我正在尝试创建一个类方法，该方法可选地返回该类的（已经实例化的）实例。
我正在考虑将实例化类的内存地址写入用户默认密钥，然后尝试返回该地址的对象，但我不确定这是否正确方法或如何做到这一点。
class MyClass {
let myProperty: String
required init(myProperty: String) {
self.myProperty = myProperty
}
class func currentClass() -> MyClass? {
return nil
}
}
let aNewClass = MyClass(myProperty: "Hi")
// Should return the aNewClass instance:
MyClass.currentClass()
答案 0 :(得分：3)
您需要创建一个静态属性，将已创建的成员分配给：
Results.aspx这有点类似于单例模式，您始终可以从类中检索相同的对象。您也可以删除作业周围的protected void Page_Load(object sender, EventArgs e)
{
if(!String.IsNullOrEmpty(Request.QueryString["srch"]))
{
String srch = Request.QueryString["srch"];
var myControl = (TextBox)Master.FindControl("search");
myControl.Text = srch;
//perform search and display results
String connString = System.Configuration.ConfigurationManager.ConnectionStrings["GroupsConnString"].ToString();
conn = new MySql.Data.MySqlClient.MySqlConnection(connString);
conn.Open();
queryStr = "";
queryStr = "SELECT g.*,CONCAT(firstname,' ',lastname) as name FROM app_groups.groups g LEFT JOIN users u ON u.id = g.id_user WHERE group_name LIKE '%" + srch + "%' OR group_type LIKE '%" + srch + "%'";
cmd = new MySql.Data.MySqlClient.MySqlCommand(queryStr, conn);
reader = cmd.ExecuteReader();
gname = "";//group name
gtype = "";//group type
uname = "";//user name
id = "";
warning = "";
id_owner = "";
if (reader.HasRows)
{
while (reader.HasRows && reader.Read())
{
uname = reader.GetString(reader.GetOrdinal("name"));
gname = reader.GetString(reader.GetOrdinal("group_name"));
gtype = reader.GetString(reader.GetOrdinal("group_type"));
id = reader.GetString(reader.GetOrdinal("id"));
id_owner = reader.GetString(reader.GetOrdinal("id_user"));
warning = reader.GetString(reader.GetOrdinal("warning"));
Panel pan = new Panel();
pan.CssClass = "col-sm-4";
Panel subpan = new Panel();
subpan.CssClass = "group";
if (Session["uid"] != null)
{
int sess_id = Convert.ToInt32(Session["uid"]);
if ((Session["uid"] != null && Session["uadmin"].Equals("1")) || sess_id.Equals(Int32.Parse(id_owner)))
{
adminCtrls = new Panel();
adminCtrls.CssClass = "adminCtrls";
btn = new Button();//delete group button for admins and owners only
btn.Click += new EventHandler(deleteGroup);
btn.ID = "sterge";
btn.CssClass = "btn btn-danger btn-xs";
btn.Text = "Sterge grup";
btn.CommandArgument = id;
//btn.Attributes.Add("style", "float:right;");
adminCtrls.Controls.Add(btn);
if (Session["uadmin"].Equals("1"))
{
if (!warning.Equals("1"))
{
btn = new Button();//warn owner button for admins only
btn.Click += new EventHandler(warnOwner);
btn.ID = "warn";
btn.CssClass = "btn btn-warning btn-xs";
btn.Text = "Avertizeaza owner grup";
btn.CommandArgument = id;
adminCtrls.Controls.Add(btn);
}
else
{
btn = new Button();//warn owner button for admins only
btn.ID = "warn";
btn.Enabled = false;
btn.CssClass = "btn btn-warning btn-xs";
btn.Text = "A fost avertizat";
adminCtrls.Controls.Add(btn);
}
}
}
else
{
adminCtrls = null;
}
if (adminCtrls != null)
{
subpan.Controls.Add(adminCtrls);
}
}
subpan.Controls.Add(new LiteralControl("<span class='title text-center'>" + gname + "</span><br/>"));
subpan.Controls.Add(new LiteralControl("<span>Owner: <span class='owner'>" + uname + "</span></span><br/>"));
subpan.Controls.Add(new LiteralControl("<span>Categorie: <span class='type'>" + gtype + "</span></span><br/>"));
pan.Controls.Add(subpan);
groupsShow.Controls.Add(pan);
}
}
reader.Close();
conn.Close();
}
}
，使Class始终返回最新的实例，如果最适合您的需要。