求一正则表达式，感谢！！

Question

如:
<IMG id=abf1c8.jpg class=photo src="http://wap.tie.com/data/test/ab6e374ceeabc93fc7d33f35ff1c8/ab6efc7d33f35ff1c8.jpg" width=400 height=500>
<IMG id=ab6374.jpg src="http://wap.tie.com/data/test/ab6e37fc7d33f35ff1c8/ab6e374ceeab4dec93fc35ff1c8.jpg?"width=400 height=520>
<IMG id=a431c8.jpg class=photo src="http://wap.tie.com/data/test/ab6e374ceeab4dec9ff1c8/ab6e374c7d33f35ff1c8.jpg?0702214045" width=400 height=30>
<IMG src="test.jpg" class=photo src="http://wap.tie.com/data/test/ab6e37fc7d33f35ff1c8/ab6e374ceeab4dec93fc35ff1c8.jpg">规则:<IMG　开头，里面包含id这个属性，并且每个<IMG　标签里面有　width和height　　
结果：把符合以上规则标签里面的 width=400 height=""　去掉．
比如第一个去的结果为：
<IMG id=abf1c8.jpg class=photo src="http://wap.tie.com/data/test/ab6e374ceeabc93fc7d33f35ff1c8/ab6efc7d33f35ff1c8.jpg">

Answer 1

(?is)(?<=<IMG[^>]*?id=['"\s]?[^"']*?['"\s]?[^>]*?)width=[^>]*height=[^>]*(?=[^>]*?>)string html="你的源码";
html=Regex.Replace(html,@"(?is)(?<=<IMG[^>]*?id=['""\s]?[^""']*?['""\s]?[^>]*?)width=[^>]*height=[^>]*(?=[^>]*?>)","");

Answer 2

 tempStr = Regex.Replace(tempStr, @"(?i)(?<=<img[^>]*?id=[^>]*?)(?:width|height)=(['""]?)[^'""\s]*?\1(?=\s|/|>)",string.Empty);