ObjectListView - Rows are formatted only after MouseOver on Items

Question

I am in need of some assistance or advice/experience of someone else. Here is what I'm struggling with:

In my project an objectlistview olvDifference is used to visualize items (Type Conflict) of a list. So far I was able to add the Columns needed and format them properly. But the format provided with

private void ConflictFormatRow(object sender, 
BrightIdeasSoftware.FormatRowEventArgs e)
{
  Conflict conflict = (Conflict)e.Model;
  if (conflict == null) return;
  if (conflict.resolution == ConflictResolution.None) e.Item.BackColor = conflictColor;
  else if (conflict.resolution == ConflictResolution.UseMine) e.Item.BackColor = mineColor;
  else if (conflict.resolution == ConflictResolution.UseTheirs) e.Item.BackColor = theirsColor;
  else e.Item.BackColor = System.Drawing.Color.White;
  if(e.Model == olvConflictList.SelectedObject)
  {
    BrightIdeasSoftware.RowBorderDecoration a = new BrightIdeasSoftware.RowBorderDecoration();
    a.BorderPen.Color = Color.Black;
    a.BorderPen.Width = 3;
    a.CornerRounding = 0;
    a.FillBrush = Brushes.Transparent;
    e.Item.Decoration = a;
  }
  else
  {
    BrightIdeasSoftware.RowBorderDecoration b = new BrightIdeasSoftware.RowBorderDecoration();
    b.BorderPen.Color = Color.Transparent;
    b.BorderPen.Width = 0;
    b.CornerRounding = 0;
    b.FillBrush = Brushes.Transparent;
    e.Item.Decoration = b;
  }
}

In the constructor of the form (WFA), the AspectGetter is assigned and the objects to display are set.

Designer-Generated code equals the block below:

  // 
  // olvConflictList
  // 
  this.olvConflictList.AllColumns.Add(this.olvcConflictList);
  this.olvConflictList.Anchor = System.Windows.Forms.AnchorStyles.Bottom;
  this.olvConflictList.CellEditUseWholeCell = false;
  this.olvConflictList.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
        this.olvcConflictList});
  this.olvConflictList.Cursor = System.Windows.Forms.Cursors.Default;
  this.olvConflictList.FullRowSelect = true;
  this.olvConflictList.Location = new System.Drawing.Point(780, 90);
  this.olvConflictList.Name = "olvConflictList";
  this.olvConflictList.Size = new System.Drawing.Size(286, 489);
  this.olvConflictList.TabIndex = 18;
  this.olvConflictList.UseCellFormatEvents = true;
  this.olvConflictList.UseCompatibleStateImageBehavior = false;
  this.olvConflictList.View = System.Windows.Forms.View.Details;
  this.olvConflictList.FormatRow += new System.EventHandler<BrightIdeasSoftware.FormatRowEventArgs>(this.ConflictFormatRow);
  this.olvConflictList.SelectedIndexChanged += new System.EventHandler(this.olvDifferenceGroups_SelectedIndexChanged);
  // 
  // olvcConflictList
  // 
  this.olvcConflictList.AspectName = "";
  this.olvcConflictList.AutoCompleteEditor = false;
  this.olvcConflictList.AutoCompleteEditorMode = System.Windows.Forms.AutoCompleteMode.None;
  this.olvcConflictList.FillsFreeSpace = true;
  this.olvcConflictList.Groupable = false;
  this.olvcConflictList.HeaderCheckBoxUpdatesRowCheckBoxes = false;
  this.olvcConflictList.Hideable = false;
  this.olvcConflictList.IsEditable = false;
  this.olvcConflictList.MinimumWidth = 50;
  this.olvcConflictList.Searchable = false;
  this.olvcConflictList.Sortable = false;
  this.olvcConflictList.Text = "Conflicts";
  this.olvcConflictList.UseFiltering = false;
  this.olvcConflictList.Width = 283;

The only item in the olv has no BackGroundColor (White, default):

After starting the process, it is shown as one can see in the pic above, but I'd expect it to be initialized as in the pic below (after I hovered over it with my mouse the first time).

The only item in the olv has BackGroundColor conflictColor as assigned in the ConflictFormatRow:

Where do I need to improve my code? Any advices?

Answer 1

Well, I could figure it out myself. I took a look at the source of OLV and what i found out so far:

In my case, the first row, here "Conflicts", was set to "Groupable=False", but the OLV itself was set to "ShowGroups=True". FormatRow is fired in PostProcessOneRow, which is called according to source (Version: 2.9.1.0) in following logic:

protected virtual void PostProcessRows() {
        // If this method is called during a BeginUpdate/EndUpdate pair, changes to the
        // Items collection are cached. Getting the Count flushes that cache.
#pragma warning disable 168
// ReSharper disable once UnusedVariable
        int count = this.Items.Count;
#pragma warning restore 168

        int i = 0;
        if (this.ShowGroups) {
            foreach (ListViewGroup group in this.Groups) {
                foreach (OLVListItem olvi in group.Items) {
                    this.PostProcessOneRow(olvi.Index, i, olvi);
                    i++;
                }
            }
        } else {
            foreach (OLVListItem olvi in this.Items) {
                this.PostProcessOneRow(olvi.Index, i, olvi);
                i++;
            }
        }
    }

Since grouping failed, due to no groupable rows being present in OLV, the PostProcessOneRow in the if-body was not hit even once (foreach operated in "this.Groups" whichs count was 0).

Set "ShowGroups=False", works like a charm now.