PHP实现GIF图片验证码

5年以前  |  阅读数:1128 次  |  编程语言:PHP 

这是一个用PHP生成GIF动画来实现动态图片验证码的程序,非常实用,是php用户注册登录界面经常需要用到的验证码程序,有需要GIF动态图片验证码功能的朋友可以收藏一下。
第一步:创建ImageCode.php文件,验证码生成函数代码如下:


    <?php
    /**
     * ImageCode 生成GIF图片验证
     * @param $string 字符串
     * @param $width 宽度
     * @param $height 高度
     * */
    function ImageCode($string = '', $width = 75, $height = 25)
    {
      $authstr = $string ? $string : ((time() % 2 == 0) ? mt_rand(1000, 9999) : mt_rand(10000, 99999));
      $board_width = $width;
      $board_height = $height;
      // 生成一个32帧的GIF动画
      for($i = 0; $i < 32; $i++)
      {
        ob_start();
        $image = imagecreate($board_width, $board_height);
        imagecolorallocate($image, 0,0,0);
        // 设定文字颜色数组
        $colorList[] = ImageColorAllocate($image, 15,73,210);
        $colorList[] = ImageColorAllocate($image, 0,64,0);
        $colorList[] = ImageColorAllocate($image, 0,0,64);
        $colorList[] = ImageColorAllocate($image, 0,128,128);
        $colorList[] = ImageColorAllocate($image, 27,52,47);
        $colorList[] = ImageColorAllocate($image, 51,0,102);
        $colorList[] = ImageColorAllocate($image, 0,0,145);
        $colorList[] = ImageColorAllocate($image, 0,0,113);
        $colorList[] = ImageColorAllocate($image, 0,51,51);
        $colorList[] = ImageColorAllocate($image, 158,180,35);
        $colorList[] = ImageColorAllocate($image, 59,59,59);
        $colorList[] = ImageColorAllocate($image, 0,0,0);
        $colorList[] = ImageColorAllocate($image, 1,128,180);
        $colorList[] = ImageColorAllocate($image, 0,153,51);
        $colorList[] = ImageColorAllocate($image, 60,131,1);
        $colorList[] = ImageColorAllocate($image, 0,0,0);
        $fontcolor = ImageColorAllocate($image, 0,0,0);
        $gray = ImageColorAllocate($image, 245,245,245);    
        $color = imagecolorallocate($image, 255,255,255);
        $color2 = imagecolorallocate($image, 255,0,0);
        imagefill($image, 0, 0, $gray);
        $space = 15;    // 字符间距
        if($i > 0)      // 屏蔽第一帧
        {
          for ($k = 0; $k < strlen($authstr); $k++)
          {
            $colorRandom = mt_rand(0,sizeof($colorList)-1);
            $float_top = rand(0,4);
            $float_left = rand(0,3);
            imagestring($image, 6, $space * $k, $top + $float_top, substr($authstr, $k, 1), $colorList[$colorRandom]);
          }
        }

        for ($k = 0; $k < 20; $k++)
        {
          $colorRandom = mt_rand(0,sizeof($colorList)-1);
          imagesetpixel($image, rand()%70 , rand()%15 , $colorList[$colorRandom]);  
        }
        // 添加干扰线
        for($k = 0; $k < 3; $k++)
        {
          $colorRandom = mt_rand(0, sizeof($colorList)-1);
          // $todrawline = rand(0,1);
          $todrawline = 1;
          if($todrawline)
          {
            imageline($image, mt_rand(0, $board_width), mt_rand(0,$board_height), mt_rand(0,$board_width), mt_rand(0,$board_height), $colorList[$colorRandom]);
          }
          else
          {
            $w = mt_rand(0,$board_width);
            $h = mt_rand(0,$board_width);
            imagearc($image, $board_width - floor($w / 2) , floor($h / 2), $w, $h, rand(90,180), rand(180,270), $colorList[$colorRandom]);
          }
        }
        imagegif($image);
        imagedestroy($image);
        $imagedata[] = ob_get_contents();
        ob_clean(); 
        ++$i; 
      }  
      $gif = new GIFEncoder($imagedata); 
      Header ('Content-type:image/gif'); 
      echo $gif->GetAnimation(); 
    }
    /**
     * GIFEncoder类
     * */
    Class GIFEncoder
    {
      var $GIF = "GIF89a";        /* GIF header 6 bytes    */ 
      var $VER = "GIFEncoder V2.06";    /* Encoder version       */ 
      var $BUF = Array ( ); 
      var $LOP = 0; 
      var $DIS = 2; 
      var $COL = -1; 
      var $IMG = -1; 
      var $ERR = Array ( 
        'ERR00' =>"Does not supported function for only one image!", 
        'ERR01' =>"Source is not a GIF image!", 
        'ERR02' =>"Unintelligible flag ", 
        'ERR03' =>"Could not make animation from animated GIF source", 
      ); 
      function GIFEncoder ($GIF_src, $GIF_dly = 100, $GIF_lop = 0, $GIF_dis = 0, $GIF_red = 0, $GIF_grn = 0, $GIF_blu = 0, $GIF_mod = 'bin' )
      { 
        if (!is_array($GIF_src) && !is_array($GIF_tim))
        { 
          printf ( "%s: %s", $this->VER, $this->ERR['ERR00']); 
          exit( 0 );
        } 
        $this->LOP = ($GIF_lop > -1) ? $GIF_lop : 0;
        $this->DIS = ($GIF_dis > -1) ? (( $GIF_dis < 3 ) ? $GIF_dis : 3) : 2; 

