Populating an ASP.Net Drop Down List with DataSet data from DataSet created with DataSet designer

问题

We have an ASP.Net / VB.Net web form containing a drop down list in the markup of the aspx file. There is also a DataSet created with the DataSet designer.

We would like to populate the drop down with data from the DataSet.

Can you show me some sample markup and / or VB.Net coding that is required to populate the drop down list with the DataSet data?

回答1:

<asp:DropDownList ID="MyDropDownList" runat="server" DataTextField="SomeString" DataValueField="SomeUniqueId" />

Code-behind:

protected void Page_Load(object sender, EventArgs e)
{
    var myDataSet = new DataSet(); // replace with your dataset
    MyDropDownList.DataSource = myDataSet;
    MyDropDownList.DataBind();
}

VB.Net:

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
    Dim aDataSet As DataSet
    MyDropDownList.DataSource = aDataSet
    MyDropDownList.DataBind()
End Sub

And you see the "DataTextField" and "DataValueField" in the markup? There's where you put the name of fields you want to use as id (data value) and to display (data text) in the drop-down list.

Here's an example:

Markup

<body>
    <form id="form1" runat="server">
        <div>
            Fruits
            <asp:DropDownList ID="DropDownListWithFruits" runat="server" DataTextField="FruitName" DataValueField="FruitId" />
        </div>
    </form>
</body>

Code behind

protected void Page_Load(object sender, EventArgs e)
{
    var myDataSet = new DataSet();
    var table1 = new DataTable();
    table1.Columns.Add("FruitName");
    table1.Columns.Add("FruitId");
    table1.Rows.Add("Apple", 1);
    table1.Rows.Add("Banana", 2);
    table1.Rows.Add("Grapefruit", 3);

    myDataSet.Tables.Add(table1);

    DropDownListWithFruits.DataSource = myDataSet;
    DropDownListWithFruits.DataBind();
}