这是一款经典实用的生成小图的php代码,有专业素语来讲就是php 生成缩略图代码,实例代码如下:

1. # 显示图形及连接
2. function showdir ($adirectory, $i)
3. {
4. global $browsedir;
5. $start = $i;
6. # 更改 $maxcols 及 $maximages 可改变每一页显示的小图的行数与列数。
7. $maxcols = 2;
8. $maximages = 6;
9. $maximages = $i + ($maximages - 3);
10. # 更改 $imagemaxwidth 及 $imagemaxheight 可改变显示小图的宽度与高度。
11. $imagemaxwidth = 100;
12. $imagemaxheight = 100;
13. # 计算高度与宽度的比例。
14. $imagemaxratio = $imagemaxwidth / $imagemaxheight;
15. $ndirectory = sizeof ($adirectory);
16. echo (table_start);
17. for ($i; $i<=$maximages;)
18. {
19. echo (row_start);
20. for ($icols=1; $icols<=$maxcols; $icols++)
21. {
22. echo (col_start);
23. $imagefilename = $adirectory[++$i];
24. if (strlen($imagefilename)>0)
25. {
26. $imagepath = $browsedir."/".$imagefilename;
27. $imagesize = getimagesize ($imagepath);
28. if ($imagesize)
29. {
30. $imagewidth = $imagesize[0];
31. $imageheight = $imagesize[1];
32. $imageratio = $imagewidth / $imageheight;
33. if ($imageratio > $imagemaxratio)
34. {
35. $imageoutputwidth = $imagemaxwidth;
36. $imageoutputheight = ceil ($imagemaxwidth/$imagewidth*$imageheight);
37. }
38. else if ($imageratio < $imagemaxratio)
39. {
40. $imageoutputheight = $imagemaxheight;
41. $imageoutputwidth = ceil ($imagemaxheight/$imageheight*$imagewidth);
42. } else
43. {
44. $imageoutputwidth = $imagemaxwidth;
45. $imageoutputheight = $imagemaxheight;
46. }
47. # 显示图形
48. echo (a_start.$imagepath.a_close);
49. echo (img_start.$imagepath.img_width.$imageoutputwidth.img_height.$imageoutputheight.img_end);
50. echo (line_break.$adirectory[$i]);
51. echo (a_end);
52. }
53. echo (col_end);
54. }
55. }
56. echo (row_end);
57. }
58. echo (table_end);
59. pagemenu ($browsedir, $ndirectory, $start);
60. }
61. function pagemenu ($browsedir, $ndirectory, $pg) {
62. echo "<br><center><font size="1" color="#000033">page:";
63. $pg_num = 1;
64. //开源代码phpfensi.com
65. for ($img_num = 0; $img_num <= $ndirectory;) {
66. if ($pg == $img_num) {
67. echo "<span class="menulink_1"><a href="thumb.php?browsedir=$browsedir&start=$img_num"> *$pg_num</a> <span>";
68. } else {
69. echo "<span class="menulink_2"><a href="thumb.php?browsedir=$browsedir&start=$img_num"> $pg_num</a> <span>";
70. }
71. # 建立其他页次的连接, 每页显示四张图, 故页数 $pg_num 每加 1 , $img_num 就加 4 。
72. $pg_num = $pg_num + 1;
73. $img_num = $img_num + 4;
74. }
75. echo "</font> ";
76. }
77. function dirtoarray ($browsedir, $extensions)
78. {
79. $nextensions = sizeof ($extensions);
80. $idirectory = 0;
81. $directory = dir($browsedir);
82. while ($entry = $directory->read())
83. {
84. for ($i=1; $i<=$nextensions; $i++)
85. {
86. $compare = stristr ($entry, $extensions[$i]);
87. if (strlen($compare) == strlen($extensions[$i]))
88. {
89. $adirectory[++$idirectory] = $entry;
90. break;
91. }
92. }
93. }
94. $directory->close();
95. return $adirectory;
96. }
97. #主程序
98. #变量 $browsedir 为图形文件放置的位置。
99. $browsedir="./images";
100. # 允许浏览的图形文件扩展名, 放置於数组中, 可自行增加。
101. $extensions[1] = "jpeg";
102. $extensions[2] = "jpg";
103. $extensions[3] = "gif";
104. $extensions[4] = "png";
105. showdir (dirtoarray ($browsedir, $extensions), $start);
106. define ("line_break", "<br>");
107. define ("table_start", "<table width=600> ");
108. define ("table_end", "</table> ");
109. define ("row_start", " <tr> ");
110. define ("row_end", " </tr> ");
111. define ("col_start", " <td align=center> ");
112. define ("col_end", " </td> ");
113. define ("img_start", "<img src=");
114. define ("img_end", ">");
115. define ("img_width", " width=");
116. define ("img_height", " height=");
117. define ("a_start", '<a href="');
118. define ("a_close", '">');
119. define ("a_end", "</a>");