从代码隐藏绑定下拉列表

Question

I would like to display all my category names in a drop down menu in the latest .net framework. So far, all I have is:

<asp:DropDownList ID="DDCategories" runat="server">
    <asp:ListItem>
    </asp:ListItem>
</asp:DropDownList>

Now I need in Code-Behind to tell the Dropdown that I would like to list all the Name under [Category] in my database. The reason for this is that I am going to create a product in which I would like to choose a category name, but I don't know how to display them in a dropdown.

Answer 1

In case if you are using Linq2Sql or Entity Framework your code will looks like:

DDCategories.DataSource = myDatabaseContext.Category;
DDCategories.DataTextField = "Name";

where Category is generated collection for your table in DB.

Answer 2

While you can certainly do it in code behind, I would suggest to use stored Procedure and pass a parameter to it. Pull the logic in Stored Procedure which data you want to pull. If that is not sufficient to your needs. You may use a code like this

SqlCommand sc = new SqlCommand();
    sc.CommandText = "usp_MyStoredProcedure";
    sc.CommandType = CommandType.StoredProcedure;
    sc.Connection = conn;
    sc.Parameters.Add(AddParam(param1, "@param1"));

DropDwonList DDList = new DropDownList()
DDList = FindControl("DDCategories")

And then execute the stored procedure save the result in DDList data. This is just a start. Hope it helps.

Answer 3

http://www.ezineasp.net/post/Populate-ASP-Net-DropDownList-by-Adding-Items-Dynamically.aspx