php method to convert colors to hexadecimal: first create a PHP sample file; then use the "function RGBToHex($rgb){...}" method to convert RGB colors to hexadecimal colors That’s it.
The operating environment of this article: Windows7 system, PHP7.1 version, DELL G3 computer
Hexadecimal color and How to convert RGB color values to each other
The hexadecimal color value is usually expressed as #FFFFFF, and currently it is also reduced to #FFF, provided that the two digits must be the same, such as #FEFEFE. It cannot be reduced. The RGB color format is composed of three groups of numbers from 0 to 255, which represent the color values of red, green, and blue respectively.
So, converting hexadecimal to RGB color values is actually to convert the two digits after the # sign into decimal as one unit.
The code is as follows:
/** * 将16进制颜色转换为RGB * author www.jb51.net */ function hex2rgb($hexColor){ $color=str_replace('#','',$hexColor); if (strlen($color)> 3){ $rgb=array( 'r'=>hexdec(substr($color,0,2)), 'g'=>hexdec(substr($color,2,2)), 'b'=>hexdec(substr($color,4,2)) ); }else{ $r=substr($color,0,1). substr($color,0,1); $g=substr($color,1,1). substr($color,1,1); $b=substr($color,2,1). substr($color,2,1); $rgb=array( 'r'=>hexdec($r), 'g'=>hexdec($g), 'b'=>hexdec($b) ); } return $rgb; }
Another way of writing
/** * 十六进制转RGB * @param string $color 16进制颜色值 * @return array */ public static function hex2rgb($color) { $hexColor = str_replace('#', '', $color); $lens = strlen($hexColor); if ($lens != 3 && $lens != 6) { return false; } $newcolor = ''; if ($lens == 3) { for ($i = 0; $i < $lens; $i++) { $newcolor .= $hexColor[$i] . $hexColor[$i]; } } else { $newcolor = $hexColor; } $hex = str_split($newcolor, 2); $rgb = []; foreach ($hex as $key => $vls) { $rgb[] = hexdec($vls); } return $rgb; }
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RGB color and hexadecimal color conversion
/** * RGB转 十六进制 * @param $rgb RGB颜色的字符串 如:rgb(255,255,255); * @return string 十六进制颜色值 如:#FFFFFF */ function RGBToHex($rgb){ $regexp = "/^rgb\(([0-9]{0,3})\,\s*([0-9]{0,3})\,\s*([0-9]{0,3})\)/"; $re = preg_match($regexp, $rgb, $match); $re = array_shift($match); $hexColor = "#"; $hex = array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'); for ($i = 0; $i < 3; $i++) { $r = null; $c = $match[$i]; $hexAr = array(); while ($c > 16) { $r = $c % 16; $c = ($c / 16) >> 0; array_push($hexAr, $hex[$r]); } array_push($hexAr, $hex[$c]); $ret = array_reverse($hexAr); $item = implode('', $ret); $item = str_pad($item, 2, '0', STR_PAD_LEFT); $hexColor .= $item; } return $hexColor; } /** * 十六进制 转 RGB */ function hex2rgb($hexColor) { $color = str_replace('#', '', $hexColor); if (strlen($color) > 3) { $rgb = array( 'r' => hexdec(substr($color, 0, 2)), 'g' => hexdec(substr($color, 2, 2)), 'b' => hexdec(substr($color, 4, 2)) ); } else { $color = $hexColor; $r = substr($color, 0, 1) . substr($color, 0, 1); $g = substr($color, 1, 1) . substr($color, 1, 1); $b = substr($color, 2, 1) . substr($color, 2, 1); $rgb = array( 'r' => hexdec($r), 'g' => hexdec($g), 'b' => hexdec($b) ); } return $rgb; }
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