Table of Contents

Import & export (CSV)

Read and write CSV/TSV files directly through the grid — no extra component required. Choose the delimiter and the start cell, control quoting and trimming, hook events for custom value parsing.

Overview

CSV support is built into the core grid (no TTMSFNCDataGridExcelIO needed):

Operation Method
Load CSV from file Grid.LoadFromCSVData(FileName)
Load CSV from stream Grid.LoadFromCSVStreamData(Stream)
Save CSV to file Grid.SaveToCSVData(FileName)
Save CSV to stream Grid.SaveToCSVStreamData(Stream)

The delimiter is controlled by Grid.Options.IO.Delimiter. When it is #0 (the default), the grid auto-detects the delimiter from the first two lines.

CSV sample data CSV sample data (dark theme)

Quick example

procedure TForm1.FormCreate(Sender: TObject);
begin
  // Where in the grid to drop the CSV content
  Grid.Options.IO.StartColumn := 1;
  Grid.Options.IO.StartRow    := 1;

  // Default delimiter is the system list separator. Override per call when needed.
  Grid.LoadFromCSVData('CARS.csv');
end;

procedure TForm1.SaveButtonClick(Sender: TObject);
begin
  // Save with explicit ; delimiter (regardless of OS locale)
  Grid.SaveToCSV('out.csv', ';');
end;

Step by step

1. Choose where the data lands

Grid.Options.IO.StartColumn := 1;      // skip the row-number column
Grid.Options.IO.StartRow    := 1;      // skip the header row

CSV is loaded into the rectangle starting at (StartColumn, StartRow) and growing right and down. Anything outside that rectangle is preserved.

Set MaxRows to stop loading after a maximum number of rows:

Grid.Options.IO.MaxRows := 10000;      // stop after 10 000 data rows

2. Load

Grid.LoadFromCSVData('CARS.csv');              // auto-detect delimiter

// Use a specific delimiter
Grid.Options.IO.Delimiter := ',';
Grid.LoadFromCSVData('CARS.csv');

// TAB-separated
Grid.Options.IO.Delimiter := #9;
Grid.LoadFromCSVData('CARS.tsv');

3. Save

Grid.Options.IO.Delimiter := ';';
Grid.SaveToCSVData('out.csv');

4. Quoting options

Control how the writer quotes cells:

Grid.Options.IO.AlwaysQuotes    := True;   // quote every cell, not just when needed
Grid.Options.IO.QuoteEmptyCells := True;   // write "" for empty cells

5. Trim spaces on import

Grid.Options.IO.TrimSpaces := True;        // strip leading/trailing whitespace

Useful when importing files that pad columns with spaces.

6. Auto-open after save

Grid.Options.IO.OpenAfterCreation := True;

When True, the grid asks the OS to open the saved file in its default handler immediately after writing.

7. Custom value parsing

The CSV reader infers types from the cell content. To override (e.g. parse "12,34" as a float, not a string), set Formatting.Type per column:

Grid.Columns[2].Formatting.&Type := gdftDateTime;
Grid.Columns[2].AddSetting(gcsFormatting);

8. Transform values during import or export

OnLoadCellData fires for every cell as it is read from the file, letting you replace or transform the raw string before it is stored. OnSaveCellData fires during save, letting you override what is written to the file:

// Import: parse a date string that uses a non-standard format
procedure TForm1.GridLoadCellData(Sender: TObject;
  AColumn, ARow: Integer;
  var AValue: TTMSFNCDataGridCellValue);
var
  D: TDateTime;
begin
  if AColumn = DateColumn then
  begin
    if TryStrToDateTime(AValue.AsString, D) then
      AValue := TValue.From<TDateTime>(D);
  end;
end;

// Export: write a custom label instead of the raw boolean value
procedure TForm1.GridSaveCellData(Sender: TObject;
  AColumn, ARow: Integer;
  var AValue: TTMSFNCDataGridCellValue);
begin
  if AColumn = StatusColumn then
  begin
    if AValue.AsBoolean then AValue := TValue.From<string>('Approved')
    else                     AValue := TValue.From<string>('Pending');
  end;
end;

Both events receive AColumn/ARow and AValue (a TTMSFNCDataGridCellValue = TValue) by reference — change AValue to override the stored or exported value.

9. Streaming for large files

For multi-million-row imports, prefer the stream variant and wrap it in BeginUpdate/EndUpdate for best performance:

Grid.Options.IO.Delimiter := ',';
var fs := TFileStream.Create('huge.csv', fmOpenRead);
try
  Grid.BeginUpdate;
  try
    Grid.LoadFromCSVStreamData(fs);
  finally
    Grid.EndUpdate;
  end;
finally
  fs.Free;
end;

Quoting and escaping

CSV reading honours the standard rules: fields containing the delimiter, double-quote, or newline are quoted, with embedded quotes doubled. The writer follows the same convention.

  • Grid.LoadFromCSVData(FileName) / LoadFromCSVData(FileName, TEncoding)
  • Grid.LoadFromCSVStreamData(Stream) / LoadFromCSVStreamData(Stream, TEncoding)
  • Grid.SaveToCSVData(FileName) / SaveToCSVData(FileName, TEncoding)
  • Grid.SaveToCSVStreamData(Stream) / SaveToCSVStreamData(Stream, TEncoding)
  • Grid.Options.IO.StartColumn / StartRow / MaxRows
  • Grid.Options.IO.Delimiter — #0 = auto-detect; set to ',', ';', #9, etc. to force
  • Grid.Options.IO.AlwaysQuotes / QuoteEmptyCells — quoting behaviour
  • Grid.Options.IO.TrimSpaces — strip whitespace on import
  • Grid.Options.IO.OpenAfterCreation — open in default app after save
  • Grid.Columns[i].Formatting — type and format string for parsing/display
  • OnLoadCellData — transform a cell value as it is read from the file.
  • OnSaveCellData — override a cell value as it is written to the file.

See also