The next step is to add the event handlers that hook up all the controls together.
Here is the handler for the SelectedIndexChanged event of the _list control. Add the following code so that when the user selects a new report from the list, the code displays it in design mode:
' a new report was selected: switch to design mode and show it
Private Sub _list_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles _list.SelectedIndexChanged
' switch to design mode
SetDesignMode(True)
' attach selected report to designer and preview controls
_c1rd.Report = Nothing
_c1ppv.Document = Nothing
If _list.SelectedIndex > -1 Then
_c1rd.Report = _list.SelectedItem.Report
End If
End Sub
• C#
// a new report was selected: switch to design mode and show it
private void _list_SelectedIndexChanged(object sender, System.EventArgs e)
{
// switch to design mode
SetDesignMode(true);
// attach selected report to designer and preview controls
_c1rd.Report = null;
_c1ppv.Document = null;
if (_list.SelectedItem != null)
_c1rd.Report = ((ReportHolder)_list.SelectedItem).Report;
}
The designer uses a property grid control (_ppg) to expose the properties of the report elements selected in the designer. This is done by setting the SelectedObject property of the property grid control; in response the control fires a SelectionChanged event.
When the user selects a report section or a field in the designer control, it fires the SelectionChanged event. The event handler inspects the new selection and assigns it to the property grid control. This is a powerful mechanism. The selection can be a single report field, a group of fields, a section, or the whole report.
Add the following code to implement the SelectionChanged event:
' the selection changed, need to update property grid and show the
' properties of the selected object
Private Sub _c1rd_SelectionChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles _c1rd.SelectionChanged
Dim sel As Object() = _c1rd.SelectedFields
If (sel.Length > 0) Then
_lblPropGrid.Text = "Field Properties"
_ppg.SelectedObjects = sel
ElseIf Not IsNothing(_c1rd.SelectedSection) Then
_lblPropGrid.Text = "Section Properties"
_ppg.SelectedObject = _c1rd.SelectedSection
ElseIf Not IsNothing(_c1rd.Report) Then
_lblPropGrid.Text = "Report Properties"
_ppg.SelectedObject = _c1rd.Report
' nothing selected
Else
_lblPropGrid.Text = "Properties"
_ppg.SelectedObject = Nothing
End If
' done
UpdateUI()
End Sub
• C#
// the selection changed, need to update property grid and show the
// properties of the selected object
private void _c1rd_SelectionChanged(object sender, System.EventArgs e)
{
object[] sel = _c1rd.SelectedFields;
if (sel.Length > 0)
{
_lblPropGrid.Text = "Field Properties";
_ppg.SelectedObjects = sel;
}
else if (_c1rd.SelectedSection != null)
{
_lblPropGrid.Text = "Section Properties";
_ppg.SelectedObject = _c1rd.SelectedSection;
}
else if (_c1rd.Report != null)
{
_lblPropGrid.Text = "Report Properties";
_ppg.SelectedObject = _c1rd.Report;
}
else // nothing selected
{
_lblPropGrid.Text = "Properties";
_ppg.SelectedObject = null;
}
// done
UpdateUI();
}
The property grid (_ppg) displays the properties of the object selected in the designer (_c1rd). When the user changes the properties of an object using the grid, the designer needs to be notified so it can update the display. Conversely, when the user edits an object using the designer, the grid needs to be notified and update its display.
Add the following code to implement the handlers for the PropertyValueChanged event of the _ppg control and the ValuesChanged event of the _c1rd control:
' when a value changes in the property window, refresh the designer to show the changes
Private Sub _ppg_PropertyValueChanged(ByVal s As Object, ByVal e As System.Windows.Forms.PropertyValueChangedEventArgs) Handles _ppg.PropertyValueChanged
_c1rd.Refresh()
_dirty = True
UpdateUI()
End Sub
' when properties of the selected objects change in the designer,
' update the property window to show the changes
Private Sub _c1rd_ValuesChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles _c1rd.ValuesChanged
_c1rd.Refresh()
_dirty = True
UpdateUI()
End Sub
• C#
// when a value changes in the property window, refresh the designer
// to show the changes
private void _ppg_PropertyValueChanged(object s,
Systems.Windows.Forms.PropertyValueChangedEventArgs e)
{
_c1rd.Refresh();
_dirty = true;
UpdateUI();
}
// when properties of the selected objects change in the designer,
// update the property window to show the changes
private void _c1rd_ValuesChanged(object sender, System.EventArgs e)
{
_ppg.Refresh();
_dirty = true;
UpdateUI();
}
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