ASP.Net Datagrid DataFormat String not formatting date as required

Question

I understand this question has been asked before and I have referenced some answers that I have looked at that have not worked for me. However in a .Net 4.0 Web Forms application I have the same DataGrid, and the same code, but using .Net 4.5.1 WebForms application the formatting is different

.Net 4.0

<asp:BoundColumn DataField="Investment Date" DataFormatString="{0:d}" HeaderText="Investment Date" HeaderStyle-CssClass="centre" ItemStyle-CssClass="centre"></asp:BoundColumn>

produces a date format of dd/MM/yyyy - which is the result that I am after

.Net 4.5.1

<asp:BoundColumn DataField="Investment Date" DataFormatString="{0:dd-MM-yyyy}" HeaderText="Investment Date" HeaderStyle-CssClass="centre" ItemStyle-CssClass="centre"></asp:BoundColumn>

and

<asp:BoundColumn DataField="Investment Date" DataFormatString="{0:d}" HeaderText="Investment Date" HeaderStyle-CssClass="centre" ItemStyle-CssClass="centre"></asp:BoundColumn>

produces a result of dd/MM/yyyy hh:mm:ss

I have looked at other stack questions here

• cant format datetime using dataformatstring
• How to fix date format in ASP .NET BoundField (DataFormatString)?
• Date format without time in ASP.NET Gridview

but they have everything that I have tried already.

Just so that I could made sure I wasn't going crazy I have also checked the formatting here too

https://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.boundfield.dataformatstring.aspx and this tells me that I am correct too.

This is how the data is added to the data table

 protected void bttnAddExisting_Click(object sender, EventArgs e)
    {
        var ei = new ExistingInvestments();
        dgExistingInvestments.DataSource = ei.dtExistingInvestments(Session, ddlExistingFundName, ddlExistingFundRiskProfile, ddlExistingFundCustomerName, txtExistingFundInvestmentDate);
        dgExistingInvestments.DataBind();
    }

and this is the class ExistingInvestments

public class ExistingInvestments
{

    public string FundName { get; set; }
    public string FundRiskProfile { get; set; }
    public string CustomerName { get; set; }
    public DateTime InvestmentDate { get; set; }

    public DataTable dtExistingInvestments(HttpSessionState Session, DropDownList ddlExistingFundName, DropDownList ddlExistingFundRiskProfile,
            DropDownList ddlExistingFundCustomerName, TextBox txtExistingFundInvestmentDate)
    {
        if (Session["ExistingInvestmentsTable"] == null)
        {
            var dtExistingFund = new DataTable();

            dtExistingFund.Columns.Add("Fund Name");
            dtExistingFund.Columns.Add("Fund Risk Profile");
            dtExistingFund.Columns.Add("Customer Name");
            dtExistingFund.Columns.Add("Investment Date");
            if (string.IsNullOrEmpty(txtExistingFundInvestmentDate.Text))
            {
                dtExistingFund.Rows.Add(ddlExistingFundName.SelectedValue, ddlExistingFundRiskProfile.SelectedValue,
                    ddlExistingFundCustomerName.SelectedValue, string.Empty);
            }
            else
            {
                dtExistingFund.Rows.Add(ddlExistingFundName.SelectedValue, ddlExistingFundRiskProfile.SelectedValue,
                    ddlExistingFundCustomerName.SelectedValue, Convert.ToDateTime(txtExistingFundInvestmentDate.Text));
            }

            Session["ExistingInvestmentsTable"] = dtExistingFund;
            return dtExistingFund;
        }
        else
        {
            var dt = (DataTable)Session["ExistingInvestmentsTable"];

            if (string.IsNullOrEmpty(txtExistingFundInvestmentDate.Text))
            {
                dt.Rows.Add(ddlExistingFundName.SelectedValue, ddlExistingFundRiskProfile.SelectedValue,
                    ddlExistingFundCustomerName.SelectedValue, string.Empty);
            }
            else
            {
                dt.Rows.Add(ddlExistingFundName.SelectedValue, ddlExistingFundRiskProfile.SelectedValue,
                    ddlExistingFundCustomerName.SelectedValue, Convert.ToDateTime(txtExistingFundInvestmentDate.Text.Trim()));
            }

            Session["ExistingInvestmentsTable"] = dt;
            return dt;
        }          
    }
}

Any and all help greatly appreciated If anyone could help that would be great.

Answer 1

You did not specify the data type of the columns in the DataTable. Therefore formatting will be difficult. Make the column a DateTime column.

dtExistingFund.Columns.Add("Investment Date", typeof(DateTime));