delphi如何读写二进制文件

delphi怎么读写二进制文件？
代码如下：
var
    iFileHandle:   Integer;
    iFileLength:   Integer;
    iBytesRead:   Integer;
    Buffer:   PChar;
    i:   Integer;
    str:String;

    begin
              iFileHandle   :=   FileOpen( 'C:\test.t ',   fmOpenRead);
            iFileLength   :=   FileSeek(iFileHandle,0,2);
            FileSeek(iFileHandle,0,0);
            Buffer   :=   PChar(AllocMem(iFileLength   +   1));
            iBytesRead   :=   FileRead(iFileHandle,   Buffer,   iFileLength);
            FileClose(iFileHandle);
            for   i   :=   0   to   iBytesRead-1   do
            begin
                str   :=   str   +   IntToStr(Integer(Buffer[i]));
            end;

end;
其他试了tmemorystream啥的，总也不对！一个一个读可以，整个读总不行，是不是没设成二进制模式，遇到结束符了？

[解决办法]
http://www.moon-soft.com/program/bbs/readelite1751.htm
[解决办法]
var
iFileHandle: Integer;
iFileLength: Integer;
iBytesRead: Integer;
Buffer: array of Byte;
i: Integer;
str:String;
begin
iFileHandle := FileOpen( 'C:\test.t ', fmOpenRead);
iFileLength := FileSeek(iFileHandle, 0, 2);
FileSeek(iFileHandle, 0, 0);
SetLength(Buffer, iFileLength);
iBytesRead := FileRead(iFileHandle, Buffer[0], iFileLength);
FileClose(iFileHandle);
str := ' ';
for i := 0 to iBytesRead - 1 do
begin
str := str + IntToStr(Buffer[i]);
end;
ShowMessage(str);
Buffer := nil;
end;

[解决办法]
iBytesRead := FileRead(iFileHandle, Buffer, iFileLength); <-- delphi 中用Buffer参数，不能直接传递指针，而是需要传递指针所指的位置。所以改成这样吧：

iBytesRead := FileRead(iFileHandle, Buffer^, iFileLength);