PHP generates verification code with snowflake background_PHP tutorial

效果参考(附源码)http://mail.htjs.net/yanzhengma/test.php

();?>

//Check the check code
if(isset($HTTP_POST_VARS["sub"])):
if ($HTTP_POST_VARS["number"] != $HTTP_SESSION_VARS[login_check_number] || empty($HTTP_POST_VARS["number" ])){
echo "The check code is incorrect!" ;
}else{
echo"Verification code passed!";
}
endif;
show_source('test.php ');
//The source code of the above page


//The following is the source code to generate the verification code
show_source('YanZhengMa.php');
?>
<font color="#000000"><font face="新宋体" color="#0000cc"><?php <BR>session_start</font><font face="新宋体"><font color="#006600">(); <br></font><font color="#0000cc">session_register</font><font color="#006600">(</font><font color="#cc0000">"login_check_number"</font></font><font face="新宋体" color="#006600">); <br></font><font face="新宋体"><font color="#ff9900">//I saw the verification code effect on chianren last night, so I considered it After a while, a similar function was completed using PHP's GD library <br>//Generate the background first, and then put the generated verification code <br></font><font color="#0000cc">$img_height</font><font color="#006600">=</font><font color="#0000cc">120</font><font color="#006600">; </font></font><font face="新宋体"><font color="#ff9900">//First define the length and width of the image<br></font><font color="#0000cc">$img_width</font><font color="#006600">=</font><font color="#0000cc">40</font></font><font face="新宋体"><font color="#006600">; <br>if(</font><font color="#0000cc">$HTTP_GET_VARS</font><font color="#006600">[</font><font color="#cc0000">"act"</font><font color="#006600">]== </font><font color="#cc0000">"init"</font></font><font face="新宋体" color="#006600">){ <br> </font><font face="新宋体"><font color="#ff9900">//srand(microtime() * 100000); //After PHP420, srand is not necessary <br> </font><font color="#006600">for(</font><font color="#0000cc">$Tmpa</font><font color="#006600">=</font><font color="#0000cc">0</font><font color="#006600">;</font><font color="#0000cc">$Tmpa</font><font color="#006600"><font color="#0000cc">4</font><font color="#006600">;</font><font color="#0000cc">$Tmpa</font></font><font face="新宋体"><font color="#006600">+ +){ <br>     </font><font color="#0000cc">$nmsg</font><font color="#006600">.=</font><font color="#0000cc">dechex</font><font color="#006600">(</font><font color="#0000cc">rand</font><font color="#006600">( </font><font color="#0000cc">0</font><font color="#006600">,</font><font color="#0000cc">15</font></font><font face="新宋体" color="#006600">)); <br> }</font><font face="新宋体"><font color="#ff9900">//by sports98 <br><br><br> </font><font color="#0000cc">$HTTP_SESSION_VARS</font><font color="#006600">[</font><font color="#0000cc">login_check_number</font><font color="#006600">] = </font><font color="#0000cc">$nmsg</font> </font><font face="新宋体" color="#006600">; <br><br> </font><font face="新宋体"><font color="#ff9900">//$HTTP_SESSION_VARS[login_check_number] = strval(mt_rand("1111","9999")); //Generate 4-digit Random numbers, put them into the session <br> //Who can add something that can generate letters and numbers at the same time? ?----Completed by sports98 <br><br> </font><font color="#0000cc">$aimg </font><font color="#006600">= </font><font color="#0000cc">imageCreate</font><font color="#006600">(</font><font color="#0000cc">$ img_height</font><font color="#006600">,</font><font color="#0000cc">$img_width</font><font color="#006600">); </font></font>(<font face="新宋体"><font color="#ff9900">$aimg<br></font>, <font color="#0000cc"></font>255<font color="#006600"></font>,<font color="#0000cc"></font>255<font color="#006600"></font>, <font color="#0000cc"></font>255<font color="#006600"></font>); 🎜><font color="#0000cc">$black </font><font color="#006600">= </font><font color="#0000cc">ImageColorAllocate</font><font color="#006600">(</font></font>$aimg<font face="新宋体"><font color="#ff9900">, <br></font>0 <font color="#0000cc"></font>,<font color="#006600"></font>0<font color="#0000cc"></font>,<font color="#006600"></font>0<font color="#0000cc"></font>); Define the required black <font color="#006600"> </font><font color="#0000cc">ImageRectangle</font><font color="#006600">(</font><font color="#0000cc">$aimg</font><font color="#006600">,</font><font color="#0000cc">0</font><font color="#006600">, </font></font>0<font face="新宋体"><font color="#ff9900">,<br></font>$img_height<font color="#0000cc"></font>-<font color="#006600"></font>1<font color="#0000cc"></font>,<font color="#006600"></font>$ img_width<font color="#0000cc"></font>-<font color="#006600"></font>1<font color="#0000cc"></font>,<font color="#006600"></font>$black<font color="#0000cc"></font>);<font color="#006600"></font><font color="#0000cc"></font> //First create a black rectangle to surround the image <font color="#006600"></font> //Now it’s time to generate the snowflake background, which is actually to generate some symbols on the image <font color="#0000cc"> </font><font color="#006600">for (</font><font color="#0000cc"> $i</font><font color="#006600">=</font><font color="#0000cc">1</font><font color="#006600">; </font></font>$i<font face="新宋体"><font color="#ff9900"><br>100<br> </font>; <font color="#006600"></font>$i<font color="#0000cc"></font>++) { <font color="#006600"></font><font color="#0000cc"></font>//Test with 100 first <font color="#006600"> </font><font color="#0000cc">imageString</font><font color="#006600">(</font><font color="#0000cc">$aimg</font><font color="#006600">,</font><font