Question and Answer Database FAQ929C.txt Window Handles and Object Pointers Category :VCL Platform :All Product :C++Builder 1.x Question: I'm calling SendMessage like this: SendMessage(Form1->Edit1, ED_FMTLINES, true, 0); and i'm getting compiler errors. What am I doing wrong? Answer: Most Windows API functions expect to receive as one of their parameters a handle to the window on which they should be operating. The handle is a pointer to a structure in which Windows stores information it needs regarding the window with which it is associated. Statements like Form1->Edit1 represent the _VCL type_ of a control, not the _Windows handle_ of the control. To obtain a handle which can be used in the Windows context, you must query the Handle property of the VCL object you wish to operate on, like so: Form1->Edit1->Handle this will provide Windows with access to the information it needs to perform the desired operation. 7/2/98 10:32:32 AM
Last Modified: 01-SEP-99