DELPHI巨搞笑问题！！！！！！！！！！！！！！！ (100分)

{
Function MyTran(pstrCHAR)CHAR
being
...
end;}


{main}
str:string;
...
str:=MyTran((PCHAR(str));
...

其中在MyTran函数中跟踪返回值正常，返回后常常会在str后面多加一个字符，有誰碰到类似问题没有？

没有，你这个函数有什么意义啊？？？

真是好笑.
str为string类型,却赋值为pchar,要赋值也应该
str:=strpas( MyTran((PCHAR(str)))

才行.

真的很好笑[][][]

Function MyTran(pstrCHAR)CHAR;
begin
Result:=pstr;
end;

procedure TForm1.Button1Click(Sender: TObject);
const
s='ABC';
var
str:string;
begin
ShowMessage(StrPas(MyTran(PChar(s))));
Str:=StrPas(MyTran(PChar(Str)));//和下面的一行分别试
Str:=MyTran(PChar(Str));
ShowMessage(Str);
end;

//没有问题的， 我用上面的三种试的， 没有添加字符

//另:string 和 C的字符串不一样的， PChar的一样都在后面添加一空字符

类型不对了，一个STRING，一个PCHAR，要转换嘛
StrPas(Str: PChar): string;

string 和 pchar是不一样的，前者没有结束标志，由首地址表示长度；
后者有'#0'结束标志

巨搞笑[][][]

str:string;
...
str:=MyTran((PCHAR(str+ #0 ));
~~~~~

补充，以下是delphi官方网站上的提示：
As mentioned earlier, AnsiString types are always null-terminated, so they’re compatible with
null-terminated strings. This makes it easy to call Win32 API functions or other functions
requiring PChar-type strings. All that’s required is that you typecast the string as a PChar.
(Typecasting is explained in more detail in the section “Typecasting and Type Conversion.”)
The following code demonstrates how to call the Win32 GetWindowsDirectory() function,
which accepts a PChar and buffer length as parameters:
var
S: string;
begin
SetLength(S, 256)
// important! get space for string first
// call function, S now holds directory string
GetWindowsDirectory(PChar(S), 256);
end;
After using an AnsiString in which a function or procedure expects a PChar, you must manually
set the length of the string variable to its null-terminated length. The RealizeLength()
function, which also comes from the StrUtils unit, accomplishes that task:
procedure RealizeLength(var S: string);
begin
SetLength(S, StrLen(PChar(S)));
end;
Calling RealizeLength() completes the substitution of a long string for a PChar:
var
S: string;
begin
SetLength(S, 256)
// important! get space for string first
// call function, S now holds directory string
GetWindowsDirectory(PChar(S), 256);
RealizeLength(S)
// set S length to null length
end;

我却不知你们笑什么?

谢谢各位，接受答案了，来者有分