请教一个DLL兼容性的问题？？？ 100分(100分)

我用DELPHI写了一个非常简单的DLL做试验，让VB调用，<br>发现用除了PCHAR类型以外得所有类型做为传递参数在VB就能调用成功，可是一用PCHAR,<br>VB调用的时候老是关闭性错误！<br>请那位高人指点迷经(函数调用一定得有字符参数)<br>程序如下：<br>Delphi DLL<br>**********************************<br>library Project1;<br>uses<br>&nbsp; SysUtils,<br>&nbsp; Classes;<br><br>{$R *.res}<br>function robtest(VAR bufchar):integer;stdcall;<br>&nbsp; begin<br>&nbsp; &nbsp;buf:='rob';<br>&nbsp; &nbsp;result:=2003;<br>&nbsp; end;<br><br>exports<br>&nbsp; &nbsp;robtest;<br>begin<br>end.<br>*************************************************<br>VB 调用程序<br>Private Declare Function robtest Lib "c:/windows/desktop/dll/test/Project1.dll" (ByVal buf As String) As Long<br><br>Private Sub Command1_Click()<br>Dim a As Integer<br>Dim bb As String <br>a = robtest(bb)<br>Text1.Text = Text1.Text + bb + ";" + Str(a)<br>End Sub<br>**************************************************<br><br>

临时变量作用域的问题，函数执行完就被释放了

问题自己已经解决了<br>是DELPHI中function里用Var 声明的参数，在VB调用里不能加Byval<br>delphi里给PCHAR参数赋值时用，用个string类型变量倒一下<br>修改后<br>elphi DLL<br>**********************************<br>library Project1;<br>uses<br>&nbsp; SysUtils,<br>&nbsp; Classes;<br><br>{$R *.res}<br>function robtest(VAR bufchar):integer;stdcall;<br>var<br>tempL:string;<br>begin<br>&nbsp; &nbsp;temp:='rob';<br>&nbsp; &nbsp;buf:=pchar(temp);<br>&nbsp; &nbsp;result:=2003;<br>end;<br><br>exports<br>&nbsp; &nbsp;robtest;<br>begin<br>end.<br>*************************************************<br>VB 调用程序<br>Private Declare Function robtest Lib "c:/windows/desktop/dll/test/Project1.dll" (buf As String) As Long<br><br>Private Sub Command1_Click()<br>Dim a As Integer<br>Dim bb As String <br>a = robtest(bb)<br>Text1.Text = Text1.Text + bb + ";" + Str(a)<br>End Sub<br>**************************************************<br>

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学习，还不结贴呀。