[Solved] Selected Value of DropDownList inside GridView getting lost on PostBack in ASP.Net

I can not get the Selected Item value in in GridView Dropdowntemplate Feild

I Get Only First index item text value

string ItemSkuCode = ddlIMEntity.SelectedItem.Text + "-" + txtIMItem.Text + " -";
        foreach (GridViewRow tempr in gvParameter.Rows)
        {
            DropDownList ddl = (DropDownList)tempr.FindControl("ddlParameterValue");
//            string str1 = Request.Form[ddl.UniqueID.];
            if (ddl.Items.Count > 0)
            {
                string str = ddl.SelectedItem.Text;
                if (str.Length > 2)
                {
                    ItemSkuCode += " " + str.Substring(0, 3);
                }
                else
                {
                    ItemSkuCode += " " + str;
                }
            }
        }