Paging in nested gridview webforms

Question

I am having a little trouble with paging in a nested grid view. When I try to change page I am getting some very strange and unexpected behaviour. Sometimes it will post back but not actually change the page and sometimes it does change the page but not as expected, it is messing with the order so you will have some items from the previous page still.

My markup is as follows:


            


    

        
            
                
            
            
                
                    Select a product

My code behind:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Globalization;
using System.IO;
using System.Data;
using System.Data.SqlTypes;
using System.Data.SqlClient;
using System.Web.Configuration;

public partial class Admin_ProductManagement_addProdImage : System.Web.UI.Page
{
private string connectionString =
   WebConfigurationManager.ConnectionStrings["bncConn"].ConnectionString;

private string imageDirectory;

protected void Page_Load(object sender, EventArgs e)
{

    // ensure images are uploaded to the right folder.
    imageDirectory = Path.Combine(
        Request.PhysicalApplicationPath, @"Images\ProductImages");

    if (!this.IsPostBack)
    {
        BindGrid();
    }
}
protected void BindGrid()
{
    // define ado.net objects.       
    SqlConnection con = new SqlConnection(connectionString);
    SqlCommand cmd = new SqlCommand("ProductDetails.bnc_ProductImages", con);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    // define sp parameters
    cmd.Parameters.Add(new SqlParameter("@Status", SqlDbType.VarChar, 50));
    cmd.Parameters["@Status"].Value = "DisplayMain";

    try
    {
        con.Open(); // try to open the connection
        DataSet ds = new DataSet(); // Initializes a new instance of the DataSet class
        adapter.Fill(ds, "ProductImages"); // Adds or refreshes rows in the DataSet to match those in the data source using the DataSet and DataTable names
        grdImages.DataSource = ds;  // sets the gridview datasource
        grdImages.DataBind();       // binds data to gridview
        // find dropdownlist in the footer row of the gridview
        DropDownList prods = (DropDownList)grdImages.FooterRow.FindControl("lstAddProdId");
        // call function
        lstProducts(prods);
    }
    catch (Exception err)
    {
        lblGrdImages.Text = "BindGrid error: " + err.Message + err.Source + err.StackTrace;    // display exceptions in label
    }
    finally
    {
        con.Close();    // close connection, even if action was unsuccessful.
    }
}

protected void BindNestedGrid(int product, GridView grd)
{

    // define ado.net objects.
    SqlConnection con = new SqlConnection(connectionString);
    SqlCommand cmd = new SqlCommand("ProductDetails.bnc_ProductImages", con);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataAdapter adapt = new SqlDataAdapter(cmd);
    // define sp parameters
    cmd.Parameters.Add(new SqlParameter("@Status", SqlDbType.VarChar, 50));
    cmd.Parameters["@Status"].Value = "DisplayExtra";
    cmd.Parameters.Add(new SqlParameter("@ProductId", SqlDbType.Int));
    cmd.Parameters["@ProductId"].Value = product;
    // try to connect, fill dataset and close connection. Also catch exceptions.
    try
    {
        con.Open(); // open the connection.
        DataSet rds = new DataSet();    // initialize a data set.
        adapt.Fill(rds, "ExtraImages"); // fills dataset
        grd.DataSource = rds;   // assign data source.
        grd.DataBind();     // bind data.
    }
    catch (Exception err)
    {
        lblGrdImages.Text = "Bind Nested Grid Error: " + err.Message;        // catch exceptions.

    }
    finally
    {
        con.Close(); // close the db connection
    }
}

protected void lstProducts(DropDownList prods)
{

    // define ado.net objects
    SqlConnection con = new SqlConnection(connectionString);
    SqlCommand cmd = new SqlCommand("ProductDetails.bnc_ProductImages", con);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataReader reader;
    // define the sp parameters
    cmd.Parameters.Add(new SqlParameter("@Status", SqlDbType.VarChar, 50));
    cmd.Parameters["@Status"].Value = "LstProds";

    try
    {
        con.Open(); // try to connect to db.
        reader = cmd.ExecuteReader();   // execut the reader
        while (reader.Read())
        {                
            ListItem item = new ListItem(); // create listitem
            item.Text = reader["ProductName"].ToString();   // add product name to item text
            item.Value = reader["ProductId"].ToString();    // add productId to item value
            prods.Items.Add(item);    // populate dropdown list.
        }

