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Wie werden Daten aus der Datenbank in das Textfeld angezeigt und aktualisiert?

Ich kann meine Daten in meiner Textbox anzeigen, Dropdown-Liste nach dem Abrufen von Daten aus der SQL-Datenbank. Wenn ich jedoch mit meiner Aktualisierungsschaltfläche fortgefahren bin, werden die in der Textbox oder Dropdown-Liste bearbeiteten Informationen nicht in der Datenbank aktualisiert. Ich habe versucht, den Code beim Laden der Seite zu entfernen und alle Daten manuell neu einzugeben. Es kann aktualisiert werden. Alles was ich möchte ist, Daten von der Datenbank abzurufen und sie in der Textbox anzuzeigen, und es kann in der Datenbank aktualisiert werden, nachdem einige Änderungen in der Textbox vorgenommen wurden. Kann mir da jemand weiterhelfen? Vielen Dank.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;
using System.Data;
public partial class UpdateCustomerDetails : System.Web.UI.Page
{

protected void Page_Load(object sender, EventArgs e)
{
    SqlConnection con1 = new SqlConnection("Data Source=USER-PC;Initial Catalog=webservice_database;Integrated Security=True");
    DataTable dt = new DataTable();
    con1.Open();
    SqlDataReader myReader = null;  
    SqlCommand myCommand = new SqlCommand("select * from customer_registration where username='" + Session["username"] + "'", con1);

    myReader = myCommand.ExecuteReader();

    while (myReader.Read())
    {
        TextBoxPassword.Text = (myReader["password"].ToString());
        TextBoxRPassword.Text = (myReader["retypepassword"].ToString());
        DropDownListGender.SelectedItem.Text = (myReader["gender"].ToString());
        DropDownListMonth.Text = (myReader["birth"].ToString());
        DropDownListYear.Text = (myReader["birth"].ToString());
        TextBoxAddress.Text = (myReader["address"].ToString());
        TextBoxCity.Text = (myReader["city"].ToString());
        DropDownListCountry.SelectedItem.Text = (myReader["country"].ToString());
        TextBoxPostcode.Text = (myReader["postcode"].ToString());
        TextBoxEmail.Text = (myReader["email"].ToString());
        TextBoxCarno.Text = (myReader["carno"].ToString());
    }
    con1.Close();
}
protected void Button1_Click(object sender, EventArgs e)
{
    SqlConnection con = new SqlConnection("Data Source=USER-PC;Initial Catalog=webservice_database;Integrated Security=True");
    SqlCommand cmd = new SqlCommand("UPDATE customer_registration SET password = @password, retypepassword = @retypepassword, gender = @gender, birth = @birth, address = @address, city = @city, country = @country, postcode = @postcode, email = @email, carno = @carno where username='" + Session["username"] + "'", con);
    con.Open();

    cmd.Parameters.AddWithValue("@password", TextBoxPassword.Text);
    cmd.Parameters.AddWithValue("@retypepassword", TextBoxRPassword.Text);
    cmd.Parameters.AddWithValue("@gender", DropDownListGender.Text);
    cmd.Parameters.AddWithValue("@birth", DropDownListDay.Text + DropDownListMonth.Text + DropDownListYear.Text);
    cmd.Parameters.AddWithValue("@address", TextBoxAddress.Text);
    cmd.Parameters.AddWithValue("@city", TextBoxCity.Text);
    cmd.Parameters.AddWithValue("@country", DropDownListCountry.Text);
    cmd.Parameters.AddWithValue("@postcode", TextBoxPostcode.Text);
    cmd.Parameters.AddWithValue("@email", TextBoxEmail.Text);
    cmd.Parameters.AddWithValue("@carno", TextBoxCarno.Text);

    cmd.ExecuteNonQuery();
    con.Close();
    if (IsPostBack)
    {
        Response.Redirect("UpdateSuccess.aspx");
    }
}
4
Ching

Wickeln Sie alle Anweisungen in !IsPostBack-Bedingung beim Laden der Seite ein.

protected void Page_Load(object sender, EventArgs e)
{
   if(!IsPostBack)
   {
      // all statements
   }
}

Dies wird Ihr Problem beheben.

protected void Page_Load(object sender, EventArgs e)

    {

        DropDownTitle();
    }


protected void DropDownTitle()
{
    if (!Page.IsPostBack)
    {

        string connection = System.Configuration.ConfigurationManager.ConnectionStrings["AuzineConnection"].ConnectionString;

        string selectSQL = "select DISTINCT ForumTitlesID,ForumTitles from ForumTtitle";
        SqlConnection con = new SqlConnection(connection);
        SqlCommand cmd = new SqlCommand(selectSQL, con);
        SqlDataReader reader;
        try
        {

            ListItem newItem = new ListItem();
            newItem.Text = "Select";
            newItem.Value = "0";
            ForumTitleList.Items.Add(newItem);
            con.Open();
            reader = cmd.ExecuteReader();



            while (reader.Read())
            {
                ListItem newItem1 = new ListItem();
                newItem1.Text = reader["ForumTitles"].ToString();
                newItem1.Value = reader["ForumTitlesID"].ToString();
                ForumTitleList.Items.Add(newItem1);



            }
            reader.Close();
            reader.Dispose();
            con.Close();
            con.Dispose();
            cmd.Dispose();


        }
        catch (Exception ex)
        {
            Response.Write(ex.Message);
        }

    }
}
1

Die Antwort lautet .IsPostBack, wie von @Kundan Singh Chouhan vorgeschlagen. Um es hinzuzufügen, verschieben Sie Ihren Code in eine separate Methode von PageLoad

private void PopulateFields()
{
  using(SqlConnection con1 = new SqlConnection("Data Source=USER-PC;Initial Catalog=webservice_database;Integrated Security=True"))
  {
    DataTable dt = new DataTable();
    con1.Open();
    SqlDataReader myReader = null;  
    SqlCommand myCommand = new SqlCommand("select * from customer_registration where username='" + Session["username"] + "'", con1);

    myReader = myCommand.ExecuteReader();

    while (myReader.Read())
    {
        TextBoxPassword.Text = (myReader["password"].ToString());
        TextBoxRPassword.Text = (myReader["retypepassword"].ToString());
        DropDownListGender.SelectedItem.Text = (myReader["gender"].ToString());
        DropDownListMonth.Text = (myReader["birth"].ToString());
        DropDownListYear.Text = (myReader["birth"].ToString());
        TextBoxAddress.Text = (myReader["address"].ToString());
        TextBoxCity.Text = (myReader["city"].ToString());
        DropDownListCountry.SelectedItem.Text = (myReader["country"].ToString());
        TextBoxPostcode.Text = (myReader["postcode"].ToString());
        TextBoxEmail.Text = (myReader["email"].ToString());
        TextBoxCarno.Text = (myReader["carno"].ToString());
    }
    con1.Close();
  }//end using
}

Dann rufen Sie es in Ihrem PageLoad auf

protected void Page_Load(object sender, EventArgs e)
{

    if(!Page.IsPostBack)
    {
       PopulateFields();
    }
}
0
codingbiz

Füllen Sie die Textfeldwerte im Page Init-Ereignis aus, anstatt Postback zu verwenden.

protected void Page_Init(object sender, EventArgs e)
{
    DropDownTitle();
}
0
John Wilson