Question

我是ASP.NET C＃的新手，我必须在学校做点什么。我必须做电子商店。简单的事情，但我用桌子做。我正在生成表，但最后一个单元依赖于用户登录。如果您尚未登录，则只有文本。当你在，在最后一个单元格中有一个名为“index”的文本框和名为“koupit”的按钮。当我点击按钮时，它会将我引导到页面，SQL代码在哪里。该代码意味着，我可以购买我选择的项目。一切都很好。我只对事件处理程序有问题。它需要一些回报，但我不知道它想要什么。

有我的代码：

namespace e_shop
{
    public partial class index1 : System.Web.UI.Page
    {
        string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["eshop"].ToString();

         string id_item;

      // label, where I will write, that there is some problem            
            private string error = "";
        private void Page_Load(object sender, EventArgs e)
        {
            {
                //connect to DB
                //connection string

                //sql connect
                SqlConnection sqlConnection = new SqlConnection(connectionString);
                //buttons
                if (Request.Form["puj_prihl"] != null)
                {
                    //someone click on log in
                    string login = Request.Form["puj_login"];
                    string password = Request.Form["puj_password"];
                    //delete white-spaces
                    login = login.Trim();
                    password = password.Trim();
                    //controll on null
                    if (login.Equals("") || password.Equals(""))
                    {
                        error = "You have to write something";
                    }
                    else
                    {

                        //try to log in
                        if (Function.userLogin(login, password, sqlConnection))
                        {
                            //you are logged in
                        }
                        else
                        {
                            //something is bad
                            error = "Something is bad";
                        }
                    }
                }
                if (Request.Form["puj_odhl"] != null)
                {
                    //someone click on logout button
                    if (!Function.userLogout())
                    {
                        error = "Something is bad";
                    }
                }
                //div-body
                //get everything about items
                SqlCommand sqlCommand = new SqlCommand("SELECT * FROM [items]", sqlConnection);
                //Open connection
                sqlConnection.Open();
                //read everything
                SqlDataReader dataReader = sqlCommand.ExecuteReader();
                //read rows
                while (dataReader.Read())
                {
                    //new row
                    TableRow tr = new TableRow();
                    //I need id id
                     id_item = dataReader["ID_item"].ToString();
                    //next cells
                    TableCell tc_name = new TableCell();
                    tc_name.Text = dataReader["name_item"].ToString();
                    TableCell tc_popis = new TableCell();
                    tc_popis.Text = dataReader["popis_item"].ToString();
                    TableCell tc_category = new TableCell();
                    tc_category.Text = dataReader["category_item"].ToString();
                    TableCell tc_price = new TableCell();
                    tc_price.Text = dataReader["price_item"].ToString();
                    //cell for click
                    TableCell tc_click = new TableCell();
                    if (!Funkce.isLoggedIn())
                    {
                        //user isnt logged
                        tc_click.Text = "You have to log in";
                    }
                    else
                    {

                        Button buy = new Button();
                        buy.Text = "Buy";

                       TextBox index = new TextBox();

                        tc_click.Controls.Add(buy);
                        tc_click.Controls.Add(index);
                        buy.Click+= buy_Click(index, id_item);

                        }



                    //cells to row
                    tr.Cells.Add(tc_name);
                    tr.Cells.Add(tc_popis);
                    tr.Cells.Add(tc_category);
                    tr.Cells.Add(tc_price);
                    tr.Cells.Add(tc_click);

                    //row to table
                    table_eshop.Rows.Add(tr);
                }
                //close reader
                dataReader.Close();
                //close connection
                sqlConnection.Close();
                //div-login
                literal_login.Text = "<form action=\"\" method=\"post\">\n";
                if (Funkce.isLoggedIn())
                {

                    //if we are logged in we need logout form
                    literal_login.Text += "<input type=\"submit\" name=\"puj_odhl\" value=\"Logout\" />\n";
                    label_who.Text = "<p>Logged user: " + Function.getUserLogin(Session[Session.SessionID].ToString(), sqlConnection) + " </p>\n";
                    my_cart.Visible = true;
                }
                else
                {
                    //else we need to logg in
                    literal_login.Text += "Login: <input type=\"text\" name=\"puj_login\" /><br />\n";
                    literal_login.Text += "Password: <input type=\"password\" name=\"puj_password\" /><br />\n";
                    literal_login.Text += "<input type=\"submit\" name=\"puj_prihl\" value=\"Logged in\" />\n";

                }
                literal_login.Text += "</form>\n";
                if (!chyba.Equals(""))
                {
                    label_error.Text = "<p class=\"error\"> " + error + " </p>";
                }

                  }
        }
                //here is problem
                   private EventHandler buy_Click(TextBox index, string id_item)
        {

            string quantity = index.Text;
       Response.Redirect("buy_it.aspx?id=" + id_item + "&quantity=" + quantity);

        }
            }
    }

Answer 1

在ASP.NET Web窗体中，如果您将hnd字符串作为html字符串，则按钮控件将无法触发服务器端单击事件。

//else we need to logg in
literal_login.Text += "Login: <input type=\"text\" name=\"puj_login\" /><br />\n";
literal_login.Text += "Password: <input type=\"password\" name=\"puj_password\" /><br />\n";
literal_login.Text += "<input type=\"submit\" name=\"puj_prihl\" value=\"Logged in\" />\n";

您需要使用服务器控件，并触发像这样的服务器端点击事件 -

<asp:TextBox runat="server" ID="UsernameTextBox" />
<asp:TextBox runat="server" ID="PasswordTextBox" />
<asp:Button runat="server" ID="SubmitButton" Text="Submit"
   OnClick="SubmitButton_Click" />

// Code Behind
protected void SubmitButton_Click(object sender, EventArgs e)
{
    string username = UsernameTextBox.Text,
        password = PasswordTextBox.Text;
    bool rememberMe = RememberMeCheckBox.Checked;

    // Retrieve username and hashed password from database, and validate them
    if (username.Equals("johndoe", StringComparison.InvariantCultureIgnoreCase) &&
        password.Equals("123456", StringComparison.InvariantCultureIgnoreCase))
    {
        FormsAuthentication.RedirectFromLoginPage(username, rememberMe);
    }
    MessageLabel.Text = "Invalid username or password";
}

我有a very simple ASP.NET Web Form Web Application at GitHub，它使用FormAuthentication。请随意克隆并测试它。

带参数的动态按钮和事件处理程序

1 个答案: