Declaring API externs with structures

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skidracer
 #1
SuperStrict

Const TH32CS_SNAPPROCESS:Int = 2

Type PROCESSENTRY32

	Field dwSize:Int
	Field cntUsage:Int
	Field th32ProcessID:Int
	Field th32DefaultHeapID:Int
	Field th32ModuleID:Int
	Field cntThreads:Int
	Field th32ParentProcessID:Int
	Field pcPriClassBase:Int
	Field dwFlags:Int
	Field szExeFile:Byte,b1:Byte,b2:Byte,b3:Byte	'4 + 256=260 bytes for path
	Field p0:Long,p1:Long,p2:Long,p3:Long
	Field p4:Long,p5:Long,p6:Long,p7:Long
	Field p8:Long,p9:Long,pa:Long,pb:Long
	Field pc:Long,pd:Long,pe:Long,pf:Long
	Field q0:Long,q1:Long,q2:Long,q3:Long
	Field q4:Long,q5:Long,q6:Long,q7:Long
	Field q8:Long,q9:Long,qa:Long,qb:Long
	Field qc:Long,qd:Long,qe:Long,qf:Long
	Field th32MemoryBase:Int
	Field th32AccessKey:Int
End Type  

Extern "Win32"
	Function WinExec(lpCmdLine:Byte Ptr,nCmdShow:Int)
	Function CreateToolhelp32Snapshot:Int(lFlags:Int, lProcessID:Int)
	Function Process32First(hSnapShot:Int, uProcess:Byte Ptr)
	Function Process32Next(hSnapShot:Int, uProcess:Byte Ptr)
	Function CloseHandle(hPass:Int)
End Extern

Local p:PROCESSENTRY32=New PROCESSENTRY32
p.dwSize=SizeOf(processentry32)
Local h:Int=CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS,0)
process32First(h,p)
DebugLog "szExeFile="+String.FromCString(Varptr p.szExeFile)
While process32Next(h,p)
	DebugLog " szExeFile="+String.FromCString(Varptr p.szExeFile)
Wend


Note the need to declare the arguments in extern functions as type byte ptr to correctly pass the bmx object as a struct.