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Show message in OnEnter event

Title: Show message in OnEnter event Question: Do you ever needed to display a message using the OnEnter event? This example shows how to correctly display a message by using the ShowMessage (or an equivalent function) in OnEnter event. Answer: As you have notice, if you call ShowMessage in OnEnter event, mouse will get a bad behavior. Remember that this problem only occurs when the control executes the OnEnter event after you clicked it with the mouse. The trick is by using a user windows message. const UM_SHOWMESSAGE = WM_USER + 256; // Define this procedure to catch our 'ShowMessage' user message procedure UMShowMessage(var Message: TMessage); message UM_SHOWMESSAGE; procedure TForm1.UMShowMessage(var Message: TMessage); begin ShowMessage(PChar(Message.lParam)); end; To activate the message you just need to put this code in OnEnter event: PostMessage(Handle, UM_SHOWMESSAGE, 0, LPARAM(PChar('This is a message')));