请问:为什么在pb中调用createwindow()函数出错?
声明如下:
FUNCTION ulong CreateWindow(ref string lpClassName,ref string lpWindowName,ulong dwStyle,ulong x,ulong y,ulong nWidth,ulong nHeight,ulong hWndParent,ulong hMenu,ulong hInstance,Any lpParam) LIBRARY "user32.dll"
调用如下:
string classname='appname'
string wintext='hello world'
ulong x_poinster=0,y_poinster=0,instance=1,dwStyle=2, nWidth=550, nHeight=400,hWndParent,hMenu,hInstance=2
long lpParam
long handle
setnull(lpParam)
setnull(hWndParent)
setnull(hMenu)
handle=createwindow(classname,wintext,0,0,0,550,400,hWndParent,hMenu,handle(getApplication()),lpParam)
出错提示:
error calling external fucntion createwindow......
请问原因?