OnDrawCell
February, 2013
TOPIC
One of the advantages of using modern development environments such as Delphi is to hide the complexities of displaying controls on a form. Simply place a button or a grid or a label on your form and it looks and behaves like a button or a grid or a label should without any special work. But what if you need to do something that is not covered by the standard set of properties? What if you need to place a bitmap or draw a line or join some cells in a way not supported natively by the control? In some cases, third-party libraries provide just what you need, but in others, you have to do it yourself.
Fortunately, the Windows controls on the Delphi tool palette are simply wrappers around Windows objects and the API to control them is easily accessible.
This is nothing new. Since Delphi 1, developers have been able to explicitly dictate every aspect of a control’s look and feel if they are willing to dig down just under the surface by setting a property or two and hooking into an event.
Tonight, we’ll show a real-world application that manipulates a StringGrid to combine cells, color them, and fill them with data. We’ll touch on a few other controls as well and explore the technology a bit to help you break through the mysterious barrier of the Canvas and how you can Paint on it!
PRESENTER
David Cornelius has been developing software since the mid-80’s. He is the coordinator of the Oregon Delphi User Group and is a software development manager at Retail Dimensions. You can read more about him and his programming interests on his web site, Cornelius Concepts.