c# populate dropdownlist based on dropdownlist in gridview

Question

I have a gridview with it's own sqlDataSource. In the footer row, I have an Insert field to create a new row. However, that footer row is quite complex and I'm trying to figure out how to make it work.
What I would like to see happen, is that a user Selects the OTypeName ddl. Based on that selection, the OSpecies ddl is enabled and populates values based on the OTypeName ddl. The same can be said in relation to OSpecies and OVariety.

The user then inputs their own information into OAge, OYields, OPlantDate, and OPlantFrom.

The rest of the fields in the footer row are labels that will be populated based on the final OVariety selection.

The Insert button then adds all these columns to the gridview.

I only need help with populating one ddl based on the ddl selection of another and how to populate a label based on a ddl selection.

Here's my code in the aspx file:

</asp:TemplateField>

<asp:TemplateField HeaderText="OTypeName" SortExpression="OTypeName">

<asp:DropDownList ID="DropDownList1"

runat="server"

AutoPostBack="True"

DataSourceID="dsTypeName"

DataTextField="OrchardTypeName"

DataValueField="OrchardTypeID" >

</asp:DropDownList>

<asp:SqlDataSource ID="dsTypeName" runat="server" ConnectionString="<%$ ConnectionStrings:DB_9DE518_PermacultureConnectionString %>" SelectCommand="SELECT * FROM [tblOrchardType]"></asp:SqlDataSource>

</EditItemTemplate>

<asp:Label ID="Label2" runat="server" Text='<%# Bind("OTypeName") %>'></asp:Label>

</ItemTemplate>

<asp:DropDownList ID="ddlTypeName"

runat="server"

AutoPostBack="True"

DataSourceID="dsTypeName"

DataTextField="OrchardTypeName"

DataValueField="OrchardTypeID"

>

</asp:DropDownList>

<asp:SqlDataSource ID="dsTypeName" runat="server" ConnectionString="<%$ ConnectionStrings:DB_9DE518_PermacultureConnectionString %>" SelectCommand="SELECT * FROM [tblOrchardType]"></asp:SqlDataSource>

</FooterTemplate>

I'm not sure what to put in the aspx.cs file but here's what I have so far concerning the Index Change for the ddl:

public void ddlTypeName_SelectedIndexChanged(object sender, EventArgs e)

{

//Enable ddlSpecies

//Populate ddlSpecies based on ddlTypeName selection

var ddlTypeValue = ddlTypeName.SelectedValue;

}

Any help would be much appreciated!

