You should be doing this through Style
/Trigger
or Binding
with a converter like
<DataGrid Name="dataGrid"
...>
<DataGrid.Columns>
<DataGridTextColumn Header="column4" Binding="{Binding column4}">
<DataGridTextColumn.CellStyle>
<Style TargetType="DataGridCell">
<Style.Triggers>
<DataTrigger Binding="{Binding column4}" Value="232">
<Setter Property="Background" Value="Red"/>
</DataTrigger>
</Style.Triggers>
</Style>
</DataGridTextColumn.CellStyle>
</DataGridTextColumn>
<!--...-->
</DataGrid.Columns>
<!--...-->
</DataGrid>
By default, the DataGrid
is using virtualization so only the DataGridRows
that are visible to the user at the moment will be loaded. The other rows will be created once they become visible so if you're trying to style some cells in code behind in can become pretty messy (the cell you are trying to access might not even exist yet.)
To get a DataGridCell
at index row/column you can define a helper class (DataGridHelper
) and use it like this
DataGridCell cell = DataGridHelper.GetCell(dataGrid, 0, 2);
if (cell != null)
{
cell.Background = Brushes.Red;
}
DataGridHelper
static class DataGridHelper
{
static public DataGridCell GetCell(DataGrid dg, int row, int column)
{
DataGridRow rowContainer = GetRow(dg, row);
if (rowContainer != null)
{
DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
// try to get the cell but it may possibly be virtualized
DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
if (cell == null)
{
// now try to bring into view and retreive the cell
dg.ScrollIntoView(rowContainer, dg.Columns[column]);
cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
}
return cell;
}
return null;
}
static public DataGridRow GetRow(DataGrid dg, int index)
{
DataGridRow row = (DataGridRow)dg.ItemContainerGenerator.ContainerFromIndex(index);
if (row == null)
{
// may be virtualized, bring into view and try again
dg.ScrollIntoView(dg.Items[index]);
row = (DataGridRow)dg.ItemContainerGenerator.ContainerFromIndex(index);
}
return row;
}
static T GetVisualChild<T>(Visual parent) where T : Visual
{
T child = default(T);
int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < numVisuals; i++)
{
Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
child = v as T;
if (child == null)
{
child = GetVisualChild<T>(v);
}
if (child != null)
{
break;
}
}
return child;
}
}
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