10 Practical TAdvSpreadGrid Tips for Faster UI Development

Customize and Extend TAdvSpreadGrid: Best Practices and Examples

Overview

TAdvSpreadGrid (from TMS Software) is a feature-rich VCL grid component for Delphi/C++Builder used to display and edit spreadsheet-like data with extensive customization options. Best practices focus on performance, maintainability, and user experience while examples show common customizations and extensions.

Best practices

• Performance:

  • Use virtual data mode (store data externally and supply on demand) for very large datasets.
  • Avoid heavy operations in OnGetCell and OnDrawCell; cache computed values and styles.
  • Turn off unnecessary repainting (BeginUpdate/EndUpdate) during batch changes.

• Separation of concerns:

  • Keep data logic separate from UI: use a data layer (datasets, in-memory lists) and bind to the grid.
  • Encapsulate customization code (styling, event handlers) in dedicated methods or components.

• Styling and theming:

  • Use named cell styles for reuse across columns/rows.
  • Apply conditional formatting via events or style assignment, not per-cell manual painting.
  • Keep color/ font choices consistent with application theme; provide a high-contrast option.

• Editing and validation:

  • Use built-in cell editors (combobox, checkbox, datepicker) where possible.
  • Validate edits in OnValidateCell or dataset events; provide clear inline error feedback.
  • Support undo/redo if users perform complex edits.

• Accessibility and UX:

  • Ensure keyboard navigation, focus cues, and mnemonic support work.
  • Provide context menus and useful right-click actions.
  • Make column resizing, reordering, freezing, and filtering discoverable (toolbar/icons).

• Maintainability:

  • Document custom cell types and event behaviors.
  • Use descriptive names for styles and custom renderers.
  • Write unit tests for data-layer behavior that drives the grid.

Common customizations (with concise examples)

• Custom cell renderer (owner-draw style):

  • Use the OnDrawCell/OnGetCellColor events to draw icons, progress bars, or combine text+image.
  • Cache images in an ImageList; draw with DrawBitmap for performance.

• Virtual mode (large lists):

  • Set grid to virtual and implement OnGetCellText/OnGetCellValue to supply values from a list or database on demand.
  • Handle sorting by maintaining an index map instead of moving data.

• In-place editors and dropdown lists:

  • Assign column EditorType (ComboBox, DatePicker, UpDown) or create a custom editor component.
  • Populate dropdowns on-demand in OnEditStart to reduce memory use.

• Conditional formatting:

  • In OnGetCellColor or OnGetCellFont, inspect value and apply style names (e.g., “NegativeValue”, “HighPriority”).
  • For complex rules, evaluate in background and store style indices for fast lookup.

• Merged cells and fixed headers:

  • Use MergeRange properties for visual grouping; ensure keyboard navigation respects merged areas.
  • Keep header rows fixed and implement sticky column headers for large vertical scrolls.

• Sorting, grouping, and filtering:

  • Implement custom sorting handlers that manipulate a view index array.
  • For grouping, maintain a hierarchical view and custom draw group headers with expand/collapse controls.
  • Provide a filter row using in-place editors in a top row and apply filters to the underlying dataset.

• Export/Import (Excel/CSV):

  • Use built-in export helpers when available; for CSV stream rows directly from data source to avoid double memory copies.
  • Preserve styles by exporting to formats that support styling (XLSX) and map grid styles to format styles.

Short code sketch (Delphi-style pseudocode)

Code
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procedure TForm1.AdvSpreadGridGetCellText(Sender: TObject; ACol, ARow: Integer; var Value: string); beginValue := MyDataList[RowIndexMap[ARow]].DisplayValue; end;

 
procedure TForm1.AdvSpreadGridDrawCell(Sender: TObject; ACol, ARow: Integer; Rect: TRect; State: TGridDrawState); begin   if IsPriorityRow(ARow) then
 
Grid.Canvas.Font.Style := [fsBold]; 
// draw icon from imagelist   ImageList.Draw(Grid.Canvas, Rect.Left + 2, Rect.Top + 2, IconIndexForCell(ACol, ARow)); end; 

Example scenarios

Dashboard: show sparklines and progress bars in cells; use virtual mode for streaming metrics.
Data entry form: lock computed columns, provide dropdown editors, validate on change, and support undo.
Reporting tool: allow users to group rows, freeze panes, and export styled XLSX reports.

Troubleshooting tips

Flicker or slow redraws: wrap changes in BeginUpdate/EndUpdate and avoid expensive operations in paint events.
Editor focus issues: ensure EditMode is set correctly and manage OnEditStart/OnEditDone events.
Sorting mismatches: sort the underlying data or maintain a consistent index map.

If you want, I can provide a full sample Delphi unit demonstrating virtual mode, custom drawing, editors, and export—state whether you prefer a minimal or complete example.