Datepicker Databinding Dilemma

[Guy]

Morning,

I think this question is not directly Telerik related but hopefully someone can help.

I have a datepicker and gridview databound. When I select a row on the gridview, the datepicker updates as I would expect but if I select a row with a blank date (DBNull I believe?) then it still retains the avlue from the previously picked date but still treats it as a null value.

I have looked through all the options I can think of in Formatting and Advanced Binding but nothing seems to work. I have also looked at ways of refreshing the databinding on row change but got no where (plus I don't think that's really the correct way of doing things).

If anyone could help or point me in the right direction i'd really appreciate it!

Kind regards,


Guy

[Richard Slade]

Hello Guy, 

You have a gridview, and a separate datetime picker. Is that correct? And as you select different rows, you grab the date from one of the cells in the selected row and make that the date in the datetimepicker. Is that correct? 

If this is the case, you can check to see if the current cell is null, and if so, also set the datetimepicker value to null. You can set a null default date in the date time picker also. 

Let me know if that helps, or indeed doesn't. 
Best regards, 
Richard

[Guy]

Hi Richard,

Both the gridview and datepicker are bound to the same bindingsource. The datepicker exists with a few other bound controls which the user can then save.

If the user selects a row with a blank date in it, the displayed value of the datepicker is the same as the last row selection which is confusing the users as they think thhe date will save but the value is still being stored as null.

I obviously need a value to blank out that value if it's null. I have tried Databinding both the Value and Text of the datepicker and have set a blank space as the Null value for both. I have also set the Nulldate property of the control to a blank space too but no luck.

Would the best course of action be to check on the rowchange to see if the currentrow has a nulldate and then set the text to "";?

Thanks,

Guy

[Richard Slade]

Hi Guy,

Apologies if I'm not getting this straight away, but the RadDateTimePicker does not have a datasource property. How are you setting the the value of the radDateTimePicker?
thanks
Richard

[Guy]

Hi Richard,

I'm setting it from within the (DataBindings) property at the top of the Properties window. Then within Formatting and Advanced Binding I am setting the value to the bindingsource.

I hope this helps.

Guy

[Richard Slade]

Hi Guy,

Ah, ok, I see what you mean, though personally, i think this exampel would be easier. With this it shows the dates in the grid, and then has a null date and null text in the RadDateTimePicker.

Let me know if that helps
Richard

Imports System
Imports System.ComponentModel

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            Dim somethings As New Somethings()
            Me.RadGridView1.BeginUpdate()
            Me.RadGridView1.DataSource = New BindingList(Of Something)(somethings.GetSomethings())
            Me.RadGridView1.MasterTemplate.BestFitColumns()
            Me.RadGridView1.EndUpdate()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub


    Private Sub RadGridView1_SelectionChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RadGridView1.SelectionChanged
        If Me.RadGridView1.CurrentRow.Cells("TheDate") IsNot Nothing Then
            Me.RadDateTimePicker1.Value = Convert.ToDateTime(Me.RadGridView1.CurrentRow.Cells("TheDate").Value)
        End If
    End Sub
End Class

Public Class Somethings
    Public Function GetSomethings() As System.Collections.Generic.List(Of Something)
        Dim somethingList As New System.Collections.Generic.List(Of Something)
        somethingList.Add(New Something("", "Blank Name Description", New DateTime(1999, 1, 3)))
        somethingList.Add(New Something("Name", "none", New DateTime(1999, 1, 2)))
        somethingList.Add(New Something("Name1", "Description1", New DateTime(1999, 1, 1)))
        somethingList.Add(New Something("Name2", "Description2", New DateTime(1999, 1, 4)))
        somethingList.Add(New Something("Name3", "Description3", New DateTime(1999, 1, 5)))
        somethingList.Add(New Something("Name4", "Description4", Nothing))
        Return somethingList
    End Function
End Class

Public Class Something

    Private m_Name As String
    Private m_Description As String
    Private m_Date As DateTime

    Public Sub New()
    End Sub

    Public Sub New(ByVal name As String, ByVal description As String, ByVal theDate As DateTime)
        m_Name = name
        m_Description = description
        m_Date = theDate
    End Sub

    Public Property Name() As String
        Get
            Return m_Name
        End Get
        Set(ByVal value As String)
            m_Name = value
        End Set
    End Property

    Public Property Description() As String
        Get
            Return m_Description
        End Get
        Set(ByVal value As String)
            m_Description = value
        End Set
    End Property

    Public Property TheDate() As DateTime
        Get
            Return m_Date
        End Get
        Set(ByVal value As DateTime)
            m_Date = value
        End Set
    End Property

End Class

[Guy]

Hi Richard,

Taking some ideas from your post I have come up with the following solution

private void radGridView1_SelectionChanged(object sender, EventArgs e)
{
    if (this.radGridView1.CurrentRow is GridViewGroupRowInfo || this.radGridView1.CurrentRow is GridViewNewRowInfo)
    {
        return;
    }
    if (this.radGridView1.CurrentRow is GridViewFilteringRowInfo || this.radGridView1.CurrentRow is GridViewFilteringRowInfo)
    {
        return;
    }

    if (this.radGridView1.CurrentRow.Cells["DateCalled"].Value.ToString() != "")
    {
        this.LastDateCalledPicker.Value = Convert.ToDateTime(this.radGridView1.CurrentRow.Cells["DateCalled"].Value);
        return;
    }

    this.LastDateCalledPicker.DateTimePickerElement.SetToNullValue();
}

Thanks once again for all your help!

Best regards,

Guy

[Richard Slade]

Great. Glad you have it working now, Guy. 

All the best
Richard