Problem navigating database records to the next page in web form

Question

User53952362 posted

Hello All,

I am new to ASP.NET. I have encountered a problem in navigating the database records that is displayed in the web form , the Next and Previous buttons. I have 4 imageboxes and 2 textboxes under each image box for displaying database records.

I am currently using an Access database with a table "Images" and there are 4 columns in it. "ImageID", "ImageDescription","ImageofPicture","Description".

My Code is below:

   OleDbDataAdapter daImage = default(OleDbDataAdapter);
    DataSet dsImage = null;
    int MaxRows = 0;
    int inc = 0;
    int inc1 = 1;
    int inc2 = 2;
    int inc3 = 3;
    System.Data.OleDb.OleDbConnection cs;
    System.Data.OleDb.OleDbDataAdapter dta;
    DataSet ds1;
    MemoryStream ms;
    byte[] photo_array;

 

  protected void Page_Load(object sender, EventArgs e)
    {

        cs = new System.Data.OleDb.OleDbConnection();
        //tell the program where the database is located
        cs.ConnectionString = "Provider=Microsoft.Jet.OleDb.4.0;Data Source= C:\\Users\\Admin\\Desktop\\Website1\\App_Data\\Database.mdb";

        //create new dataset to store database records
        ds1 = new DataSet();

        string sql = "SELECT * From Images ORDER BY ImageDescription ASC";

        dta = new System.Data.OleDb.OleDbDataAdapter(sql, cs);
        cs.Open();

        //Fill the records from the database to dataset
        dta.Fill(ds1, "Images");

            NavigateRecords();
        //MaxRows equals to the total amount of records from the database
        MaxRows = ds1.Tables["Images"].Rows.Count;

    }

private void NavigateRecords()
    {
        //get the first record
        DataRow dtaRow = ds1.Tables["Images"].Rows[inc];
        //get column values in the row
        TextBox3.Text = dtaRow.ItemArray.GetValue(1).ToString();
        TextBox7.Text = dtaRow.ItemArray.GetValue(3).ToString();
        
        //get the second record
        DataRow dtaRow1 = ds1.Tables["Images"].Rows[inc1];
        TextBox4.Text = dtaRow1.ItemArray.GetValue(1).ToString();
        TextBox2.Text = dtaRow1.ItemArray.GetValue(3).ToString();
        
        //get the third record
        DataRow dtaRow2 = ds1.Tables["Images"].Rows[inc2];
        TextBox5.Text = dtaRow2.ItemArray.GetValue(1).ToString();
        TextBox8.Text = dtaRow2.ItemArray.GetValue(3).ToString();
        

        //get the fourth record
        DataRow dtaRow3 = ds1.Tables["Images"].Rows[inc3];
        TextBox6.Text = dtaRow3.ItemArray.GetValue(1).ToString();
        TextBox9.Text = dtaRow3.ItemArray.GetValue(3).ToString();
        

        //if 3rd column value is not null
        if (ds1.Tables[0].Rows[inc][2] != System.DBNull.Value)
        {

            Image2.ImageUrl = "ImageHandler.ashx?ImageDescription=" + TextBox3.Text;
        }


        if (ds1.Tables[0].Rows[inc1][2] != System.DBNull.Value)
        {
            Image3.ImageUrl = "ImageHandler.ashx?ImageDescription=" + TextBox4.Text;
        }

        if (ds1.Tables[0].Rows[inc2][2] != System.DBNull.Value)
        {
            Image4.ImageUrl = "ImageHandler.ashx?ImageDescription=" + TextBox5.Text;
        }

        if (ds1.Tables[0].Rows[inc3][2] != System.DBNull.Value)
        {
            Image5.ImageUrl = "ImageHandler.ashx?ImageDescription=" + TextBox6.Text;
        }

        
    }

 protected void nextBtn_Click(object sender, EventArgs e)
    {

        if (inc + 4 <= MaxRows - 1)
        {
            inc = inc + 4;
            NavigateRecords();
        }



        if (inc1 + 4 <= MaxRows - 1)
        {
            inc1 = inc1 + 4;
            NavigateRecords();
        }
        else
        {
            Image2.ImageUrl = null;
            TextBox4.Text = null;
            TextBox2.Text = null;


        }



        if (inc2 + 4 <= MaxRows - 1)
        {
            inc2 = inc2 + 4;
            NavigateRecords();
        }
        else
        {
            Image3.ImageUrl = null;
            TextBox5.Text = null;
            TextBox8.Text = null;

        }

                if (inc3 + 4 <= MaxRows - 1)
                {
                    inc3 = inc3 + 4;
                    NavigateRecords();
                }
                else
                {
                    pictureBox4.Image.Dispose();
                    pictureBox4.Image = null;
                    textBox6.Text = null;
                    textBox9.Text = null;
                }

Answer 1

User759660354 posted

The problem lies probably in your Page_Load event.

You are always calling them even when there is a postback taking place.

that way you will always get the first page.

You should wrap that into somthing like

if(!this.IsPostBack)

{

NavigateRecords();

} 

Answer 2

User53952362 posted

Hi fdepijper,

Thanks for replying. I have wrapped the NavigateRecords but it can only navigate to the 2nd page of the records at the most. Meaning that i can only view up to 8 records when there are a lot more records in the database with the next button. Which means the next button only work once.

 

Regards
DreamLive