When you ask "How to use an API" you are asking for any API, as there are many such as Win32 API, Directx, Opengl and many others.
Did you mean how to use the Win32 API? Correct?
WM_PASTE is not an API but a build directive that is used as a constant in Win32 API which stands for hexadecimal 0x0302.
And apparently you are using another graphical API, so it is necessary to know the API you are using to know if it is possible to do this only with the API you are using. If you really need to use the Win32 API you will need to have access to the HWND (Handle Window) of the Tcombobox control which is the controller of the control, and access to the message loop of the program.
What you’ve already done?
– Maicon Carraro
declared windows. h and tried to use some functions windows Procedure, but did not compile anything. made some statements in . h of my form as I had searched, but, n had result. I stopped there and thought: I’m doing everything wrong.
– Grégori Sória
Direct response: Read the relevant API documentation.
– Ericson Willians