Application["aa"]=bb;
TextBox1.Text=Application["aa"].ToString();
貌似Application不太好做你的那个东西
你加个类吧
class Chat{
 public User who;
 public string SayWhat;
 public DateTime SayTime;
 ....
 public Chat(User w,string sayWhat){
  this.who=w;
  this.sayWhat=sayWhat;
 }
}
class User{
  public string uid;
  private string pwd;
  public string name;
  public string info;
  public DateTime loginTime;
  ...//等等属性
  
public User(string u,string p){
  this.uid=u;
  this.pwd=p;
}
  public User(){
  }
  ...//构造器诺干 看你怎么用了
}
Application["谁的ID"]=new Chat(new User("123","123"),"说话");
TextBox1.Text=((Chat)Application["谁的ID"]).SayWhat;
                                           .你要输出的属性什么的
别抄啊, 手写的   没VS2005  思路而已