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rikhong
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为什么我VB调用DELPHI做的DLL，传过去的参数都是乱吗？具体看以下代码
我用参数返回的方式返回一串PCHAR字符，在DELPHI下很正常，但VB连传过去的参数都变成乱码
DELPHI DLL：
procedure SetGunState(Despensor_no
char;Despensor_statechar;protocolchar;var ResultCmdchar);stdcall;
var StrCmd:string;
value:integer;
begin
SHOWMESSAGE(Despensor_no+' '+Despensor_state+' '+Despensor_state); //VB下到这一句发现所有参数都是乱码
value:=StrToInt(Despensor_no);
if protocol = protocol_HS then
begin
StrCmd:=#$41#$42#$43#$61#$62;
end;
if protocol = protocol_HS1 then
begin
StrCmd:=(#$9B+chr(value)+#$02#$A2);
end;
if protocol = protocol_HS2 then
begin
StrCmd:=(#$9B+chr(value)+#$02#$A2);
end;
ResultCmd:=pchar(StrCmd);
ShowMessage(ResultCmd+StrCmd)
end;
VB 调用代码：
Public Declare Sub SetGunState Lib "C:/HScom.dll" (Despensor_no As String, Despensor_state As String, protocol As String, ByRef CMD As String)
Private Sub Command1_Click()
Dim s As String
s = Space(26)
Module1.SetGunState "2", "1", "AA", s
Text1.Text = s
' Module1.Gets
End Sub
我用参数返回的方式返回一串PCHAR字符，在DELPHI下很正常，但VB连传过去的参数都变成乱码
DELPHI DLL：
procedure SetGunState(Despensor_no
char;Despensor_statechar;protocolchar;var ResultCmdchar);stdcall;var StrCmd:string;
value:integer;
begin
SHOWMESSAGE(Despensor_no+' '+Despensor_state+' '+Despensor_state); //VB下到这一句发现所有参数都是乱码
value:=StrToInt(Despensor_no);
if protocol = protocol_HS then
begin
StrCmd:=#$41#$42#$43#$61#$62;
end;
if protocol = protocol_HS1 then
begin
StrCmd:=(#$9B+chr(value)+#$02#$A2);
end;
if protocol = protocol_HS2 then
begin
StrCmd:=(#$9B+chr(value)+#$02#$A2);
end;
ResultCmd:=pchar(StrCmd);
ShowMessage(ResultCmd+StrCmd)
end;
VB 调用代码：
Public Declare Sub SetGunState Lib "C:/HScom.dll" (Despensor_no As String, Despensor_state As String, protocol As String, ByRef CMD As String)
Private Sub Command1_Click()
Dim s As String
s = Space(26)
Module1.SetGunState "2", "1", "AA", s
Text1.Text = s
' Module1.Gets
End Sub
]
!]注意VB存在值传递和引用传递,请使用值传递.