正则匹配 替换..追加..

Posted 2020-09-20 查克拉的觉醒

这里都是以图片中的元素为例：

 

匹配出IMG标签中alt的值:

 1 Regex reg = new Regex(@"(?is)(?<=<img[^>]*alt="")[^""]*(?=""[^>]*>)"); 

 

替换alt 内容：

var replace = "alt=\'要替换的内容\' ";

source = Regex.Replace(source, "alt=\\"\\"", replace);

上面那个并不严谨

var replace = " 替换内容 ";

source = Regex.Replace(source, @"(?is)(?<=<img[^>]*alt="")[^""]*(?=""[^>]*>)", replace);

自己先定义规则，然后替换

1 Regex r = new Regex(@"(?is)(?<=<img[^>]*alt="")");
2 
3 var replace = " 替换内容 ";
4 
5 source = r.Replace(source, new MatchEvaluator(x => replace));  

 

参考： http://bbs.csdn.net/topics/390320097

　　　 https://q.cnblogs.com/q/60920/