How to encode special characters in XML

Question

My XML string contains a series of special characters:

&
egrave;
&
rsquo;
&
rsquo;
&
rsquo;
&
ldquo;
&
rdquo;
&
rsquo
&
agrave;
&
agrave;

I need to replace these special characters in the insert line in the database, and I have unsuccessfully used System.Net.WebUtility.HtmlEncode , can you help me?

string sql = "insert into rss (title, description, link, pubdate) values (?,?,?, " +
             " STR_TO_DATE(?, '%a, %d %b %Y %H:%i:%s GMT'));";

OdbcCommand command;
OdbcDataAdapter adpter = new OdbcDataAdapter();
connection.Open();
command = new OdbcCommand(sql, connection);
command.Parameters.AddWithValue("param1", System.Net.WebUtility.HtmlEncode(xmlTitle.InnerText.ToString()));
command.Parameters.AddWithValue("param2", System.Net.WebUtility.HtmlEncode(xmlDescription.InnerText.ToString()));
command.Parameters.AddWithValue("param3", System.Net.WebUtility.HtmlEncode(xmlLink.InnerText.ToString()));
command.Parameters.AddWithValue("param4", System.Net.WebUtility.HtmlEncode(xmlPubDate.InnerText.ToString()));
adpter.InsertCommand = command;
adpter.InsertCommand.ExecuteNonQuery();
connection.Close();

Answer 1

You can use HttpUtility.HtmlDecode or with .NET 4.0+, you can also use WebUtility.HtmlDecode

Answer 2

You can use your own .NET method to escape special characters in text. Of course, there are only 5 special characters, and 5 calls to Replace () will probably work, but I'm sure there must be something inline.

"&" "&"

, , SecurityElement. , - SecurityElement.Escape(string s) XML.

, , Infopath Text, , , "&" ,

XML

"<" to "&lt;"

">" to ">"

"\"" to """

"'" to "'"

"&" to "&"

"System.Security". . Http://msdn2.microsoft.com/en-us/library/system.security.securityelement.escape(VS.80).aspx

-

public static string EscapeXml( this string s )
{
  string toxml = s;
  if ( !string.IsNullOrEmpty( toxml ) )
  {
    // replace literal values with entities
    toxml = toxml.Replace( "&", "&" );
    toxml = toxml.Replace( "'", "'" );
    toxml = toxml.Replace( "\"", """ );
    toxml = toxml.Replace( ">", ">" );
    toxml = toxml.Replace( "<", "&lt;" );
  }
  return toxml;
}

public static string UnescapeXml( this string s )
{
  string unxml = s;
  if ( !string.IsNullOrEmpty( unxml ) )
  {
    // replace entities with literal values
    unxml = unxml.Replace( "&apos;", "'" );
    unxml = unxml.Replace( "&quot;", "\"" );
    unxml = unxml.Replace( "&gt;", ">" );
    unxml = unxml.Replace( "&lt;", "<" );
    unxml = unxml.Replace( "&amp;", "&" );
  }
  return unxml;
}

Answer 3

System.Net.WebUtility.HtmlEncode System.Net.WebUtility.HtmlDecode

Answer 4

Statement toxml = toxml.Replace( "&", "&" );

. , "&" (' ") & s;

Answer 5

:

    public static string ToXmlStr(string value) => String.IsNullOrEmpty(value) ? "" : value.Replace("&", "&amp;").Replace("'", "&apos;").Replace("\"", "&quot;").Replace(">", "&gt;").Replace("<", "&lt;");

    public static string FromXmlStr(string xmlStr) => String.IsNullOrEmpty(xmlStr) ? "" : xmlStr.Replace("&apos;", "'").Replace("&quot;", "\"").Replace("&gt;", ">").Replace("&lt;", "<").Replace("&amp;", "&");

    public static string ToMultilineXmlStr(string value) => String.IsNullOrEmpty(value) ? "" :
        value.Replace("\r", "").Split('\n').Aggregate(new StringBuilder(), (s, n) => s.Append("<p>").Append(ToXmlStr(n)).Append("</p>\n")).ToString();

Please note: for multi-line values ​​in xml, you usually need to enclose each line in <p> tag. So "<'&A'>\n<'&B'>" => "<p>&lt;&amp;A;&gt;</p><p>&lt;&amp;B;&gt;</p>" <p> tag. So "<'&A'>\n<'&B'>" => "<p>&lt;&amp;A;&gt;</p><p>&lt;&amp;B;&gt;</p>"

Answer 6

There are 3 other ways to do this from what you have tried:

1. Use string.Replace () 5 times
2. Use System.Web.HttpUtility.HtmlEncode ()
3. System.Xml.XmlTextWriter

I could explain every case, but I found this link very useful .