By default, the TProgressBar control is used to provide visual feedback about the progress of a procedure within an application. Programmatically, a developer can set Min and Max properties to specify the lower and the upper limit of the range of possible positions. The Position property (or the Step, StepBy methods) is then used to set the current position of the progress bar.
If you want to enable the users of you application to set the position of the progress bar visually, using mouse, you can use the next trick:
//ProgressBar1 OnMouseMove
procedure TForm1.ProgressBar1MouseMove(
Sender: TObject;
Shift: TShiftState;
X, Y: Integer) ;
var
newPosition : integer;
begin
if ssShift in Shift then
begin
ProgressBar1.Cursor := crHSplit;
newPosition := Round(x * ProgressBar1.Max / ProgressBar1.ClientWidth) ;
ProgressBar1.Position := newPosition;
end
else
begin
ProgressBar1.Cursor := crDefault;
end;
end;
The OnMouseMove event for the TProgressBar component named ProgressBar1 is handled, when the mouse is over the ProgressBar control, and the Shift key is pressed, a user can dynamically change the value of the Position property.
Note: the code above assumes that "pbHorizontal" is set for the Orientation property of the ProgressBar - the "X" parameter is used to calculate the new Position value. If "pbVertical" is specified, the "Y" parameter should be used.
Delphi tips navigator:
» How to remeber Delphi form controls position and size
« UDP Makes a Difference (UDP vs. TCP)
