php实现简单的图片验证码

这是最简单的图片验证码：

image.php

1. header("Content-type: image/png");
2. $string = "abcdefghijklmnopqrstuvwxyz0123456789";
3. for($i=0;$i $pos = rand(0,36);
4. $str .= $string{$pos};
5. }
7. $img_handle = ImageCreate (60, 20) or die ("Cannot Create image");
8. //Image size (x,y)
9. $back_color = ImageColorAllocate($img_handle, 255, 255, 255);
10. //Background color RBG
11. $txt_color = ImageColorAllocate($img_handle, 0, 0, 0);
12. //Text Color RBG
13. ImageString($img_handle, 31, 5, 0, $str, $txt_color);
14. Imagepng($img_handle);
16. session_start();
17. $_SESSION['img_number'] = $str;
18. ?>

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form.php

1. php实现简单的图片验证码
2. 更多 0
3. php
4. 验证码
6. 这是最简单的图片验证码：
8. image.php
10. header("Content-type: image/png");
11. $string = "abcdefghijklmnopqrstuvwxyz0123456789";
12. for($i=0;$i $pos = rand(0,36);
13. $str .= $string{$pos};
14. }
16. $img_handle = ImageCreate (60, 20) or die ("Cannot Create image");
17. //Image size (x,y)
18. $back_color = ImageColorAllocate($img_handle, 255, 255, 255);
19. //Background color RBG
20. $txt_color = ImageColorAllocate($img_handle, 0, 0, 0);
21. //Text Color RBG
22. ImageString($img_handle, 31, 5, 0, $str, $txt_color);
23. Imagepng($img_handle);
25. session_start();
26. $_SESSION['img_number'] = $str;
27. ?>
29. form.php
31. 

    
    

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result.php

1. session_start();
2. if($_SESSION['img_number'] != $_POST['num']){
3. echo'The number you entered doesn't match the image.
   
4. Try Again
   ';
5. }else{
6. echo'The numbers Match!
   
7. Try Again
   ';
8. }
9. ?>

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验证码, php