How to change width of Pivot Row and Pivot Column items

private void UpdateGroupingBar()

{

this.pivotGrid1.GroupingBar.Dispatcher.BeginInvoke(() =>

{

if (this.pivotGrid1.GroupingBar.RowHeaderArea != null && this.pivotGrid1.GroupingBar.RowHeaderArea.Items.Count > 1)

{

ItemContainerGenerator containerGenerator = this.pivotGrid1.GroupingBar.RowHeaderArea.ItemContainerGenerator;

for (int i = 0; i < this.pivotGrid1.PivotEngine.PivotRows.Count; i++)

{

PivotItem pivotItem = this.pivotGrid1.PivotEngine.PivotRows[i];

if(pivotItem.FieldMappingName=="Date")

{

ListBoxItem item = containerGenerator.ContainerFromIndex(i) as ListBoxItem;

item.Width = item.ActualWidth - 30;

this.pivotGrid1.InternalGrid.Model.ColumnWidths[i] -=30;

}

}

}

if (this.pivotGrid1.GroupingBar.ColumnHeaderArea != null)

{

this.pivotGrid1.GroupingBar.ColumnHeaderArea.Margin = new Thickness(this.pivotGrid1.GroupingBar.ColumnHeaderArea.Margin.Left - 30,

this.pivotGrid1.GroupingBar.ColumnHeaderArea.Margin.Top,

this.pivotGrid1.GroupingBar.ColumnHeaderArea.Margin.Right,

this.pivotGrid1.GroupingBar.ColumnHeaderArea.Margin.Bottom);

}

});

}