sql-server - 如何从表示为整数的颜色中输出 RGB 值？

Question

在SQL Server 2012中，您如何将由int（存储为 0xBBGGRR）表示的颜色转换为格式为的字符串R=123, G=234, B=12？我们将忽略 alpha 部分。

例如，给定一个整数 value 0xff223344，你会得到R=68, G=51, B=34。

Answer 1

使用按位和 (&) 运算符：

declare @i int
set @i=0xff223344

select 
  'R=' +   cast(@i & 0xFF as varchar(3)) +
  ', G=' + cast((@i & 0xFF00) / 0x100 as varchar(3)) +
  ', B=' + cast((@i & 0xFF0000) / 0x10000 as varchar(3)) 

Answer 2

那么这样的解决方案呢？

declare @i int = 0x223344

select 'R=' + cast (@i % 256 as varchar)
    + ', G=' + cast (@i / 256 % 256 as varchar)
    + ', B=' + cast (@i / 65536 % 256 as varchar)

或者，如果您有一个fffor alpha 通道：

declare @i int = 0xff443322

if @i < 0
    set @i = @i % cast(0x1000000 as int) - cast(0xff000000 as int)

select 'R=' + cast (@i % 256 as varchar)
    + ', G=' + cast (@i / 256 % 256 as varchar)
    + ', B=' + cast (@i / 65536 % 256 as varchar)

Answer 3

Declare @i int
Set @i=0xff223344
select 
  'R=' + Cast(Cast(SubString(CAST(@i as BINARY(4)),4,1) as int) as Varchar(3))
+ ', G=' + Cast(Cast(SubString(CAST(@i as BINARY(4)),3,1) as int) as Varchar(3))
+ ', B=' + Cast(Cast(SubString(CAST(@i as BINARY(4)),2,1) as int) as Varchar(3))