private void btnSave_Click(object sender, EventArgs e)
 {
     Button btn = sender as Button;
     if (btn != null)
     {
         try
         {
             btn.Enabled = false;
             Credentials cert = btn.Tag as Credentials;
             if (cert != null)
             {
                 CredentialsCollection data = new CredentialsCollection();
                 data.Add(cert);
                 CredentialsFactory.Serialize(data, FolderStructure.CredentialsFile);
                 this.CoreService["credentials"] = cert;
                 this.CoreService.AddForm(new LoginWindow(this.CoreService));
                 this.CoreService.ForceQuit = true;
                 this.Close();
             }
             else
             {
                 this.OnMessageEvent(MessageType.Normal | MessageType.PopupInfo, "请选择学校密钥!");
             }
         }
         catch (Exception ex)
         {
             this.OnMessageEvent(MessageType.Normal | MessageType.PopupWarn, "保存密钥时发生异常:" + ex.Message);
         }
         finally
         {
             btn.Enabled = true;
         }
     }
 }
 /// <summary>
 /// 构造函数。
 /// </summary>
 /// <param name="service">核心服务接口。</param>
 /// <param name="crets">密钥集合。</param>
 public SelectCredentialsWindow(ICoreService service, CredentialsCollection crets)
     : base(service)
 {
     this.crets = crets;
     InitializeComponent();
 }
 /// <summary>
 /// 
 /// </summary>
 public CredentialStore()
 {
     this.collection = new CredentialsCollection();
 }