vb 调用delphi写的dll

delphi中的DLL中的声明原码如下：
这里声明了输出性参数分别为数字与字符类型
library dll1;
uses
  SysUtils,
  Classes;
{$R *.res}
Function mymax(x, y: Integer; out jj: Integer; out abc: PChar): Integer; stdcall;
begin
  jj := x * y;
  abc := PChar(StrPas(abc) + '这是传出的');
  if X > Y then
    Result := X
  else
    Result := Y;
end;
exports mymax;
begin
end.
vb中的调用程序如下：
Private Declare Function mymax Lib "C:\lx\delphi\lx1\dll1.dll" (ByVal sj1 As Long, ByVal sj2 As Long, ByRef sj3 As Long, ByRef s1 As String) As Long
Private Sub Command1_Click()
 Dim s_t As String
 
  Text3.Text = ""
  sj3_v = 0
  s_t = "测试输入："
  Text3.Text = mymax(Val(Text2.Text), Val(Text1.Text), sj3_v, s_t)
 
  Print (Str(sj3_v) + s_t)
End Sub