如何在PB中选择目录

声明API函数：
Function unsignedlong SHGetPathFromIDListA( unsignedlong pidl, ref string pszPath) Library 'shell32'
Function unsignedlong SHBrowseForFolderA( browseinfo lpbrowseinfo ) Library 'shell32'
Subroutine CoTaskMemFree(ulong idlist) Library 'ole32'

建立函数：
string browseforfolder(window awi_parent,string(as_caption)
函数内容：
browseinfo lstr_bi
itemidlist lstr_idl
unsignedlong ll_pidl
unsignedlong ll_r
Integer li_pos
String ls_Path
unsignedlong ll_Null

SetNull( ll_Null )

unsignedLong BIF_RETURNONLYFSDIRS = 1
lstr_bi.hOwner = Handle( awi_Parent )
lstr_bi.pidlRoot = 0
lstr_bi.lpszTitle = as_caption
lstr_bi.ulFlags = bif_ReturnOnlyFSDirs
lstr_bi.pszDisplayName = Space( 255 )
lstr_bi.lpfn = ll_Null

ll_pidl = SHBrowseForFolderA( lstr_bi )

ls_Path = Space( 255 )
ll_R = SHGetPathFromIDListA( ll_pidl, ls_Path )

CoTaskMemFree( ll_pidl )

RETURN ls_Path

其他地方引用的方法：
String ls_dir
ls_dir = BrowseForFolder( parent, '选择目录' ) //parent为按钮所在的窗口
//ls_dir为选择的目录。