The Relationship Between Messages and Events
Now that you know all the ins and outs of messages, recall that this chapter began by stating that VCL encapsulates many Windows messages in its event system. Delphi's event system is designed to be an easy interface into Windows messages. Many VCL events have a direct correlation with WM_XXX Windows messages. Table 3.3 shows some common VCL events and the Windows message responsible for each event.
| VCL Event | Windows Message |
|---|---|
| OnActivate | wm_Activate |
| OnClick | wm_XButtonDown |
| OnCreate | wm_Create |
| OnDblClick | wm_XButtonDblClick |
| OnKeyDown | wm_KeyDown |
| OnKeyPress | wm_Char |
| OnKeyUp | wm_KeyUp |
| OnPaint | WM_PAINT |
| OnResize | wm_Size |
| OnTimer | wm_Timer |
Table 3.3 is a good ...
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