# 转换 Byte 数组到 ... - 回复 "高群" 的问题

{转换 TBytes 到 Integer}
procedure TForm1.Button1Click(Sender: TObject);
var
bs: TBytes; {TBytes 就是 Byte 的动态数组}
i: Integer;
begin
{它应该和 Integer 一样大小才适合转换}
SetLength(bs, 4);
bs[0] := $10; bs[1] :=$27;
bs[2] := 0;
bs[3] := 0;

{因为 TBytes 是动态数组, 所以它的变量 bs 是个指针; 所以先转换到 PInteger}
i := PInteger(bs)^;
ShowMessage(IntToStr(i)); {10000}
end;

{从 Bytes 静态数组到 Integer 的转换会方便些}
procedure TForm1.Button2Click(Sender: TObject);
var
bs: array[0..3] of Byte;
i: Integer;
begin
bs[0] := $10; bs[1] :=$27;
bs[2] := 0;
bs[3] := 0;

i := Integer(bs);
ShowMessage(IntToStr(i)); {10000}
end;

{转换到自定义的结构}
procedure TForm1.Button3Click(Sender: TObject);
type
TData = packed record
a: Integer;
b: Word;
end;
var
bs: array[0..5] of Byte; {这个数组应该和结构大小一直}
data: TData;
begin
FillChar(bs, Length(bs), 0);
bs[0] := $10; bs[1] :=$27;

data := TData(bs);
ShowMessage(IntToStr(data.a)); {10000}
end;

{转换给自定义结构的一个成员}
procedure TForm1.Button4Click(Sender: TObject);
type
TData = packed record
a: Integer;
b: Word;
end;
var
bs: array[0..3] of Byte;
data: TData;
begin
FillChar(bs, Length(bs), 0);
bs[0] := $10; bs[1] :=$27;

data.a := Integer(bs);
ShowMessage(IntToStr(data.a)); {10000}
end;


posted on 2009-03-21 22:16  万一  阅读(...)  评论(...编辑  收藏