In the demo of the ObjectListView control there is this code (in the "Complex Example" tab page)
to allow for a custom editor (a ComboBox) (Adapted
to my case and edited for clarity):
EventHandler CurrentEH;
private void ObjectListView_CellEditStarting(object sender,
CellEditEventArgs e)
{
if (e.Column == SomeCol)
{
ISomeInterface M = (e.RowObject as ObjectListView1Row).SomeObject; //(1)
ComboBox cb = new ComboBox();
cb.Bounds = e.CellBounds;
cb.DropDownStyle = ComboBoxStyle.DropDownList;
cb.DataSource = ISomeOtherObjectCollection;
cb.DisplayMember = "propertyName";
cb.DataBindings.Add("SelectedItem",
M, "ISomeOtherObject", false,
DataSourceUpdateMode.Never);
e.Control = cb;
cb.SelectedIndexChanged +=
CurrentEH = (object sender2, EventArgs e2) =>
M.ISomeOtherObject =
(ISomeOtherObject)((ComboBox)sender2).SelectedValue; //(2)
}
}
private void ObjectListView_CellEditFinishing(object sender,
CellEditEventArgs e)
{
if (e.Column == SomeCol)
{
// Stop listening for change events
((ComboBox)e.Control).SelectedIndexChanged -= CurrentEH;
// Any updating will have been down in the SelectedIndexChanged
// event handler.
// Here we simply make the list redraw the involved ListViewItem
((ObjectListView)sender).RefreshItem(e.ListViewItem);
// We have updated the model object, so we cancel the auto update
e.Cancel = true;
}
}
I have too many other columns with combo editors inside objectlistviews
to use a copy& paste strategy (besides, copy&paste is a serious source of bugs), so I tried
to parameterize the code
to keep the code duplication
to a minimum. ObjectListView_CellEditFinishing is a piece of cake:
HashSet<OLVColumn> cbColumns = new HashSet<OLVColumn> (new OLVColumn[] { SomeCol, SomeCol2, ...};
private void ObjectListView_CellEditFinishing(object sender,
CellEditEventArgs e)
{
if (cbColumns.Contains(e.Column)) ...
but ObjectListView_CellEditStarting is the problematic.
I guess in CellEditStarting I will have
to discriminate each case separately:
private void ObjectListView_CellEditStarting(object sender,
CellEditEventArgs e)
{
if (e.Column == SomeCol)
// code
to create the combo, put the correct list as the datasource, etc.
else if (e.Column == SomeOtherCol)
// code
to create the combo, put the correct list as the datasource, etc.
And so on.
But how can I parameterize the "code
to create the combo, put the correct list as the datasource, etc."? Problem lines are
(1) Get SomeObject. the property NAME varies.
(2) Set ISomeOtherObject, the property name varies too.
The types vary too, but I can cover those cases with a generic method combined with a not so "typesafe" API (for instance, the cb.DataBindings.Add and cb.DataSource both use an object)
Reflection? more lambdas? Any ideas? Any other way
to do the same?
PS: I want
to be able
to do something like this:
private void ObjectListView_CellEditStarting(object sender,
CellEditEventArgs e)
{
if (e.Column == SomeCol)
SetUpCombo<ISomeInterface>(ISomeOtherObjectCollection,
"propertyName",
SomeObject,
ISomeOtherObject);
else if (e.Column == SomeOtherCol)
SetUpCombo<ISomeInterface2>(ISomeOtherObject2Collection,
"propertyName2",
SomeObject2
ISomeOtherObject2);
and so on. Or something like that.
I know, parameters SomeObject and ISomeOtherObject are not real parameters per see, but you get the idea of what I want. I want not
to repeat the same code skeleton again and again and again.
One solution would be "preprocessor generics" like C's DEFINE, but I don't thing c# has something like that.
So, does anyone have some alternate ideas
to solve this?