        $this->COL = ($GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1) ? ($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : -1; 
        for ($i = 0, $src_count = count($GIF_src); $i < $src_count; $i++ )

        {
          if (strToLower( $GIF_mod ) == "url")
          { 
            $this->BUF[] = fread (fopen($GIF_src [$i], "rb"), filesize ($GIF_src [$i])); 
          } 
          elseif(strToLower($GIF_mod) == "bin")
          { 

            $this->BUF [ ] = $GIF_src [ $i ]; 
          } 
          else
          { 
            printf("%s: %s ( %s )!", $this->VER, $this->ERR [ 'ERR02' ], $GIF_mod); 

            exit(0); 
          } 
          if (substr($this->BUF[$i], 0, 6) != "GIF87a" && substr($this->BUF [$i], 0, 6) != "GIF89a")

          { 

            printf( "%s: %d %s", $this->VER, $i, $this->ERR ['ERR01']); 

            exit(0); 
          } 
          for ($j = (13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07 ))), $k = TRUE; $k; $j++)
          { 
            switch ($this->BUF [$i]{$j})
            { 
              case "!": 
                if ((substr($this->BUF[$i], ($j + 3), 8)) == "NETSCAPE")
                { 
                    printf( "%s: %s ( %s source )!", $this->VER, $this->ERR ['ERR03'], ($i + 1)); 
                    exit( 0 ); 
                } 
                break; 
                case ";": 
                $k = FALSE; 
                break; 
            } 
          } 
        } 
        GIFEncoder::GIFAddHeader(); 
        for($i = 0, $count_buf = count($this->BUF); $i < $count_buf; $i++)
        { 
          GIFEncoder::GIFAddFrames($i, $GIF_dly[$i]); 
        } 
        GIFEncoder::GIFAddFooter(); 
      } 
      function GIFAddHeader ( )
      { 
        $cmap = 0; 
        if (ord($this->BUF[0]{10}) & 0x80 )
        { 
          $cmap = 3 * ( 2 << ( ord ( $this->BUF [ 0 ]{10} ) & 0x07 )); 

          $this->GIF .= substr ( $this->BUF [ 0 ], 6, 7); 

          $this->GIF .= substr ( $this->BUF [ 0 ], 13, $cmap); 
          $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . GIFEncoder::GIFWord ( $this->LOP ) . "\0"; 
        } 
      } 
      function GIFAddFrames ( $i, $d )
      { 
        $Locals_str = 13 + 3 * (2 <<(ord($this->BUF[$i]{10}) & 0x07)); 
        $Locals_end = strlen($this->BUF[$i]) - $Locals_str - 1; 
        $Locals_tmp = substr ($this->BUF[$i], $Locals_str, $Locals_end); 
        $Global_len = 2 << (ord( $this->BUF [0]{10} ) & 0x07 ); 
        $Locals_len = 2 << (ord( $this->BUF[$i]{10}) & 0x07); 
        $Global_rgb = substr($this->BUF[0], 13, 3 * (2 << ( ord ( $this->BUF[0]{10} ) & 0x07))); 
        $Locals_rgb = substr ( $this->BUF[$i], 13, 3 * (2 << ( ord ( $this->BUF[$i]{10} ) & 0x07))); 
        $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 0) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . "\x0\x0"; 
        if ( $this->COL > -1 && ord($this->BUF[$i]{10}) & 0x80)

