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;$i<6;$i++){
4. $pos = rand(0,36);
5. $str .= $string{$pos};
6. }
8. $img_handle = ImageCreate (60, 20) or die ("Cannot Create image");
9. //Image size (x,y)
10. $back_color = ImageColorAllocate($img_handle, 255, 255, 255);
11. //Background color RBG
12. $txt_color = ImageColorAllocate($img_handle, 0, 0, 0);
13. //Text Color RBG
14. ImageString($img_handle, 31, 5, 0, $str, $txt_color);
15. Imagepng($img_handle);
17. session_start();
18. $_SESSION['img_number'] = $str;
19. ?>

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;$i<6;$i++){
13. $pos = rand(0,36);
14. $str .= $string{$pos};
15. }
17. $img_handle = ImageCreate (60, 20) or die ("Cannot Create image");
18. //Image size (x,y)
19. $back_color = ImageColorAllocate($img_handle, 255, 255, 255);
20. //Background color RBG
21. $txt_color = ImageColorAllocate($img_handle, 0, 0, 0);
22. //Text Color RBG
23. ImageString($img_handle, 31, 5, 0, $str, $txt_color);
24. Imagepng($img_handle);
26. session_start();
27. $_SESSION['img_number'] = $str;
28. ?>
30. form.php

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. ?>