You need to replace the hwnd to point to your added text box (or rich text box):
PHP Code:
Var txtLicense ;textbox handle
Var LicFile ;pointer to the license file in memory
!macro addLicense
${If} $LicFile == ""
ClearErrors
System::Call 'kernel32::CreateFile(t "$PLUGINSDIR\\EULA.rtf", i 0x80000000, i 1, i 0, i 3, i 0, i 0) i .r0'
IfErrors exit
;allocate memory for the file
System::Call 'kernel32::GetFileSize(i r0, i 0) i .r1'
System::Alloc $1
Pop $2
;read the file into memory
System::Call 'kernel32::ReadFile(i r0, i r2, i r1, *i .r3, i 0)'
System::Call 'kernel32::CloseHandle(i r0)'
Push $2 ;Push the License memory location to stack
Pop $LicFile ;Pop the License memory loc to the variable LicFile
${EndIf}
;White background, black text
SetCtlColors $txtLicense 0x000000 0x00FFFFFF
SendMessage $txtLicense ${WM_SETTEXT} 0 $LicFile
exit:
!macroend
Then, deallocate the memory when the installer closes:
PHP Code:
Function .onGUIEnd
System::Free $LicFile ;clear the memory allocated for the license file
FunctionEnd