转换 Byte 数组到 ... - 回复

转换 Byte 数组到 ... - 回复 "高群" 的问题

问题来源: https://blog.51cto.com/u_14617575/2748009

{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;