js控制图片按比例缩放

缩放代码：

1. <script type="text/javascript">

2. //图片按比例缩放

3. var flag = false;

4. function DrawImage(ImgD, iwidth, iheight) {

5. //参数(图片,允许的宽度,允许的高度)

6. var image = new Image();

7. image.src = ImgD.src;

8. if (image.width > 0 && image.height > 0) {

9. flag = true;

10. if (image.width / image.height >= iwidth / iheight) {

11. if (image.width > iwidth) {

12. ImgD.width = iwidth;

13. ImgD.height = (image.height * iwidth) / image.width;

14. } else {

15. ImgD.width = image.width;

16. ImgD.height = image.height;

17. }

18. ImgD.alt = image.width + "×" + image.height;

19. }

20. else {

21. if (image.height > iheight) {

22. ImgD.height = iheight;

23. ImgD.width = (image.width * iheight) / image.height;

24. } else {

25. ImgD.width = image.width;

26. ImgD.height = image.height;

27. }

28. ImgD.alt = image.width + "×" + image.height;

29. }

30. }

31. }

32. </script>

页面代码：

1. <img onload="javascript:DrawImage(this,89,63)" src="http://www.baidu.com/img/baidu_logo.gif" width="89" height="63" border="0" />

觉得不错的发个言！