Show(@"Text file was created.");

                    }
                }
                else
                {
                    fn = fn + 1;
                }
            }
        }

Need output file like

Filename1

1stLine Bodytext1 BodyText2
Bodytext1 BodyText2
BodyText2 LastLine

Filename2

1stLine Bodytext1 BodyText2
Bodytext1 BodyText2
Bodytext1 BodyText2
Bodytext1 BodyText2
Bodytext1 BodyText2 LastLine

Filename3

1stLine Bodytext1 BodyText2
Bodytext1 BodyText2
Bodytext1 BodyText2
Bodytext1 BodyText2 LastLine

Answer 1

Below code breaks the DataGrid.DataSource Datatable into chunks that will go into each file.

private void SaveToFiles(DataTable srcData)
        {
            if (srcData.Rows.Count > 0)
            {
                int FileStart = 0;
                int FileEnd = -1;

                while (FileStart < srcData.Rows.Count)
                {
                    for (int row = FileStart; row < srcData.Rows.Count; row++)
                    {
                        if (string.IsNullOrEmpty(srcData.Rows[row].Field<string>(0)) == false)
                        {
                            FileStart = row;
                        }
                        if (string.IsNullOrEmpty(srcData.Rows[row].Field<string>(4)) == false)
                        {
                            FileEnd = row;
                            break;
                        }
                    }

                    var data = srcData.AsEnumerable().Skip(FileStart).Take(FileEnd - FileStart + 1);
                    SaveFile(data.ToList());
                    FileStart = FileEnd + 1;
                }
            }
        }

You need to add code to write the text to file in the format you wish - in place of the comment.

private void SaveFile(List<DataRow> fileData)
        {
            if (fileData != null && fileData.Count > 0)
            {
                string fileName = fileData[0].ItemArray[0].ToString();

                using (var fileStrm = File.Create(fileName + ".txt"))
                {
                    using (StreamWriter wrtr = new StreamWriter(fileStrm))
                    {
                       // handle writing to file here
                    }
                }
            }
        }

Answer 2

Sometimes it helps to write the algorithm down in words. Imagine you would need to do it by hand. How would the recipe of actions look like? Here is one example:

1) you start walking down all rows that you have. (for-all rows)

2) IF you encounter a non-empty item in column 1, you know that this is your starting point and you remember that value.

3) now you know that at the very same row there is the 1stLine value in column with the index 1. You take and remember that value as well.

4) now at this point you can start with your BodyText collection of values. start at the same row that you are and walk down the rows. In each row you take the value from column 2 and 3 then you check in column 4. IF it is empty you put a \n and the end of your line and continue with the next row doing the step 4 again. ELSE it means that you have reached the LastLine and you can now write the content that you have remembered into a file.

5) Now you would clear the memory of the last file, take the next row and continue with step 2

Hope that helps you to solve your problem. IF you have questions, just ask in a comment. Good Luck

EDIT:

Ok with you code at hand let's see:

1) It is useless to check for the last line before you start the second loop. If you look at step 4) of my algorithm you need to gather first the values from column 3 and 4 and AFTER that you check for the column 4!

if (string.IsNullOrEmpty(DGV.Rows[fn].Cells[4].Value.ToString()) == false)
    break; // This will cancel the inner loop and you return to the outer loop