TableDesigner::GetDesignTimeHtml Method ()
Gets the HTML that is used to represent the control at design time.
Assembly: System.Design (in System.Design.dll)
The GetDesignTimeHtml method ensures that the table has at least one row and cell and that the cells contain some text for display at design time.
The following code example demonstrates how to override the GetDesignTimeHtml method to display rows and cells for the StyledTable class on the design surface. In the Try block, the code checks whether the table contains any rows or cells, and if it does not, creates a row and performs a loop to create two cells for the row, along with placeholder text to display in each cell at design time. If the table is not empty, but a row is, the code performs the same loop to create and populate the cells. In the Finally block, the code returns the values to their original state.
' Override the GetDesignTimeHtml method to display ' placeholder text at design time for the ' rows and cells of the StyledTable class. Public Overrides Function GetDesignTimeHtml() As String Dim sTable As StyledTable = CType(Component, StyledTable) Dim designTimeHTML As String Dim rows As TableRowCollection = sTable.Rows Dim cellsWithDummyContents As ArrayList = Nothing Dim emptyTable As Boolean = rows.Count = 0 Dim emptyRows As Boolean = False Dim counter As Integer = 1 Dim numcells As Integer = 2 Try ' Create two cells to display ' in a row at design time. If emptyTable Then Dim row As TableRow = New TableRow() rows.Add(row) Dim i As Integer For i = 0 To numcells - 1 Dim c As TableCell = New TableCell() c.Text = "Cell #" & counter.ToString() counter += 1 rows(0).Cells.Add(c) Next i Else emptyRows = True Dim j As Integer For j = 0 To rows.Count - 1 If rows(j).Cells.Count <> 0 Then emptyRows = False Exit For End If Next j If emptyRows = True Then Dim k As Integer For k = 0 To numcells - 1 Dim c As TableCell = New TableCell() c.Text = "Cell #" & counter.ToString() counter += 1 rows(0).Cells.Add(c) Next k End If End If If emptyTable = False Then ' If the rows and cells were defined by the user, but the ' cells remain empty this code defines a string to display ' in them at design time. Dim row As TableRow For Each row In rows Dim c As TableCell For Each c In row.Cells If ((c.Text.Length = 0) AndAlso (c.HasControls() = False)) Then If cellsWithDummyContents Is Nothing Then cellsWithDummyContents = New ArrayList() End If cellsWithDummyContents.Add(c) c.Text = "Cell #" & counter.ToString() counter += 1 End If Next c Next row End If ' Retrieve the design-time HTML for the StyledTable class. designTimeHTML = MyBase.GetDesignTimeHtml() Finally ' If the StyledTable was empty before the dummy text was added, ' restore it to that state. If emptyTable Then rows.Clear() Else ' Clear the cells that were empty before the dummy text ' was added. If Not (cellsWithDummyContents Is Nothing) Then Dim c As TableCell For Each c In cellsWithDummyContents c.Text = [String].Empty Next c End If If emptyRows Then rows(0).Cells.Clear() End If End If End Try Return designTimeHTML End Function
Available since 1.1