Add namespace to XAML code

I'm 开发者_开发知识库building an WPF (C#) application and I want to add a namespace to a XAML code (string type). I want to add the namespace on the correct place. Can anyone help me? Thanks, Peter.

EDIT:

It's a XAML code saved in a string like:

<UserControl x:Class="MyTestApp"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d".... 

I want to add a new namespace (like xmlns:test="http://www.test.nl") on the correct place.

As you have the XAML in one string, and presumably you have a second string containing the new namespace declaration, it seems that you simply need to use string.Insert to place it in. Your code would be as simple as this:

string xamlString = "... get some xaml from somewhere ...";
int insertPosition = xamlString.IndexOf(">");
xamlString.Insert(insertPosition, "my new namespace");

So I just get the index of the first closing angle bracket, and insert the new namespace right there.