Thomas Gaillard · Answer

Here is the code that I finally got to work: using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Data; using System.Data.SqlClient; using System.Configuration; using System.Web.Configuration; namespace PermacultureOrganizer { public partial class OrchardMainWebForm : System.Web.UI.Page { //Make the SQL connections SqlConnection con2 = new SqlConnection(@Data Source=SQL5018.SmarterASP.net;Initial Catalog=DB_9DE518_Permaculture;Persist Security Info=True;User ID=DB_9DE518_Permaculture_admin;Password=*****); public string con = WebConfigurationManager.ConnectionStrings[PermaCultureConnection].ConnectionString; public void Page_Load(object sender EventArgs e) { if (!IsPostBack) { //Create EventHandlers LinkButton btnInsert = new LinkButton(); btnInsert.Click += new EventHandler(btnInsert_Click); DropDownList ddlTypeName = new DropDownList(); ddlTypeName.SelectedIndexChanged += new EventHandler(ddlTypeName_SelectedIndexChanged); DropDownList ddlSpecies = new DropDownList(); ddlSpecies.SelectedIndexChanged += new EventHandler(ddlSpecies_SelectedIndexChanged); DropDownList ddlVariety = new DropDownList(); ddlVariety.SelectedIndexChanged += new EventHandler(ddlVariety_SelectedIndexChanged); } } protected void btnViewData_Click(object sender EventArgs e) { //Go to OrchardViewer Page Response.Redirect(OrchardViewer.aspx); } protected void btnSearchData_Click(object sender EventArgs e) { //Go to OrchardSearch Page Response.Redirect(OrchardSearch.aspx); } protected void ddlTypeName_SelectedIndexChanged(object sender EventArgs e) { //Populate ddlSpecies based on TypeName selection ddlSpecies.DataSource = RetrieveSpecies(ddlTypeName.SelectedValue); ddlSpecies.DataBind(); ddlSpecies.Items.Insert(0 Select Species); } private DataTable RetrieveSpecies(string OrchardTypeID) { //Use OrchardTypeID from TypeName selection to filter Species string connString = ConfigurationManager.ConnectionStrings[PermaCultureConnection].ConnectionString; string sql = @SELECT OrchardItemID OSpecies FROM tblOrchardItem WHERE OrchardTypeID =  + OrchardTypeID; DataTable dtSpecies = new DataTable(); using (SqlConnection conn = new SqlConnection(connString)) { conn.Open(); //Initialize command object using (SqlCommand cmd = new SqlCommand(sql conn)) { SqlDataAdapter adapter = new SqlDataAdapter(cmd); //Fill the result set adapter.Fill(dtSpecies); } } return dtSpecies; } protected void ddlSpecies_SelectedIndexChanged(object sender EventArgs e) { //Populate ddlVariety based on Species selection ddlVariety.DataSource = RetrieveVariety(ddlSpecies.SelectedValue); ddlVariety.DataBind(); ddlVariety.Items.Insert(0 Select Variety); } private DataTable RetrieveVariety(string OrchardItemID) { //Use OrchardTypeID from Species selection to filter Variety string connString = ConfigurationManager.ConnectionStrings[PermaCultureConnection].ConnectionString; string sql = @SELECT OrchardItemID OVariety FROM tblOrchardItem WHERE OrchardItemID =  + OrchardItemID; DataTable dtVariety = new DataTable(); using (SqlConnection conn = new SqlConnection(connString)) { conn.Open(); //Initialize command object using (SqlCommand cmd = new SqlCommand(sql conn)) { SqlDataAdapter adapter = new SqlDataAdapter(cmd); //Fill the result set adapter.Fill(dtVariety); } } return dtVariety; } protected void ddlVariety_SelectedIndexChanged(object sender EventArgs e) { //Gather additional data based on Variety selection int OrchardItemID = Convert.ToInt32(ddlVariety.SelectedIndex); BindOrchardGrid(OrchardItemID); //Display picture next based on Variety selection string Variety = ddlVariety.SelectedItem.ToString(); switch (Variety) { case Bladen: imageTree.ImageUrl = Images/blueberry-vine 300x200.jpg; break; case Bartlett: imageTree.ImageUrl = Images/Pear-Tree 300x200.jpg; break; case Babcook: imageTree.ImageUrl = Images/peach-tree-w-fruit 300x200.jpg; break; case Abbuoto: imageTree.ImageUrl = Images/grape-vine 300x200.jpg; break; case Carya: imageTree.ImageUrl = Images/pecans 300x200.jpg; break; } } private void BindOrchardGrid(int OrchardItemID) { DataSet dtLabels; SqlDataAdapter sda = new SqlDataAdapter(); SqlCommand cmd = new SqlCommand(SELECT * FROM tblOrchardItem WHERE OrchardItemID =  + OrchardItemID con2); sda.SelectCommand = cmd; dtLabels = new DataSet(OrchardItem); sda.Fill(dtLabels OrchardItem); foreach (DataRow row in dtLabels.Tables[OrchardItem].Rows) { //Gather other pertinent data based on Variety selected lblTreeSpacing.Text = Convert.ToString(row[OTreeSpacing]); lblFertilizingTimes.Text = Convert.ToString(row[OFertilizingTimes]); lblPruningTimes.Text = Convert.ToString(row[OPruningTimes]); lblWateringNeeds.Text = Convert.ToString(row[OWateringNeeds]); lblPollination.Text = Convert.ToString(row[OPollination]); int FertilizerID = Convert.ToInt32(row[FertilizerID]); int PesticideID = Convert.ToInt32(row[PesticideID]); DataSet dtFert; SqlDataAdapter sdaF = new SqlDataAdapter(); SqlCommand cmdF = new SqlCommand(SELECT * FROM tblFertilizer WHERE FertilizerID =  + FertilizerID con2); sdaF.SelectCommand = cmdF; dtFert = new DataSet(Fert); sdaF.Fill(dtFert Fert); foreach (DataRow rowF in dtFert.Tables[Fert].Rows) { lblFertilizer.Text = Convert.ToString(rowF[FertilizerName]); } DataSet dtPest; SqlDataAdapter sdaP = new SqlDataAdapter(); SqlCommand cmdP = new SqlCommand(SELECT * FROM tblPesticide WHERE PesticideID =  + PesticideID con2); sdaP.SelectCommand = cmdP; dtPest = new DataSet(Pest); sdaP.Fill(dtPest Pest); foreach (DataRow rowP in dtPest.Tables[Pest].Rows) { lblPesticide.Text = Convert.ToString(rowP[PesticideName]); } } } public void btnInsert_Click(object sender EventArgs e) { //After the user inputs data insert it into the database and then switch to OrchardViewer page CreateOrchard(con); Response.Redirect(OrchardViewer.aspx); } public DataTable CreateOrchard(string con) { DataTable dtOrchard = new DataTable(); using (SqlConnection Connection = new SqlConnection(con)) { SqlCommand sqlcmd = new SqlCommand(); //associate command object with connection sqlcmd.Connection = Connection; sqlcmd.CommandType = CommandType.StoredProcedure; sqlcmd.CommandText = spInsertOrchardData; //Gather user input for insert into database sqlcmd.Parameters.Add(@UserOrchardID SqlDbType.VarChar 1000).Value = ; sqlcmd.Parameters.Add(@TypeName SqlDbType.VarChar 1000).Value = Convert.ToString(ddlTypeName.SelectedItem); sqlcmd.Parameters.Add(@Species SqlDbType.VarChar 1000).Value = Convert.ToString(ddlSpecies.SelectedItem); sqlcmd.Parameters.Add(@Variety SqlDbType.VarChar 1000).Value = Convert.ToString(ddlVariety.SelectedItem); sqlcmd.Parameters.Add(@Age SqlDbType.Int 1000).Value = Convert.ToInt32(txtBxAge.Text); sqlcmd.Parameters.Add(@Yields SqlDbType.VarChar 1000).Value = Convert.ToInt32(txtBxYields.Text); sqlcmd.Parameters.Add(@PlantDate SqlDbType.VarChar 1000).Value = Convert.ToString(txtBxPlantDate.Text); sqlcmd.Parameters.Add(@PlantFrom SqlDbType.VarChar 1000).Value = Convert.ToString(txtBxPlantFrom.Text); sqlcmd.Parameters.Add(@TreeSpacing SqlDbType.VarChar 1000).Value = Convert.ToString(lblTreeSpacing.Text); sqlcmd.Parameters.Add(@FertilizingTimes SqlDbType.VarChar 1000).Value = Convert.ToString(lblFertilizingTimes.Text); sqlcmd.Parameters.Add(@PruningTimes SqlDbType.VarChar 1000).Value = Convert.ToString(lblPruningTimes.Text); sqlcmd.Parameters.Add(@WateringNeeds SqlDbType.VarChar 1000).Value = Convert.ToString(lblWateringNeeds.Text); sqlcmd.Parameters.Add(@Pollination SqlDbType.VarChar 1000).Value = Convert.ToString(lblPollination.Text); sqlcmd.Parameters.Add(@Fertilizer SqlDbType.VarChar 1000).Value = Convert.ToString(lblFertilizer.Text); sqlcmd.Parameters.Add(@Pesticide SqlDbType.VarChar 1000).Value = Convert.ToString(lblPesticide.Text); using (SqlDataAdapter sda = new SqlDataAdapter(sqlcmd)) { DataSet dataset = new DataSet(); sda.Fill(dataset); } } return dtOrchard; } } }

Chandu Kumawat · Answer

hi... refer this http://www.aspsnippets.com/Articles/Creating-Cascading-DropDownLists-in-ASP.Net.aspx https://aspdotnetcodehelp.wordpress.com/2015/04/15/how-to-create-cascading-dropdown-list-in-asp-net/

Munesh Sharma · Answer

http://technico.qnownow.com/how-to-populate-dropdownlist-based-on-another-dropdownlist-inside-a-gridview/

Munesh Sharma · Answer

http://myaspsnippets.blogspot.in/2012/10/bind-dropdownlist-based-on-another.html