DataGrid ships with WPF; MahApps restyles it and everything inside it. There is one alternative look, a Windows 10 and a WinUI look on develop, one variant for long grids, and a set of properties for the parts of a grid that WPF gives you no other way to reach.

The implicit style

Styles/Controls.xaml applies MahApps.Styles.DataGrid to every DataGrid. Merging that dictionary — which the quick start does — is all it takes:

<ResourceDictionary Source="pack://application:,,,/MahApps.Metro;component/Styles/Controls.xaml" />

<DataGrid ItemsSource="{Binding Albums}" />

Only the DataGrid itself has an implicit style. Everything inside it — rows, cells, headers — is styled because the grid's style hands those styles down:

So restyling one part means replacing that one property, not the grid:

<DataGrid CellStyle="{StaticResource MyCell}" />

Along with the look the style also sets some behaviour: GridLinesVisibility to None, HeadersVisibility to Column — so no row headers unless you ask — and MinRowHeight to 25.

The Azure style

MahApps.Styles.DataGrid.Azure is a variant modelled on the grids in the Azure portal. It swaps in Azure versions of the same four styles:

<DataGrid ItemsSource="{Binding Albums}"
          Style="{StaticResource MahApps.Styles.DataGrid.Azure}" />

There is also MahApps.Styles.DataGridRow.AzureWithMargin, the Azure row with a one-pixel bottom margin, which separates the rows into cards rather than a continuous table:

<DataGrid Style="{StaticResource MahApps.Styles.DataGrid.Azure}"
          RowStyle="{StaticResource MahApps.Styles.DataGridRow.AzureWithMargin}" />

The Windows 10 and the WinUI look

MahApps.Styles.DataGrid.Win10 follows the DataGrid of the Windows Community Toolkit, the one UWP had, and MahApps.Styles.DataGrid.WinUI the TableView of WinUI 3. The Win10 and the WinUI set apply them by type. Each grid hands its headers, rows and cells their look itself, and its columns the boxes of its set to show and edit values in, so a grid with the key looks the same in a window of the default set, and a grid whose style stands on the Metro one keeps the Metro rows inside a set.

<DataGrid ItemsSource="{Binding Albums}"
          Style="{StaticResource MahApps.Styles.DataGrid.WinUI}" />

The template is the Metro one, so sorting, resizing, frozen columns and the row details work as in the Metro grid; only the parts look different. Both styles set DataGridHelper.CellPadding and ColumnHeaderPadding to the spacing of their originals, so set those on the grid to change it.

The colours are in the theme as MahApps.Brushes.DataGrid.Win10.* and MahApps.Brushes.DataGrid.WinUI.*, the row heights as MahApps.Sizes.DataGrid.RowHeight.Win10 and .WinUI, and the cell padding as MahApps.Thickness.DataGrid.CellPadding.Win10 and .WinUI.

Padding and selection

DataGridHelper carries what WPF leaves out. The full table is on the DataGridHelper page; the four that matter most here:

<DataGrid mah:DataGridHelper.CellPadding="10 6"
          mah:DataGridHelper.ColumnHeaderPadding="10 8" />

EnableCellEditAssist is the one that changes how the grid feels: without it, a check box column needs one click to select the cell and another to hit the box.

Virtualisation

A DataGrid virtualises its rows by itself — EnableRowVirtualization is True out of the box — and the MahApps style sets ScrollViewer.CanContentScroll to True, so it scrolls by item rather than by pixel. Two things are off until you ask for them: EnableColumnVirtualization, and VirtualizingPanel.IsVirtualizingWhenGrouping, which is the one that hurts. A grouped grid realises a row for every item it has, and the style's own trigger then switches CanContentScroll back off, because item scrolling and non-virtualised groups do not mix. A few hundred grouped rows take seconds to appear that way, and scroll no better afterwards.

MahApps.Styles.DataGrid.Virtualized is the base style with all of it turned on: rows, columns, item scrolling, recycled containers and virtualisation while grouping.

<DataGrid ItemsSource="{Binding GroupedAlbums}"
          Style="{StaticResource MahApps.Styles.DataGrid.Virtualized}" />

<DataGrid VirtualizingPanel.IsVirtualizingWhenGrouping="True"
          VirtualizingPanel.VirtualizationMode="Recycling" />

Column virtualisation is the part of that style worth a thought before you use it, which is also why it is a style of its own rather than a change to the implicit one. An Auto column width needs every cell of that column measured, and not measuring the cells that are off screen is precisely what column virtualisation does, so the two work against each other. Explicit or star widths keep the layout still while the grid scrolls sideways; otherwise set EnableColumnVirtualization back to False on the grid and keep the rest.

Grouping

Grouping is WPF's own, and MahApps styles the group headers through MahApps.Styles.GroupItem.DataGrid, whose expander uses MahApps.Styles.ToggleButton.ExpanderHeader.Down.DataGrid.GroupItem. Point the grid's GroupStyle at it:

<DataGrid ItemsSource="{Binding GroupedAlbums}">
    <DataGrid.GroupStyle>
        <GroupStyle ContainerStyle="{StaticResource MahApps.Styles.GroupItem.DataGrid}" />
    </DataGrid.GroupStyle>
</DataGrid>

As with a ComboBox, the grouping itself comes from the bound collection being a grouped view, not from the grid. The container style only dresses the headers; what grouping costs is the virtualisation above.

Related

The columns and the controls inside them have a page of their own: DataGrid Columns.