Delphi中Byte与其它数据类型之间的转换

快来打我* 2021-11-22 23:10 918阅读 0赞

//1.
    procedure TForm1.FormCreate(Sender: TObject);
    type
        TByteArr = array [0..1] of Byte;
        PByteArr = ^TByteArr;
    var
      Bytes: TBytes;
      buf,buf2: TByteArr;
      cmd,n_10: string;
      Len: Integer;
      c: char;
      n_int:ushort;
      w:Word;  {Ushort : word}
    
    begin
        cmd:= 'F';
        n_int:= 513;                 {0000 0010 0000 0001 }
    
        c:= '1';
        Bytes := TEncoding.ASCII.GetBytes(cmd);  {将string类型中的字符转ASCII}
        Len := Length(Bytes);
        cmd:= IntToHex(n_int,2);       {将int类型转出16进制字符串}
        {1}
        Move(n_int,buf,SizeOf(n_int));  {将int 转 Buff}
        {2}
        buf2:= PByteArr(@n_int)^;
    end;
    
    //2.
    procedure TForm1.RzButton1Click(Sender: TObject);
    var
      buf: array[0..1] of byte;
      bus: array[0..3] of byte;
      si:SmallInt ;
      i:Integer ;
      w1,w2:Word;    //two bytes represent a word, not an integer
    begin                       {定义Byte，并写入数据}
      buf[0] := $01;
      buf[1] := $02;          {0000 0010 0000 0001 }
      bus[0] := $00;
      bus[1] := $01;
      bus[2] := $02;
      bus[3] := $03;
    {1}
      Move(buf,si,SizeOf(SmallInt) );
      ShowMessage(IntToStr(si));
    {2}
      WordRec(w1).Lo:= buf[0];
      WordRec(w1).Hi:= buf[1];
      w2:= PWORD(@buf)^;
    {3}
      Move(bus,i,SizeOf(Integer) );
      ShowMessage(IntToStr(i));
    end;
    
    //3.
    procedure TForm1.RzButton2Click(Sender: TObject);
    var
      a: array[0..7] of Byte;
      d1, d2: Double;
    begin
      d1 := 123.456;
      fillchar(a, 8, 0);     {fillchar}
      Move(d1, a, 8);
      Move(a, d2, 8);
      ShowMessage(FloatToStr(d2));
    end;