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<html><head><style><--! A{text-decoration:none}--></style><meta http-equiv=Content-Type content=text/html; charset=gb2312><meta name=GENERATOR content=Microsoft FrontPage 3.0><meta name=Microsoft Border content=none><title>COM/DCOM中如何传递数组</title></head><body style=font-family: 宋体, serif; font-size: 9pt link=#000080 vlink=#000080
alink=#000080><center><span style=font-family: 宋体; font-size: 9pt><b><br>COM/DCOM中如何传递数组</b></span></center><center><span style=font-family: 宋体; font-size: 9pt>西安 &nbsp;&nbsp;&nbsp;&nbsp; <a href=mailto:delphifan@990.net>梁&nbsp; 明</a></span></center><hr><ul> <li><span style=font-family: 宋体; font-size: 9pt>COM/DCOM中如何传递数组: </span><p><span
 style=font-family: 宋体; font-size: 9pt>&nbsp;&nbsp;&nbsp; 因为COM/DCOM对象都不在Client程序运行的内存空间(内进程COM对象除外,即便如此,为了统一接口,内进程的COM也不得传递指针),而且在Win32中所有的程序都有自己独立的2GB的内存空间,程序与程序之间传递指针(内存地址)是毫无意义的,而数组、字符串等大量的数据在程序中都是分配一定的内存空间,然后用指针加内存偏移量来存取数据的,这时,如何在COM/DCOM对象中如何传递呢? <br> &nbsp;&nbsp;&nbsp; 在Win32中引入了一新变量Variant,可以通过Variant传递数组。具体的实现方法,用Delphi实现为: </span></p> <p><span style=font-family: 宋体; font-size: 9pt>&nbsp;&nbsp;&nbsp; Server(COM/DCOM程序)端: <br> &nbsp;&nbsp;&nbsp; procedure TTestDCOM.Send4(Size: Integer; D1: OleVariant); <br> &nbsp;&nbsp;&nbsp; type <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; TData=array [0..999] of Byte; <br> &nbsp;&nbsp;&nbsp; Var <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Data:TData; <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; i:Integer; <br> &nbsp;&nbsp;&nbsp; begin <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; for i:=0 to Size-1 do begin <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Data[i]:=D1[i]; <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; end; <br> &nbsp;&nbsp;&nbsp; end; </span></p> <p><span style=font-family: 宋体; font-size: 9pt>&nbsp; <br> &nbsp; Cleint端: </span></p> <p><span style=font-family: 宋体; font-size: 9pt>&nbsp;&nbsp;&nbsp; Var <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; D1:OleVariant; <br> &nbsp;&nbsp;&nbsp; begin <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; D1:=VarArrayCreate([0,99],varByte); </span></p> <p><span style=font-family: 宋体; font-size: 9pt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; { <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; D1[1]:=45; <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ....&nbsp; //将值存入D1中 </span></p> <p><span style=font-family: 宋体; font-size: 9pt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; } <br> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; S.Send4(99,D1);&nbsp; //S是TestDCOM对象 <br> &nbsp;&nbsp;&nbsp; end; <br> &nbsp; <br> &nbsp; <br> &nbsp; 本文作者:傅贵,最后修改日期:1998.1.16</span></p> <p><span style=font-family: 宋体; font-size: 9pt> </span></p> </li></ul><ul> <li><span style=font-family: 宋体; font-size: 9pt>版主:梁明<br> 日期:1999-04-01<br> E-mail:<a href=mailto:delphifan@990.net>delphifan@990.net</a></span></li></ul><hr></body></html>

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