ASP.NET C# - A function with arguments to write dropdownlist

Question

I am new to ASP.NET and C#.

What I am trying to do is some type of function where I can feed some argumennts, which will generate a dropdown list box for me. I know ASP.NET is much better, but I couldn't figure out how to accomplish similar or even better.

When I've done before with classic ASP/VBScript was I have a Sub routine to generate a dropdown list. Example:

Sub CreateSelectBox(selectboxID, onChangeTrigger, selectedValue, SQLTable, and SQLCondition)
     ' ... Query the databse from SQLTable, write a SelectBox with option values, and selected the selectedValue for arguments....
End Sub

So, all I have to do in the any submit form is just one line of code. like this:

<tr><td><%CreateSelectBox "DropDownList1", "onChangeRunJavascript123();", "Selected123", "SQL_CustomerTable", "where CustomerType = 'Consumer' order by SortOrder ASC" %></td></tr>

Please advise a better way to do this in ASP.Net C#, please provide a code sample if possible since I am new.

Thanks in advance,

Are you using ASP.NET Web Forms (asp.net/web-forms), ASP.NET MVC (asp.net/mvc) or ASP.NET Web Pages (asp.net/web-pages)? — MichaC
– MichaC, Commented Oct 5, 2012 at 22:44

codingbiz · Accepted Answer · 2012-10-05 23:03:46Z

2

Asp.net has a DropdownList control that helps to do that, this is very old tutorial and Databound Controls

Markup: .aspx file

<asp:DropdownList runat="server" ID="MyList" DataTextField="PersonName" DataValueField="PersonID">

</asp:DropdownList>

CodeBehind: .aspx.cs file

protected void Page_Load(object sender, EventArgs e)
{
   if(!Page.IsPostBack)
   {
       MyList.DataSource = getDataFromDB();
       MyList.DataBind();
   }
}


//this function can return IEnumerable e.g. DataTable of Person, List<Person>, SqlDataReader etc
private DataTable getDataFromDB()
{
   //select data from database
   //return data;
}

edited Oct 5, 2012 at 23:03

answered Oct 5, 2012 at 22:41

codingbiz

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3 Comments

immutabl Over a year ago

+1. I'd also suggest that Milacay reads up on data bound controls in general - that syntax suggests a background in ASP or Php :)

codingbiz Over a year ago

Yes I agree. I couldn't find a tutorial that's simple

immutabl Over a year ago

Sam's Teach Yourself ASP.Net in ...?

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