Generate/Verify CAPTCHA function with thinkphp

First understand some of the functions in the parent class Verity.class.php (thinkphp/library/think/verity.class.php)

1:check () Verify that the verification code is correct

2:entry () output The verification code and save the value of the verification code in the session

3:authcode () Encryption Verification code (this method is called in the Check () method)

The controller generates the CAPTCHA code:

//Verification Code    functionverifyimg () {//Verification Code Configuration        $cfg=Array(           ' Imageh ' = 30,//Verification Code Picture height' Imagew ' = 100,//Verification Code Picture width' FontSize ' = 15,//captcha font size (px)' Length ' = 4,//Verify number of code bits' Fontttf ' = ' 4.ttf ',//captcha font, not set random get        ); //instantiate the Verify class to automatically call the constructor and pass the $cfg information to $config        $verify=NewVerify ($cfg); $verify-entry();//Output Verification Code}

Verification code displayed at front desk

<!-- Group/Controller/method --
<src= "<{$smarty. const.__controller__}>/verifyimg"  = "this.src= ' <{$smarty. const.__controller__}>/verifyimg/' +math.random ()" alt = "Verification Code" />

Controller calibration Code (take login as an example)

//Login    functionLogin () {//two logic: show, collect        if(!Empty($_post)) {            $verify=NewVerify (); //Receive Verification Code            $captcha=$_post[' Captcha ']; //Check () method check Verification code            if($verify-Check($captcha)) {                EchoCorrect; }Else{                EchoError; }        }       //call The View view       $this-display (); }

Use thinkphp to implement build/verify Captcha function