thinkphp3.2 click refresh to generate verification code_php tips

Before I introduce how to use the thinkphp3.2 verification code, I will first introduce the ThinkPHP verification code in detail. The specific content is as follows

ThinkPHP has built-in support for verification codes and can be used directly. To use the verification code, you need to import the ORG.Util.Image class library and ORG.Util.String class library in the extended class library.
Verification code method
We add a verify method to the module class to display the verification code. The simplest example:

Public function verify(){
  // 导入Image类库
  import("ORG.Util.Image");
  Image::buildImageVerify();
}

The import method is ThinkPHP’s built-in class library and file import method. The file imported in the above example is the Lib/ORG/Util/Image.class.php file in the ThinkPHP system directory. If the Image class library has been copied to the current project, such as Lib/ORG, you can use:

import("@.Util.Image");

The import method is ThinkPHP’s built-in class library and file import method. The file imported in the above example is the Lib/ORG/Util/Image.class.php file in the ThinkPHP system directory.
Access verification code
You can access the verification code method directly in the browser to determine whether the verification code can be displayed normally:
http://127.0.0.1/index.php/Public/verify
If everything goes well, the verification code will appear as follows:

Use verification code in form
To use the verification code in the form page, it is called with the html img tag:

<input type="text" name="verify">
<img  id="verifyImg" src="-Article-verify" onClick="changeVerify()" title="点击刷新thinkphp3.2 click refresh to generate verification code_php tips" / alt="thinkphp3.2 click refresh to generate verification code_php tips" >

The src attribute value is the verification code method access address, which varies depending on the actual situation.
Verification code refresh
When the verification code image is clicked, the JavaScript changeVerify() function is triggered to re-read the verification code, thereby refreshing the verification code. The function reference is as follows:

<script language="JavaScript">
function changeVerify(){
 var timenow = new Date().getTime();
 document.getElementById('verifyImg').src='-Article/verify/'+timenow; 
}
</script>

Verification code verification
When calling the verification code verify, buildImageVerify will record the MD5 information of this verification code. In the form verification operation, use the following method to check whether the verification code is correct:

if($_SESSION['verify'] != md5($_POST['verify'])) {
  $this->error('thinkphp3.2 click refresh to generate verification code_php tips错误！');
}

The verify name in $_SESSION['verify'] is the default SESSION registration name of the buildImageVerify method. For details, see the buildImageVerify syntax.
The above example demonstrates the simplest way to use ThinkPHP verification code. The verification code in the above example is 4 digits. If you want to use more styles of verification codes and Chinese verification codes, see the rest of this section: "ThinkPHP uses different styles and Chinese verification codes".
The reason why the verification code is not displayed
It is found that the verification code cannot be displayed. The possible reasons are as follows:
1. Whether PHP has installed GD library support.
2. Is there any output before output (especially UTF8 BOM header information output).
3. Whether the Image class library is imported correctly.
4. If it is a form page, please check whether the verification code display method is correctly called.

The following will introduce to you how to generate the verification code and click to refresh the verification code in thinkphp3.2. The specific content is as follows

1. Instantiate the class that generates the verification code (this method is placed in IndexController for easy access)

/** 
 * 
 * thinkphp3.2 click refresh to generate verification code_php tips生成 
 */ 
public function verify_c(){ 
  $Verify = new \Think\Verify(); 
  $Verify->fontSize = 18; 
  $Verify->length  = 4; 
  $Verify->useNoise = false; 
  $Verify->codeSet = '0123456789'; 
  $Verify->imageW = 130; 
  $Verify->imageH = 50; 
  //$Verify->expire = 600; 
  $Verify->entry(); 
} 

2. The src attribute of the image that the front desk needs to generate a verification code points to

<p class="top15 captcha" id="captcha-container"> 
 <input name="verify" width="50%" height="50" class="captcha-text" placeholder="thinkphp3.2 click refresh to generate verification code_php tips" type="text">         
 <img    style="max-width:90%" class="left15"  style="max-width:90%" alt="thinkphp3.2 click refresh to generate verification code_php tips" src="{:U('Home/Index/verify_c',array())}" title="点击刷新"> 
</p> 

3. After writing the above, the verification code for page initialization will appear. What is written next is to refresh the new verification code image after clicking on the verification code image (this is done by modifying the src attribute of the image through jquery. The request processing function is the same, except that a random number is added after the request to distinguish the request for the previous picture)

// thinkphp3.2 click refresh to generate verification code_php tips生成 
var captcha_img = $('#captcha-container').find('img') 
var verifyimg = captcha_img.attr("src"); 
captcha_img.attr('title', '点击刷新'); 
captcha_img.click(function(){ 
  if( verifyimg.indexOf('?')>0){ 
    $(this).attr("src", verifyimg+'&random='+Math.random()); 
  }else{ 
    $(this).attr("src", verifyimg.replace(/\?.*$/,'')+'?'+Math.random()); 
  } 
}); 

4. Verify whether the verification code is entered correctly
a. Add a global function to function.php in the common directory

/** 
 * thinkphp3.2 click refresh to generate verification code_php tips检查 
 */ 
function check_verify($code, $id = ""){ 
  $verify = new \Think\Verify(); 
  return $verify->check($code, $id); 
} 

b. Add check code in the processing method corresponding to the controller of form submission

// 检查thinkphp3.2 click refresh to generate verification code_php tips 
$verify = I('param.verify',''); 
if(!check_verify($verify)){ 
  $this->error("亲，thinkphp3.2 click refresh to generate verification code_php tips输错了哦！",$this->site_url,9); 
} 

Now you can use the tp3.2 verification code.
Supplement: When I was writing, I put the fourth step b into an ajax for verification and returned a test result. Then we determine whether to submit the form based on the returned results. However, after the verification code passes the first verification, the second time will not work. I haven’t figured out the reason yet.

This is the entire content of this article. There is a small question at the end of the article. I hope you can come up with a solution. I also hope this article will be helpful to your study.