php进行GB2312与UTF8编码转换的代码

3. Class GB2UTF8

4. {
5. var $gb; // 待转换的GB2312字符串
6. var $utf8; // 转换后的UTF8字符串
7. var $CodeTable; // 转换过程中使用的GB2312代码文件数组
8. var $ErrorMsg; // 转换过程之中的错误讯息

9. function GB2UTF8($InStr="")

10. {
11. $this->gb=$InStr;
12. $this->SetGb2312();
13. ($this->gb=="")?0:$this->Convert();
14. }

15. function SetGb2312($InStr="gb2312.txt")

16. { // 设置gb2312代码文件，默认为gb2312.txt
17. $this->ErrorMsg="";
18. $tmp=@file($InStr);
19. if (!$tmp) {
20. $this->ErrorMsg="No GB2312";
21. return false;
22. }
23. $this->CodeTable=array();
24. while(list($key,$value)=each($tmp)) {
25. $this->CodeTable[hexdec(substr($value,0,6))]=substr($value,7,6);
26. }
27. }

28. function Convert()

29. { // 转换GB2312字符串到UTF8字符串，需预先设置$gb
30. $this->utf8="";
31. if(!trim($this->gb) || $this->ErrorMsg!="") {
32. return ($this->utf8=$this->ErrorMsg);
33. }
34. $str=$this->gb;

35. while($str) {

36. if (ord(substr($str,0,1))>127)
37. {
38. $tmp=substr($str,0,2);
39. $str=substr($str,2,strlen($str));
40. $tmp=$this->U2UTF8(hexdec($this->CodeTable[hexdec(bin2hex($tmp))-0x8080]));
41. for($i=0;$i$this->utf8.=chr(substr($tmp,$i,3));
42. }
43. else
44. {
45. $tmp=substr($str,0,1);
46. $str=substr($str,1,strlen($str));
47. $this->utf8.=$tmp;
48. }
49. }
50. return $this->utf8;
51. }

52. function U2UTF8($InStr)

53. {
54. for($i=0;$i$str="";
55. if ($InStr < 0x80) {
56. $str.=ord($InStr);
57. }
58. else if ($InStr < 0x800) {
59. $str.=(0xC0 | $InStr>>6);
60. $str.=(0x80 | $InStr & 0x3F);
61. }
62. else if ($InStr < 0x10000) {
63. $str.=(0xE0 | $InStr>>12);
64. $str.=(0x80 | $InStr>>6 & 0x3F);
65. $str.=(0x80 | $InStr & 0x3F);
66. }
67. else if ($InStr < 0x200000) {
68. $str.=(0xF0 | $InStr>>18);
69. $str.=(0x80 | $InStr>>12 & 0x3F);
70. $str.=(0x80 | $InStr>>6 & 0x3F);
71. $str.=(0x80 | $InStr & 0x3F);
72. }
73. return $str;
74. }
75. }
76. ?>

测试下，看看效果：

2. Header("Content-type: image/png");
3. $im = imagecreate(400,300);
4. $black = ImageColorAllocate($im, 0,0,0);
5. $white = ImageColorAllocate($im, 184,44,6);
6. include("gb2utf8.php");
7. $obj=new gb2utf8();
8. $obj->gb="123abc中国456def测试正确";
9. $obj->Convert();
10. ImageTTFText($im, 20, 0, 5, 50, $white, "SIMKAI.TTF", $obj->utf8);
11. ImagePNG($im);
12. ImageDestroy($im);
13. ?>

注解： 需要正确设置font文件，请先确认是否能够使用font直接（不使用gb2utf8）输出英文。