前几篇笔记习练了IIS soapis30配置、VB6 webservice创建、Delphi7和VB6 webservice访问：
VB6 COM webservice发布，VB.NET和Delphi 7 对webservice访问，及MS Soap Toolkit 3.0在IIS上的ISAPI配置_Mongnewer的博客-CSDN博客
本篇笔记重点编写 Delphi7 DLL 对MS soap3 进行封装，让FreeBASIC通过Delphi7的DLL封装，访问IIS上的Webservice。
主要任务是：1. 编写 Delphi7 DLL， 2. 编写FreeBasic调用程序。
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编写 Delphi7 DLL
打开Delphi7 ， File -> New -> others -> DLL wizard
在创建的DLL项目Project2上引入 Microsoft Soap Type Library v3.0(Version 3.0)
在Project2.pas中use引用的 MSSOAPLib30_TLB
编写三个function，一个是初始化dpSoap3Init、一个是dpEchoString、一个是dpAddNumbers，全部程序如下：
library Project2;
uses
Windows,
Messages,
SysUtils,
Variants,
Classes,
StrUtils,
COMobj,
MSSOAPLib30_TLB in 'C:\Program Files (x86)\Borland\Delphi7\Imports\MSSOAPLib30_TLB.pas';
type
TinRecord = record
vi_param1: short;
vi_param2: short;
End;
var
mySoapClient3: OleVariant;
function dpSoap3Init(): integer; stdcall;
begin
try
mySoapClient3:= CreateOleObject('MSSOAP.SoapClient30');
mySoapClient3.mssoapinit('http://192.168.3.113/Soap3DocSamples/DocSample1/Server/TestWEBservice.WSDL', 'TestWEBservice', 'Sample1SoapPort');
Result:= 0;
except
Result:= 1;
end;
end;
function dpEchoString(inChars: pchar): pchar; stdcall;
var
I: integer;
fromFBstring: string;
fromWSDLstring: string;
p: pchar;
begin
fromFBstring:='';
for I:=0 to 255 do
begin
fromFBstring:= fromFBstring + inChars^;
inc(inChars);
end;
fromFBstring:= Trim(fromFBstring);
fromWSDLstring:= mySoapClient3.EchoString(fromFBstring);
p:= pchar(fromWSDLstring);
Result:= p;
end;
function dpAddNumbers(inType: Pointer): smallint;
var
nBlock: TinRecord;
begin
CopyMemory(@nBlock, inType, sizeof(nBlock));
Result:= mySoapClient3.AddNumbers(nBlock.vi_param1, nBlock.vi_param2);
end;
exports
dpSoap3Init,
dpEchoString,
dpAddNumbers;
{$R *.res}
begin
end.写好代码，然后编译生成 Project.DLL，放到FreeBasic项目的Release下(后面会进一步讲到)。
接下来，创建FreeBASIC标准32位x86窗体项目，放上一些控件，并在窗体通用中放入代码 Dim Shared library As Any Ptr， 这个library将作为动态装入Project2.DLL的指针，供整个程序运行期使用。
在窗体Create创建时，动态调入Project2.DLL，这个DLL要放在工程的 Release下面，与工程的exe放在一起。调入Project2.DLL后取得指针 library，利用指针找到 dpSoap3Init 过程入口地址，然后调用它，并在Text1中显示调用结果，为0表示成功，为1表示失败。
Sub Form1_WM_Create(hWndForm As hWnd, UserData As Integer)
library = DyLibLoad("Project2") '就文件名，不能带 .DLL
If (library = 0) Then
AfxMsg "加载DLL失败"
Return
End If
Dim retVal As Integer
Dim FuncSoap As Function() As Integer
FuncSoap = DyLibSymbol(library, "dpSoap3Init")
If (FuncSoap = 0) Then
AfxMsg "无法从开发DLL例题库中检索dpSoap3Init（）函数的地址"
Return
End If
retVal = FuncSoap()
Text1.text = Str(retVal) 'Should be 0 if success
End Sub
当项目运行结束时，释放 Project2.DLL，此时会用到 library 指针。
Function Form1_WM_Close(hWndForm As hWnd) As LResult
DyLibFree(library)
Function = False ' 返回 TRUE 阻止关闭窗口。
End FunctiondpEchoString的实现。找到dpEchoString函数入口，将字符数组的首地址交给它，然后取得返回的字符数组的首地址。依据返回的首地址，变回Project.DLL发送出来的完整字符串。字符数组长度为256，足以满足使用要求。
'===============================================================================================
Dim fHello As Function(ByVal As UByte Ptr) As UByte Ptr
fHello = DyLibSymbol(library, "dpEchoString")
If (fHello = 0) Then
AfxMsg "无法从开发DLL例题库中检索dpEchoString（）函数的地址"
Return
End If
Dim I As Integer
Dim J As UByte Ptr
Dim sTempString As String
Dim sParam(255) As UByte
sTempString = Trim(Text6.text) & " "
memcpy(@sParam(0), StrPtr(sTempString), Len(sTempString))
J= fHello(@sParam(0))
sTempString = ""
For I = 0 To 255
sTempString = sTempString + Chr(*(J+I))
Next I
Text3.text = Trim(sTempString)再看一下Project2.DLL中对应的代码，它接收来自FreeBASIC的指针，变成字符串后发送给MS Soap Toolkit3的SoapClient3实例mySoapClient3，并接收它返回的字符串，其pchar指针返回给FreeBASIC
function dpEchoString(inChars: pchar): pchar; stdcall;
var
I: integer;
fromFBstring: string;
fromWSDLstring: string;
p: pchar;
begin
fromFBstring:='';
for I:=0 to 255 do
begin
fromFBstring:= fromFBstring + inChars^;
inc(inChars);
end;
fromFBstring:= Trim(fromFBstring);
fromWSDLstring:= mySoapClient3.EchoString(fromFBstring);
p:= pchar(fromWSDLstring);
Result:= p;
end;dpAddNumbers调用使用了变量结构体，取得dpAddNumbers地址后通过它发送结构的地址指针，并在函数返回时获得16位short类型数据值。
Type TParam1
vi_Param1 As Short
vi_Param2 As Short
End Type
Dim fAddNumbers As Function(ByVal As Any Ptr) As Short
fAddNumbers = DyLibSymbol(library, "dpAddNumbers")
If (fAddNumbers = 0) Then
AfxMsg "无法从开发DLL例题库中检索dpAddNumbers（）函数的地址"
Return
End If
Dim Resultval As Short
Dim nParam1 As TParam1
nParam1.vi_Param1 = Val(Text4.text): nParam1.vi_Param2 = Val(Text5.text)
Resultval = fAddNumbers(@nParam1)
Text2.text = Str(Resultval)在Project2.DLL中，也使用了一个定义好的结构体TinRecord。当收到FreeBASIC的结构体指针后，直接将其指向的内容复制给TinRecord结构体实例，然后直接将结构体中的变量发送给mySoapClient3，并将返回的结果返送给FreeBASIC
function dpAddNumbers(inType: Pointer): smallint;
var
nBlock: TinRecord;
begin
CopyMemory(@nBlock, inType, sizeof(nBlock));
Result:= mySoapClient3.AddNumbers(nBlock.vi_param1, nBlock.vi_param2);
end;type
TinRecord = record
vi_param1: short;
vi_param2: short;
End;至此，FreeBASIC通过Delphi7 DLL顺利访问IIS的VB6 webservice
FreeBASIC有个开发中的axSuite是做COM访问的，我还没有试用过。这篇笔记只是针对MS Soap Toolkit 3.0的习练。
