ASP.NET GridView: How to Control the Format of a Column in Edit Mode?

Question

Given the following GridView:

<asp:GridView runat="server" ID="GridMenuItemAttributes" DataKeyNames="MenuItemAttributeID" AutoGenerateColumns="false" 
        OnRowCommand="GridMenuItemAttributes_RowCommand" DataSourceID="DSMenuItemAttributes" OnRowEditing="GridMenuItemAttributes_RowEditing" >
<Columns>
    <asp:BoundField HeaderText="Description" DataField="DisplayName" />
    <asp:BoundField HeaderText="Price" DataField="Price" DataFormatString="{0:F2}" />
    <asp:CommandField ShowEditButton="true" ShowDeleteButton="true"
            EditText="Edit" DeleteText="Delete" />
</Columns>
</asp:GridView>

The Price field correctly formats with two decimal places when viewing a row, but changes to four decimal places when I'm editing a row. I've tried different formats (e.g., "C", "0.00") and attached the following OnRowEditing handler:

protected void GridMenuItemAttributes_RowEditing( object sender, GridViewEditEventArgs e )
{
    int menuItemAttributeID = Convert.ToInt32( GridMenuItemAttributes.DataKeys[ e.NewEditIndex ].Value );

    if ( ! String.IsNullOrEmpty( GridMenuItemAttributes.Rows[ e.NewEditIndex ].Cells[ 1 ].Text ) )
    {
        String theValue = GridMenuItemAttributes.Rows[ e.NewEditIndex ].Cells[ 1 ].Text;
        GridMenuItemAttributes.Rows[ e.NewEditIndex ].Cells[ 1 ].Text = String.Format( "{0:0.00}", Convert.ToDouble( theValue ) );
    }
}

all to no avail. The client insists, and reasonably so, that when editing the cell, the value should be displayed with two decimal places.

Answer 1

By default, the formatting string is applied to the field value only when the data-bound control that contains the BoundField object is in read-only mode. To apply the formatting string to field values while in edit mode, set the ApplyFormatInEditMode property to true.

From: MSDN DataFormatString

Hope that helps