php生成条形码的图片的实例详解

class testinfo{  function UPCAbarcode($code) {    $trans_code = $code;    $lw = 2.2; $hi = 40;    $Lencode = array('0001101','0011001','0010011','0111101','0100011',        '0110001','0101111','0111011','0110111','0001011');    $Rencode = array('1110010','1100110','1101100','1000010','1011100',        '1001110','1010000','1000100','1001000','1110100');    $ends = '101'; $center = '01010';    /* Compute the EAN-13 Checksum digit */    $ncode = '0'.$code;    $even = 0; $odd = 0;    for ($x=0;$x<12;$x++) {      if ($x % 2) {        $odd += $ncode[$x];      } else { $even += $ncode[$x];      }    }    $code.=(10 - (($odd * 3 + $even) % 10)) % 10;    /* Create the bar encoding using a binary string */    $bars=$ends;    $bars.=$Lencode[$code[0]];        for($x=1;$x<6;$x++) {      $bars.=$Lencode[$code[$x]];    }    $bars.=$center;    for($x=6;$x<12;$x++) {      $bars.=$Rencode[$code[$x]];    }    $bars.=$ends;    /* Generate the Barcode Image */    $img = ImageCreate($lw*75+30,$hi-3);  // 95    $fg = ImageColorAllocate($img, 0, 0, 0);    $bg = ImageColorAllocate($img, 255, 255, 255);    ImageFilledRectangle($img, 0, 0, $lw*75+30, $hi+30, $bg);    $shift=10;    for ($x=0;$x<strlen($bars);$x++) {      if (($x<0) || ($x>=45 && $x<46) || ($x >=85)) {        $sh=10;      } else { $sh=0;      }      if ($bars[$x] == '1') {        $color = $fg;      } else { $color = $bg;      }      ImageFilledRectangle($img, ($x*$lw)+15,5,($x+1)*$lw+14,$hi+5+$sh,$color);    }    /* Add the Human Readable Label */    ImageString($img,4,5,$hi-5,$code[0],$fg);    for ($x=0;$x<5;$x++) {      ImageString($img,5,$lw*(13+$x*6)+15,$hi+5,$code[$x+1],$fg);      ImageString($img,5,$lw*(53+$x*6)+15,$hi+5,$code[$x+6],$fg);    }    ImageString($img,4,$lw*95-7,$hi,$code[11],$fg);    /* Output the Header and Content. */    header("Content-Type: image/png");    ImagePNG($img);  }//}echo UPCAbarcode('201212070099');