Was quoting "application set", but code was not seen in the background.

[Starry]

Question  One  :  Was quoting "application set", but code was not seen in the background.   Why???

No  way to  "using".   XAML  front, xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation" ,No  Prolem...

Question two: "XMLNS: telerik =" http://schemas.telerik.com/2008/xaml/presentation "" after quote,        backstage" using telerik. Windows. Controls. The Docking;" It wrong.       Seem "XAML" front end quote ,  ". Cs    using "washed-up.   why???

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Telerik.Windows.Controls.Docking;
namespace SLTelerikRadDocking
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();
        }
    }

 错误 31 未能找到类型或命名空间名称“Telerik”(是否缺少 using 指令或程序集引用?) C:\Users\Administrator\Desktop\Test\SLTelerikRadDocking\SLTelerikRadDocking\MainPage.xaml.cs 12 7  SLTelerikRadDocking

}


Picture as below: