记录的问题？(100分)

M

mao

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GUEST, unregistred user!

• 2002-10-16

• #1

问题是：程序中定义了这么一个记录
Tusrdata= record
num:integer;
inf:array[0..1024] of char
end;

tSocketData=Record
msgCode: word;
msgLen :word;
case integer of
0: (usrdata:Tusrdata);
1: (order:integer);
end;
pSocketdata= ^TSocketdata;

procedure CreateSocket(var sockdataSocketdata);
var
lbuf:array[0..100] of char;
i:integer;
begin
for i；=0 to 99 do
lbuf:='a';
sockdata^.msgcode:=1;
sockdata^.msglen:=104;
sockdata^.usrdata.num:=1;
strplcopy(sockdata^.usrdata.inf,lbuf,100);
//这句话出错，即使是采用for循环赋值也错，报告是 内存访问非法。
end;

 

S

Sachow

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2002-10-16

• #2

procedure CreateSocket(var sockdata: TSocketdata);
var
lbuf:array[0..100] of char;
i:integer;
begin
for i:=0 to 99 do
lbuf:='a';
sockdata.msgcode:=1;
sockdata.msglen:=104;
sockdata.usrdata.num:=1;
strplcopy(sockdata.usrdata.inf,lbuf,100);
end;

 

J

jsxjd

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2002-10-16

• #3

不需要 ^

 

M

mao

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2002-10-17

• #4

多准备给分了，上机试验了一把，去掉^还是不行。

 

C

creation-zy

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2002-10-17

• #5

function StrPLCopy(Dest: PChar
const Source: string
MaxLen: Cardinal): PChar;

sockdata是指针，当然不能把^去掉。您的代码我试验没有任何问题：

procedure TForm1.Button1Click(Sender: TObject);
var
aSocketData;
begin
New(a);
CreateSocket(a);
Caption:=IntToStr(a^.msgLen);
end;

还有，鉴于CreateSocket过程没有改变指针，而只是改变了指针所指向的内存区域的值，
可以声明为： procedure CreateSocket(sockdata: TSocketdata);

 

M

mao

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2002-12-02

• #6

算了，结账喽