Windows Forms

finalLocation = originalLocation - mouseDownLocation + mouseUpLocation.

private void cb_MouseUp(object sender, MouseEventArgs e)
{
    ComboBox box = sender as ComboBox;
    box.Left += e.X;
    box.Top += e.Y;

    Cursor = Cursors.Default;
}

class CustomButton : System.Windows.Forms.Button
   {
       private bool _DisplayFocusCues = true;
       protected override bool ShowFocusCues
       {
           get
           {
               return _DisplayFocusCues;
           }
       }

       public bool DisplayFocusCues
       {
           get
           {
               return _DisplayFocusCues;
           }
           set
           {
               _DisplayFocusCues = value;
           }
       }
   }

void ToolStripButtonClick(object o, EventArgs e)
{
   ClickFunction();
}

void ClickFunction()
{
   dataGridViewMain.EndEdit();

   //now getting the value of any cell (including  one in selection/edit) returns the actual displayed value
}

Private strSql As String
    Private da As SqlDataAdapter
    Private bs As BindingSource
    Private dtbl As DataTable

    Private Sub PopulateDgv(Optional ByVal strQuery As String = Nothing)
        Dim bs As BindingSource
        Dim cb As SqlCommandBuilder

        Try
            RoomPriceID = New DataGridViewTextBoxColumn
            PeriodDate = New DataGridViewTextBoxColumn
            Day = New DataGridViewTextBoxColumn
            Cost = New DataGridViewTextBoxColumn
            Price = New DataGridViewTextBoxColumn
            Allotment = New DataGridViewTextBoxColumn
            Notes = New DataGridViewTextBoxColumn

            dgvPriceList.Columns.Clear()
            dgvPriceList.DataSource = Nothing
            dgvPriceList.Columns.AddRange(New DataGridViewColumn() {RoomPriceID, PeriodDate, Day, Cost, Price, Allotment, Notes})

            RoomPriceID.Name = "RoomPriceID"
            RoomPriceID.DataPropertyName = "RoomPriceID"
            RoomPriceID.Visible = False
            PeriodDate.Name = "PeriodDate"
            PeriodDate.DataPropertyName = "PeriodDate"
            PeriodDate.ReadOnly = True
            PeriodDate.HeaderText = "Date"
            PeriodDate.Width = 100
            Day.Name = "Day"
            Day.DataPropertyName = "Day"
            Day.ReadOnly = True
            Day.HeaderText = "Day"
            Day.Width = 100
            Cost.Name = "Cost"
            Cost.DataPropertyName = "Cost"
            Cost.HeaderText = "Cost"
            Cost.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight
            Cost.CellTemplate.Style.Alignment = DataGridViewContentAlignment.MiddleRight
            Cost.Width = 100
            Price.Name = "Price"
            Price.DataPropertyName = "Price"
            Price.HeaderText = "Price"
            Price.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight
            Price.CellTemplate.Style.Alignment = DataGridViewContentAlignment.MiddleRight
            Price.Width = 100
            Allotment.Name = "Allotment"
            Allotment.DataPropertyName = "Allotment"
            Allotment.HeaderText = "Allotment"
            Allotment.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight
            Allotment.CellTemplate.Style.Alignment = DataGridViewContentAlignment.MiddleRight
            Allotment.Width = 100
            Notes.Name = "Notes"
            Notes.DataPropertyName = "Notes"
            Notes.HeaderText = "Notes"
            Notes.AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
            Notes.MaxInputLength = 250

            If Not strQuery Is Nothing Then
                bs = New BindingSource
                If dtbl Is Nothing Then dtbl = New DataTable
                da = CreateDataAdapter(strQuery)
                cb = New SqlCommandBuilder(da)
                dtbl.Locale = System.Globalization.CultureInfo.InvariantCulture
                dtbl.Clear()
                da.Fill(dtbl)
                bs.DataSource = dtbl
                dgvPriceList.DataSource = bs
            End If
        Catch ex As Exception
            MsgBox("Error.", MsgBoxStyle.Critical, "Error")
        End Try
    End Sub

    Private Sub frmRoomPriceList_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        strSql = "SELECT [RoomPriceID],Convert(nvarchar(10),[PeriodDate],103) As PeriodDate," & _
        "Convert(nvarchar(15), DATENAME(weekday,[PeriodDate])) As [Day],[Cost],[Price],[Allotment],[Notes] " & _
        "FROM [tblRoomPriceDetails] Where RoomPeriodID = " & Me.cboSrchPeriod.SelectedValue
        PopulateDgv(strSql)
        strSql = Nothing
    End Sub

    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        If dgvPriceList.RowCount > 0 Then
            da.Update(dtbl)
            dtbl.Clear()
            da.Fill(dtbl)
        End If
    End Sub

    Private Sub ToolStripButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton1.Click
        dgvPriceList.EndEdit()
        If dgvPriceList.RowCount > 0 Then
            da.Update(dtbl)
            dtbl.Clear()
            da.Fill(dtbl)
        End If
    End Sub