Handle of a canvas

[sorapan14]

I´m trying to show my graphical representation in a canvas, i´m using delphi, normally works in a new windows this representation. when i pass the handle of this window to the canvas the system works correctly but if i cut the execution of the representation and try to reload the graphics i have some problems with the window class and is imposible to register the handle in this canvas ¿any idea?. Thanks