color="#0000cc">1</font><font color="#006600">,</font></font>mt_rand<font face="新宋体"><font color="#ff9900">(<br></font>1<font color="#0000cc"></font>,<font color="#006600"></font>$img_height<font color="#0000cc"></font>),<font color="#006600"></font>mt_rand<font color="#0000cc"></font>(<font color="#006600"></font>1<font color="#0000cc"></font>,<font color="#006600"></font>$img_width<font color="#0000cc"></font>),<font color="#006600"></font>"*"<font color="#0000cc"></font>,<font color="#006600"></font>imageColorAllocate<font color="#0000cc"></font>(<font color="#006600"></font>$aimg<font color="#0000cc"></font>,<font color="#006600"></font>mt_rand<font color="#0000cc"></font>(<font color="#006600"></font>200<font color="#cc0000"></font>,<font color="#006600"></font>255<font color="#0000cc"></font>),<font color="#006600"></font>mt_rand<font color="#0000cc"></font>(<font color="#006600"></font>200<font color="#0000cc"></font>,<font color="#006600"></font>255<font color="#0000cc"></font>),<font color="#006600"></font>mt_rand<font color="#0000cc"></font>(<font color="#006600"></font>200<font color="#0000cc"></font>,<font color="#006600"></font>255<font color="#0000cc"></font><font color="#006600">))); </font> <font color="#0000cc"></font>//Ha, you see, it’s not actually a snowflake, it’s just an * sign. In order to make them look "messy and colorful", you have to use random numbers for their position, color, and even size when generating them one by one. This can be done with rand() or mt_rand. <font color="#006600"> </font><font color="#0000cc">} </font><font color="#006600"> </font><font color="#0000cc"></font>//The background is generated above, now it’s time to put the generated random numbers.The principle is similar to the above. Random numbers are placed one by one, and their positions, sizes, and colors are all used as random numbers~~ <br> //In order to distinguish it from the background, the color here does not exceed 200, and the color above does not exceed 200. Less than 200 <br> </font><font color="#006600">for (</font><font color="#0000cc">$i</font><font color="#006600">=</font><font color="#0000cc">0</font><font color="#006600">;</font><font color="#0000cc">$i </font><font color="#006600"><font color="#0000cc">strlen</font><font color="#006600">(</font><font color="#0000cc">$HTTP_SESSION_VARS</font><font color="#006600">[</font><font color="#0000cc">login_check_number</font><font color="#006600"> ]);</font><font color="#0000cc">$i</font></font><font face="新宋体"><font color="#006600">++){ <br>       </font><font color="#0000cc">imageString</font><font color="#006600">(</font><font color="#0000cc"> $aimg</font><font color="#006600">, </font><font color="#0000cc">mt_rand</font><font color="#006600">(</font><font color="#0000cc">3</font><font color="#006600">,</font><font color="#0000cc">5</font><font color="#006600"> ),</font><font color="#0000cc">$i</font><font color="#006600">*</font><font color="#0000cc">$img_height</font><font color="#006600">/</font><font color="#0000cc">4</font><font color="#006600">+</font><font color="#0000cc">mt_rand</font><font color="#006600">(</font><font color="#0000cc">1</font><font color="#006600">,</font><font color="#0000cc">10</font><font color="#006600">),</font><font color="#0000cc">mt_rand</font><font color="#006600">(</font><font color="#0000cc">1</font><font color="#006600">,</font><font color="#0000cc">$img_width</font><font color="#006600">/</font><font color="#0000cc">2</font><font color="#006600">), </font> <font color="#0000cc">$HTTP_SESSION_VARS</font><font color="#006600">[</font><font color="#0000cc">login_check_number</font><font color="#006600">][</font><font color="#0000cc">$i</font><font color="#006600">],</font><font color="#0000cc">imageColorAllocate </font><font color="#006600">(</font><font color="#0000cc">$aimg</font><font color="#006600">,</font><font color="#0000cc">mt_rand</font><font color="#006600">(</font><font color="#0000cc">0</font><font color="#006600">, </font><font color="#0000cc">100</font><font color="#006600">),</font><font color="#0000cc">mt_rand</font><font color="#006600">(</font><font color="#0000cc">0</font><font color="#006600">,</font><font color="#0000cc">150 </font><font color="#006600">),</font><font color="#0000cc">mt_rand</font><font color="#006600">(</font><font color="#0000cc">0</font><font color="#006600">,</font><font color="#0000cc">200</font></font><font face="新宋体"><font color="#006600">))); <br> } <br> >); </font><font color="#0000cc"></font><font color="#006600">//Tell the browser that the following data is an image, rather than displaying it as text </font> <font color="#cc0000"></font>ImagePng<font color="#006600"></font>(</font><font face="新宋体">$aimg<font color="#ff9900"><br>);     </font><font color="#0000cc"></font><font color="#006600">//Generate png format. . . Hehe, the effect is quite similar. . . </font> <font color="#0000cc"></font>ImageDestroy<font color="#006600"></font>(</font><font face="新宋体">$aimg<font color="#ff9900"><br></font><font color="#0000cc">); </font>} <font color="#006600"></font><font color="#0000cc"></font>?></font> <font face="新宋体"><font color="#006600"><br><br> <br> </font><font color="#0000cc"></font>http://www.bkjia.com/PHPjc/314647.html</font></font>www.bkjia.com</font>

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TechArticleEffect reference (with source code) http://mail.htjs.net/yanzhengma/test.php ?session_start ( ); ? FORM METHOD=POST ACTION="" input type=text name=number maxlength=4img src="YanZhengMa.php?act=i...