← Back to Index

TFlexFMXAdvancedSignatureCapture

Touch-enabled signature capture control for collecting digital signatures with smooth drawing.

Key Properties

PenColor: TAlphaColor
Signature ink color.

PenWidth: Single
Signature line thickness.

BackgroundColor: TAlphaColor
Canvas background color.

ShowBaseline: Boolean
Display a horizontal baseline for signature.

BaselineText: string
Text to display below baseline (e.g., "Sign here").

Smoothing: Boolean
Enable stroke smoothing for natural appearance.

SignatureBitmap: TBitmap
Captured signature as bitmap image.

IsEmpty: Boolean (read-only)
True if no signature has been drawn.

MinStrokeLength: Single
Minimum stroke length to count as valid signature.

Usage Examples

Basic Signature Capture

SignatureCapture1.PenColor := TAlphaColors.Blue;
SignatureCapture1.PenWidth := 2;
SignatureCapture1.ShowBaseline := True;
SignatureCapture1.BaselineText := 'Sign above this line';
SignatureCapture1.Clear;

Save Signature

if not SignatureCapture1.IsEmpty then
begin
  SignatureCapture1.SignatureBitmap.SaveToFile('signature.png');
  ShowMessage('Signature saved');
end
else
  ShowMessage('Please sign first');

Load Existing Signature

var
  Bmp: TBitmap;
begin
  Bmp := TBitmap.Create;
  try
    Bmp.LoadFromFile('signature.png');
    SignatureCapture1.LoadFromBitmap(Bmp);
  finally
    Bmp.Free;
  end;
end;

Validation

procedure ValidateSignature;
begin
  if SignatureCapture1.IsEmpty then
  begin
    ShowMessage('Signature required');
    Exit;
  end;
  
  // Convert to base64 for storage
  var Base64 := BitmapToBase64(SignatureCapture1.SignatureBitmap);
  SaveSignatureToDatabase(Base64);
end;

Methods

Clear - Erase all signature strokes
LoadFromBitmap(Bitmap) - Load signature from bitmap
SaveToFile(FileName) - Save signature as image
GetAsBase64 - Get signature as Base64 string

Events

OnDrawStart - User begins drawing
OnDrawing - User is drawing (mouse/touch move)
OnDrawEnd - User finishes stroke
OnClear - Signature cleared

Notes

Optimized for touch input on mobile devices
Smoothing algorithm produces natural-looking signatures
Works with mouse, touch, and stylus input
Signature bitmap is transparent by default
Consider adding Clear and Save buttons for user convenience
Use validation to ensure signature is not empty before submission

← Back to Index