    }
    catch (Exception err)
    {
        lblGrdImages.Text = "List Products Error: " + err.Message; // display error message in  a label
    }
    finally
    {
        con.Close();    // close the connection.
    }
}
protected void addMain(int ProdId, string ImgName, string ImgPath)
{
    // define ado.net objects
    SqlConnection con = new SqlConnection(connectionString);
    SqlCommand cmd = new SqlCommand("ProductDetails.bnc_ProductImages", con);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    // define sp parameters
    cmd.Parameters.Add(new SqlParameter("@Status", SqlDbType.VarChar, 50));
    cmd.Parameters["@Status"].Value = "AddMain";
    cmd.Parameters.Add(new SqlParameter("@ImageName", SqlDbType.VarChar, 50));
    cmd.Parameters["@ImageName"].Value = ImgName;
    cmd.Parameters.Add(new SqlParameter("@ImagePath", SqlDbType.VarChar, -1));
    cmd.Parameters["@ImagePath"].Value = ImgPath;
    cmd.Parameters.Add(new SqlParameter("@ProductId", SqlDbType.Int));
    cmd.Parameters["@ProductId"].Value = ProdId;

    try
    {
        con.Open(); // attempt to open the connection
        DataSet ds = new DataSet(); // initialize the dataset
        adapter.Fill(ds, "ProductImages");  // fill the data set.           
    }
    catch (Exception err)
    {
        lblGrdImages.Text = "Add main error: " + err.Message;    // display exceptions in a label control
    }
    finally
    {
        con.Close();    // close connection.
    }
}
protected void addExtraImages(int ProductId, string ExImgName, string ExImagePath)
{
    // define ado.net objects
    SqlConnection con = new SqlConnection(connectionString);
    SqlCommand cmd = new SqlCommand("ProductDetails.bnc_ProductImages", con);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    // define sp parameters
    cmd.Parameters.Add(new SqlParameter("@Status", SqlDbType.VarChar, 50));
    cmd.Parameters["@Status"].Value = "AddExtra";
    cmd.Parameters.Add(new SqlParameter("@ProductId", SqlDbType.Int));
    cmd.Parameters["@ProductId"].Value = ProductId;
    cmd.Parameters.Add(new SqlParameter("@ImageName", SqlDbType.VarChar,50));
    cmd.Parameters["@ImageName"].Value = ExImgName;
    cmd.Parameters.Add(new SqlParameter("@ImagePath", SqlDbType.VarChar,-1));
    cmd.Parameters["@ImagePath"].Value = ExImagePath;

    try
    {
        con.Open(); // try to open db connection
        DataSet ds = new DataSet(); // initialize data set.
        adapter.Fill(ds, "ProductImages"); // fill the data set.
    }
    catch (Exception err)
    {
        lblGrdImages.Text = "Add extra images error: " + err.Message;    // display exception in a label
    }
    finally
    {
        con.Close();    // close the connection
    }
}
protected void DeleteProductImages(int Product)
{
    // define ado.net objects
    SqlConnection con = new SqlConnection(connectionString);
    SqlCommand cmd = new SqlCommand("ProductDetails.bnc_ProductImages", con);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    // define sp parameters
    cmd.Parameters.Add(new SqlParameter("@Status", SqlDbType.VarChar, 50));
    cmd.Parameters["@Status"].Value = "Delete";
    cmd.Parameters.Add(new SqlParameter("@ProductId", SqlDbType.Int));
    cmd.Parameters["@ProductId"].Value = Product;

    try
    {
        con.Open(); // open connection
        DataSet ds = new DataSet(); // initialize rthe dataset
        adapter.Fill(ds);   // fill dataset.
    }
    catch (Exception err)
    {
        lblGrdImages.Text = "Delete error:  " + err.Message;        // report error in a label.
    }
    finally
    {
        con.Close();    // close the connection.
    }
}
protected void grdImages_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    grdImages.PageIndex = e.NewPageIndex;      // sets the page index
    BindGrid();     // bind the grid.
}
protected void grdImages_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
    grdImages.EditIndex = -1;   // sets the page index
    BindGrid();         // bind the grid.
}
private bool isValid(HttpPostedFile file, string[] extAry, string ext) // checks extension
{
    bool isValid = false;
    for (int i = 0; i < extAry.Length; i++)
    {
        if (ext.ToLowerInvariant().IndexOf(extAry[i]) > -1)

            isValid = true;

    }
    return isValid;

}
protected void uploadMainImage() {
    string[] validFileTypes = { ".jpg", ".png" };   // file type array
    FileUpload main = (FileUpload)grdImages.FooterRow.FindControl("flupMain");  // find control
    DropDownList products = (DropDownList)grdImages.FooterRow.FindControl("lstAddProdId");  // find control
    string mainFile = Path.GetFileName(main.PostedFile.FileName);                // get file name.
            string ext = Path.GetExtension(mainFile);       // get file extension.
            if (isValid(main.PostedFile, validFileTypes, ext))  // check if file extension is valid.
            {
                if (File.Exists(mainFile))  // check if file exists
                {
                    lblGrdImages.Text = "File with the name: " + mainFile + " already exists. Please rename or choose a different file.";
                }
                else
                {

                    try
                    {
                        string serverFileName = Path.GetFileName(mainFile); // assign values to variables
                        string uploadPath = Path.Combine(imageDirectory, serverFileName);
                        int Product = Convert.ToInt32(products.SelectedValue);
                        main.SaveAs(uploadPath);    // save file
                        addMain(Product, serverFileName, @"~\Images\ProductImages\" + serverFileName);   // Call stored procedure
                    }
                    catch (Exception err)
                    {
                        lblGrdImages.Text = err.Message;
                    }

