Enhance aggregate functions (like Sum) in footers so they support expression columns in RadGridView. 

See the attached project. It works for DataColumn, but raises an exception that no suitable generic Sum method could be found when I set the Sum footer for an expression column.

Columns data gets overlapped when columns are hidden and shown again

Add a property to control GridView ControlPanelItem visibility.

When Unicode characters are copy pasted from grids via CTRL + C and then pasted into Excel or Word (for example) as a HTML table, it seems like for every Unicode character a certain amount of bytes / characters are cut off from the end result.

The built-in export capabilities for the RadGridView are clunky and not well though out. Additionally, it doesn't fully support exporting hierarchical child data. (You can do it, but you have to go through a good bit of song and dance for something that I've seen other tool sets do automatically.)

I'd like to see the option fully baked that doesn't require code-behind (allowing an MVVM approach). And asynchronous methods that uses standard async-await conventions.

The default merging algorith merges adjacent cells with the same value. An option for preventing cells merging despite their value, should be provided.

If in the content of RadGridView.ControlPanelItem has a binding with a RelativeSource or ElementName and the grid is placed in the collapsed UserControl, a binding error is thrown in the output window.

By default, the RadGridView will expand its rows to fit whatever the size of the text content. If you have a large amount of text with newlines, it essentially renders the grid unusable in this state.

The thread http://www.telerik.com/forums/limit-row-height suggests two workaround: 1) using a converter to remove newlines- this is a bad solution because it means the binding on the column must be one-way. 2) Applying styling to the grid's textblock- also not great because its non-obvious and requires a lot of boilerplate.

My suggestion is two properties on the RadGridView: MaxRowHeight and MultilineRowContentBehavior. This second property would determine what happens when a row has multiline content and would take an enumeration: SizeHeightToContent- the current behavior. SingleLineExpandOnEdit- when displaying, shows only a single line of the multiline content. When editing, expands the TextBox to fit the content. SingleLine- displays and edits the content in a single line.

This issue manifests when RadGridView loaded some columns first (which are working) and then add more columns. The additional columns cannot paste values in their cells.

To work this around, mark the new columns as auto generated and call one of the internal methods.

newColumn.IsAutoGenerated = true;
this.gridView.Columns.Add(newColumn);

var collectionViewPropInfo = this.gridView.Items.GetType().GetProperty("CollectionView", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
var qcv = (QueryableCollectionView)collectionViewPropInfo.GetValue(this.gridView.Items);
var methodInfo = qcv.GetType().GetMethod("OnElementTypeChanged", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
methodInfo.Invoke(qcv, new object[0]);

When the ScrollMode is set to Deferred, then only the vertical ScrollBar shows a position indicator. The same is requested on horizontal scrolling.