ASP.NET control in GridView not found to exist in code behind

Question

I have a DropDownList that I would like to populate with column values from a DataBase. However, when I try to bind the DropDownList in code behind, the IDE keeps telling me:

Answer 1

Use this code to bound data to dropdown without using RowDataBound.

Create a function that'll bind the Data to dropdown as follow and call it in Page_Load event

Public void fill_gridView_dropDown()
{
    // your connection and query to retrieve dropdown data will go here 
    // this loop will go through all row in GridView
    foreach(GridViewRow row in your_gridView_Name.Rows) {
        DropDownList  dropDown = (DropDownList)row.FindControl("dropDownList_id");
        dropDown.DataSource = dataSource;
        dropDown.DataValueField = "ValueField";
        dropDown.DataTextField = "TextField";
        dropDown.DataBind();
    }
}

Please note that you have to bind GridView first, and then you have to bind your dropdown

Answer 2

your dropdown is in gridview so you can try with this code

protected void Gridview1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
    var ddl = (DropDownList)e.Row.FindControl("EqpCatDDL'");
    SqlCommand cmd = new SqlCommand("SELECT EqpCateID, EqpCat FROM EqpCategory", connection);

    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    da.Fill(ds);

    EqpCatDDL.DataSource = ds;
    EqpCatDDL.DataValueField = "EqpCateID";
    EqpCatDDL.DataTextField = "EqpCat";
    EqpCatDDL.DataBind();

}
}

Answer 3

You can't directly populate GridView's dropdownlist like this. You need to set datasource of GridView first i.e.

GridView1.DataSource = DataSource

And if you would like to access dropdownlist of this gridview, you can use RowDataBound event handler of GridView i.e.

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    //Checking whether the Row is Data Row
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        //Finding the Dropdown control.
        Control ctrl = e.Row.FindControl("EqpCatDDL");
        if (ctrl != null)
        {
            DropDownList dd = ctrl as DropDownList;
            List lst = new List();
            dd.DataSource = lst;
            dd.DataBind();
        }
    }
}