Declaration ​
pascal
procedure BeginMeasuring(const Callback: TAreaChangedEvent);Parameters ​
| Parameter | Type | Description |
|---|---|---|
Callback | TAreaChangedEvent | Callback procedure invoked when measuring ends with the accumulated changed region rectangle. |
Description ​
BeginMeasuring puts the bitmap into measuring mode. Subsequent drawing operations will not immediately fire area change events; instead, the modified rectangle areas are tracked and combined into a single bounding rectangle until EndMeasuring is called.
Example ​
pascal
Bitmap.BeginMeasuring(OnAreaMeasured);
try
Bitmap.Line(0, 0, 100, 100, clRed32);
Bitmap.FillRect(20, 20, 80, 80, clBlue32);
finally
Bitmap.EndMeasuring;
end;