Rasmus Faber Rasmus Faber - 1 month ago 25
C# Question

Replace host in Uri

What is the nicest way of replacing the host-part of an Uri using .NET?

I.e.:

string ReplaceHost(string original, string newHostName);
//...
string s = ReplaceHost("http://oldhostname/index.html", "newhostname");
Assert.AreEqual("http://newhostname/index.html", s);
//...
string s = ReplaceHost("http://user:pass@oldhostname/index.html", "newhostname");
Assert.AreEqual("http://user:pass@newhostname/index.html", s);
//...
string s = ReplaceHost("ftp://user:pass@oldhostname", "newhostname");
Assert.AreEqual("ftp://user:pass@newhostname", s);
//etc.


System.Uri does not seem to help much.

Answer

System.UriBuilder is what you are after...

string ReplaceHost(string original, string newHostName) {
    var builder = new UriBuilder(original);
    builder.Host = newHostName;
    return builder.Uri.ToString();
}