        { 
          for($j = 0; $j < (2 << (ord( $this->BUF[$i]{10}) & 0x07)); $j++ )
          { 
            if(ord ($Locals_rgb{3 * $j + 0}) == ($this->COL >> 0) & 0xFF && ord ( $Locals_rgb { 3 * $j + 1 } ) == ( $this->COL >> 8 ) & 0xFF && ord ( $Locals_rgb { 3 * $j + 2 } ) == ( $this->COL >> 16 ) & 0xFF )

            { 
              $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 1) . chr (( $d >> 0) & 0xFF) . chr (( $d >> 8) & 0xFF) . chr ($j) . "\x0"; 
              break; 
            } 
          } 

        } 
        switch ( $Locals_tmp { 0 } )

        { 
          case "!": 
            $Locals_img = substr($Locals_tmp, 8, 10); 
            $Locals_tmp = substr($Locals_tmp, 18, strlen ($Locals_tmp) - 18); 
            break; 
          case ",": 
            $Locals_img = substr($Locals_tmp, 0, 10); 
            $Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10); 
            break; 
        } 
        if ( ord ( $this->BUF[$i]{10} ) & 0x80 && $this->IMG > -1 )
        { 
          if ( $Global_len == $Locals_len )
          { 
            if ( GIFEncoder::GIFBlockCompare ( $Global_rgb, $Locals_rgb, $Global_len ) )
            { 
              $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp ); 
            } 
            else
            { 
              $byte = ord ( $Locals_img{9}); 
              $byte |= 0x80; 
              $byte &= 0xF8; 
              $byte |= ( ord ( $this->BUF [ 0 ]{10}) & 0x07); 

              $Locals_img{9} = chr($byte); 

              $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp); 
            } 
          } 
          else

          { 
            $byte = ord($Locals_img{9}); 
            $byte |= 0x80; 
            $byte &= 0xF8; 
            $byte |= (ord($this->BUF[$i]{10}) & 0x07); 
            $Locals_img {9} = chr($byte); 
            $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp); 
          } 
        } 
        else
        { 
          $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp ); 
        } 
        $this->IMG = 1; 

      } 
      function GIFAddFooter ( ) { 
        $this->GIF .= ";"; 
      } 
      function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len )
      { 
        for ( $i = 0; $i < $Len; $i++ )

        { 

          if($GlobalBlock { 3 * $i + 0 } != $LocalBlock { 3 * $i + 0 } || $GlobalBlock { 3 * $i + 1 } != $LocalBlock { 3 * $i + 1 } || $GlobalBlock { 3 * $i + 2 } != $LocalBlock{3 * $i + 2})
          { 
            return ( 0 ); 
          } 
        } 

        return ( 1 ); 
      } 
      function GIFWord ( $int )
      { 
        return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) ); 
      } 

      function GetAnimation ( )
      { 
        return ($this->GIF); 
      } 
    }

第二步:验证码生成,创建yzimg.php,并引用入文件ImageCode.php。代码如下:


    <?php
    if(!isset($_SESSION)){
      session_start();
    }
    require_once(dirname(__FILE__)."ImageCode.php");
    unset($_SESSION['yzm']);
    $randCode = '';
    $chars = 'abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPRSTUVWXYZ23456789';
    for ( $i = 0; $i < 4; $i++ )
    {
      $randCode .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
    }
    $_SESSION['yzm']=$randCode;     // 记录session
    ImageCode($randCode, 60);

    /*方法二*/
    /*$authstr = mt_rand(1000, 9999);  // 生成随机字符串
    $_SESSION['yzm'] = $authstr;  // 记录session
    ImageCode($authstr, 60);  // 显示GIF动画*/
    ?>

第三步:调用和显示验证码,在需要添加验证码的页面加入以下代码,代码如下:


    <input name="yzm" type="text" class="input1" size="12" style="width:70px;"/>
             <SCRIPT LANGUAGE="JavaScript">
    <!--
    document.write('<img id="yz_Img" name="imageField" class="yz_Img" title="刷新验证码" onclick="this.src=this.src+Math.random();" src="yzimg.php?'+Math.random()+'">');
    //-->
    </SCRIPT>

以上就是为大家分享的如何使用php生成动态验证码的相应代码,希望对大家的学习有所帮助。

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