Introducing a php high-security verification code generation program. This generation program needs to call some font libraries. You can call some fonts that come with your system. Of course, you can also like Dedecms also puts the fonts in a directory so that they can be used on the server.

Verification codes are often used on login pages, message pages, and registration pages. The principle of verification codes is very simple: use the GD library to create a picture. Of course, the picture must be added with the necessary interference code, and then save the SESSION on the server side, waiting for the user Determine whether the sessions are the same when submitting.

A php verification code style class. Generating verification codes with PHP is not as difficult as imagined. Instantiate the object and set the width and width of the verification code image. height and the length of the verification code. Create pictures, interfere with colors, interfere with points, interfere with lines, and write verification codes into pictures.

A PHP custom verification code class, Create the original characters of the verification code, output the image, write the verification code, draw the interference line, get the verification code, and output the verification code. Friends who like it can download it for reference. If they have better verification codes, they can send them over for everyone to learn and reference together.

A customized PHP verification code code, image object, width, height, verification code length, random string, y-axis coordinate value , random color, background color red, green and blue, default is light gray, Verification code length, picture width, height are required data when instantiating the class , Set the background color of the picture, the default is light gray background ## .

Describes the simple and practical verification code class implemented in PHP, $image->config('width', 'height', 'number of characters', 'verification code session index'), $image->create();//This will output an image to the browser, generate the verification code, generate the verification code image , Set the interference pixels of the picture, Draw the verification codes one by one on the verification code picture.

Introducing a php Alibaba Cloud SMS verification code sending class, The account SMS activation status is incorrect, The SMS signature is incorrect or The signature status is incorrect, The SMS template code is incorrect or the template status is incorrect, The target mobile phone number is incorrect, and the number sent at a time cannot exceed 100,The variables in the SMS template are not in json format. The variables in the SMS template do not match the template content. The variables cannot be URLs. You can solidify the variables in In the template #.

A PHP encapsulated verification code tool class, Initialize the associative array of attributes, Generate verification code images, Get the verification code random string , 增加干扰点，增加干扰线，用户提交的验证码，验证验证码，验证码不区分大小写。

A PHP verification code class code is shared (encapsulated into a class) for learning reference by friends who need it. After being encapsulated into a class, a constructor is added, which makes it more convenient to use. You can also continue to improve this verification code class, such as adding a destructor, how to save memory, etc.

I saw on the Internet that using ValidateCode written in PHP to generate a verification code class, I feel good about it, so I used it to analyze and learn. $charset is a random factor. Here, several characters that are difficult to distinguish are removed, such as letters "i, l, o, q" and numbers "0,1". If necessary, you can add some Chinese or other characters or calculations, etc. When generating verification code text on an image, the position of the text on the image and the color of each text are mainly considered. Control the x-axis position of the n-th text = (image width / verification code length) * (n-1) random offset number; where n = {d1....n} Control the y-axis position of the nth text = image height / 2 random offset number; mt_rand(0, 156) randomly selects the text color. The purpose of 0-156 is to select a darker color. mt_rand(-30, 30) Random text rotation.

Mainly introduces the click captcha click verification code class example implemented by PHP. Different from the traditional verification code in the past, this verification code class allows mobile phone users to click on a certain location to confirm the verification code, which is very practical Most of the commonly used form verification codes require user input, but this will be inconvenient for mobile users. If mobile users visit, they don’t need to enter it, but click a certain location to confirm the verification code, which will be much more convenient.

Detailed analysis and introduction of the encapsulated verification code class implemented by PHP. Write a verification code class in PHP and encapsulate it. Output the image to the browser by accessing this method, Get the randomly created verification code string by calling this method.