                }
}
}
protected void uploadExtraImages()
{
    string[] validFileTypes = { ".jpg", ".png" };   // file type array
    FileUpload extra = (FileUpload)grdImages.FooterRow.FindControl("flupExtra");    // find conrol
    DropDownList products = (DropDownList)grdImages.FooterRow.FindControl("lstAddProdId");  // find control
    if (extra.HasFiles)
    {
        foreach (HttpPostedFile file in extra.PostedFiles)
        {
            string ext = Path.GetExtension(file.FileName);
            if (isValid(file, validFileTypes, ext))  // check file extension
            {
                string serverFileName = Path.GetFileName(file.FileName); // assign values to variables
                string uploadPath = Path.Combine(imageDirectory, serverFileName);
                int Product = Convert.ToInt32(products.SelectedValue);
                try
                {
                    file.SaveAs(uploadPath); // save file
                    addExtraImages(Product, serverFileName, @"~\Images\ProductImages\" + serverFileName);  // call stored procedure
                }
                catch (Exception err)
                {
                    lblGrdImages.Text = "Error: " + err.Message;
                }

            }
        }
    }
}
protected void grdImages_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName.Equals("Add"))
    {
        // find the required controls in the grdview.            
        FileUpload main = (FileUpload)grdImages.FooterRow.FindControl("flupMain");
        FileUpload extra = (FileUpload)grdImages.FooterRow.FindControl("flupExtra");

        if (main.HasFile)
        {
            uploadMainImage();
            if (extra.HasFiles)
            {
                uploadExtraImages();
            }

            grdImages.EditIndex = -1;
        BindGrid();

        }
        else 
        {
            lblGrdImages.Text = "Product main image is required.";
        }

    }
}
protected void grdImages_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (!this.IsPostBack)
    {      

        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            GridView grd = (GridView)e.Row.FindControl("grdSupImages"); // find controls
            Label prodId = (Label)e.Row.FindControl("lblProdId");
            int product = Convert.ToInt32(prodId.Text);        // assign values to variables.
            BindNestedGrid(product, grd);      // call the function.
        }
     }
}


protected void grdImages_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
    //  find controls
    Label product = (Label)grdImages.Rows[e.RowIndex].FindControl("lblProdId");
    Label image = (Label)grdImages.Rows[e.RowIndex].FindControl("lblMainImgName");
    GridView grd = (GridView)grdImages.Rows[e.RowIndex].FindControl("grdSupImages");
    // declare variables and assign values
    int prodid = Convert.ToInt32(product.Text);
    string path = Server.MapPath(@"~\Images\ProductImages\" + image.Text);
    File.Delete(path);
    foreach(GridViewRow row in grd.Rows)
    {
        Label img = (Label)row.FindControl("imgSupName");
        string imgName = img.Text;
        string imgPath = Server.MapPath(@"~\Images\ProductImages\" + imgName);
        try
        {
            File.Delete(imgPath);

        }
        catch (Exception err)
        {
            lblGrdImages.Text = "File Delete Error:  " + err.Message + "
" + err.InnerException + "||" + err.StackTrace;
        }
    }
    DeleteProductImages(prodid);
    grdImages.EditIndex = -1;
    BindGrid();
}



protected void grdImages_RowEditing(object sender, GridViewEditEventArgs e)
{
    grdImages.EditIndex = e.NewEditIndex;

    BindGrid();
}
protected void grdImages_RowUpdating(object sender, GridViewUpdateEventArgs e)
{

}
protected void grdSupImages_RowEditing(object sender, GridViewEditEventArgs e)
{

}
protected void grdSupImages_RowUpdating(object sender, GridViewUpdateEventArgs e)
{

}
protected void grdSupImages_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView gv = (GridView)sender;
    gv.PageIndex = e.NewPageIndex;



}
}

I would be eternally grateful of any assistance with this matter. If you require any further information please let me know and I will provide.

M_Griffiths · Accepted Answer

Although nobody wanted to help me, I have found the answer to my problem. I thought id share this information as it may be able to help somebody else.

This is what I came up with for my child gridview pageindexchanging event:

protected void grdSupImages_PageIndexChanging(object sender, GridViewPageEventArgs e)
{

    GridView gv = (GridView)sender;               
    gv.PageIndex = e.NewPageIndex;        
    BindNestedGrid(Convert.ToInt32(gv.ToolTip), gv);


}

Paging in nested gridview webforms

Answers (1)

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