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gridview bind dropdownlist to List<keyvaluePair<int, string>>

I have a number of tables in my DB that hold references to an key value pair:

types of phone numbers:

  • 1 - Home
  • 2 - Work
  • 3 - Mobile
  • 4 - Fax

etc

So I have a table for the types and when they are used in other tables they reference the int value as a foreign key. When I have been pulling them out I have been storing them as keyvaluepair<int, string> items in the class that is using them.

When I needed to get a list of them I thought I would just create a List<> of them rather than use two different types of data types to get the same data.

My problem has arrived when I need to populate a dropdownlist within a gridview when I am using the edittemplate bit. If I use a datasource to pull this out it will write [1 Home] in the text rather than put the int as the value and Home as the text to display.

I guess I have a multiple part question really.

One:

Am I being stupid? Is this a really bad way to get the data out and store it (the keyvaluepair part)? Should I just be storing it all in a datatable? I didn't like to put it all in datatable. I have my DAL taking to my BLL and have tried to encapsulate everything as objects or List<>'s of objects rather than tables of everything. Most the time this has worked well.

Two:

If I was using some object rather than a datatable to bind into my objectdatasource for the dropdownlist, how can I set the currently selected value, rather than have it just have the first item in the list selected?

EDIT

As was pointed out below I was being an idiot and just needed to set the DataValueField and DataKeyField.

To get the dropdownlist to bind I just had to do:

SelectedValue='<%# DataBinder.Eval(Container, "DataItem.PhoneType.Key") %>'

The reason I didn't see that one straight away was because it was not showing up in my intellisense but when I manually typed it in, it worked.

like image 592
Jon Avatar asked Jan 31 '09 20:01

Jon


1 Answers

Use a Dictionary<int, string> and set your DropDown DataValueField to Key and DataTextField to Value.

    // A sample dictionary:
    var dictionary = new Dictionary<int, string>();
    dictionary.Add(1, "Home");
    dictionary.Add(2, "Work");
    dictionary.Add(3, "Mobile");
    dictionary.Add(4, "Fax");

    // Binding the dictionary to the DropDownList:
    dropDown.DataTextField = "Value";
    dropDown.DataValueField = "Key";
    dropDown.DataSource = dictionary;  //Dictionary<int, string>
    dropDown.DataBind();
like image 148
Christian C. Salvadó Avatar answered Nov 01 '22 22:11

Christian C. Salvadó