C＃替换了这些标签之间的所有内容

<meta name=\"description\" content=\" \" /> 

this.ltlTags.Text = this.HeaderTags; 

this.ltlTags.Text = this.HeaderTags.Replace(
    \"everything inside the content attribute of the meta tag\", \"with this text\"); 

this.ltlTags.Text = Regex.Replace(this.HeaderTags,
    \"content=\\\"[^\\\"]*\\\"\", \"content=\\\"\" + yourStuff + \"\\\"\");

content=\"<anything>\"

content=\"<yourStuff>\"

this.ltlTags.Text = this.HeaderTags.Replace(\"<meta name=\\\"description\\\" content=\\\" \\\" />\",
                          \"<meta name=\\\"description\\\" content=\\\"new text here\\\" />\");