[Solved]System.Data.Entity.DynamicProxies.Product Does not contain a property with the name ‘ProductId

 'System.Data.Entity.DynamicProxies.ProductDoes not contain a property
   with the name ‘ProductId’

I got this error “System.Data.Entity.DynamicProxies.Product Does not contain a property with the name ‘ProductId” while binding the object to the dropdownlist using the c# .net. 

Problem:

  public void LoadProductsDropDownList()
        {
               cboProducts.DataTextField = "Name";
               cboProducts.DataValueField = "ProductId ";
               cboProducts.DataSource = db.Products.ToList();
               cboProducts.DataBind();
                ListItem li = new ListItem("Select Product", "-1");
               cboProducts.Items.Insert(0, li);
        }

Solution:

I found the cause of this error due to by mistaken; I left space in DataValueField property field productId . Also, it will happen if you misspelled DataTextField or DataValuefield property values.

  public void LoadProductsDropDownList()
        {
               cboProducts.DataTextField = "Name";
               cboProducts.DataValueField = "ProductId";
               cboProducts.DataSource = db.Products.ToList();
               cboProducts.DataBind();
                ListItem li = new ListItem("Select Product", "-1");
               cboProducts.Items.Insert(0, li);
        }