How to: Group Data (Runtime Sample)

• Nov 13, 2018
• 2 minutes to read

This document describes how to group Snap list data in code. To learn how to accomplish this task by using the Snap graphical user interface, see the Group Document Data topic.

The method illustrated in this code sample groups Snap list data by proceeding with the following steps.

1. Create a SnapListGroupInfo by passing the required grouping criteria and sort order to the SnapListGroups.CreateSnapListGroupInfo method.
2. Add the created SnapListGroupInfo to the SnapList.Groups collection.
3. To add a group header, call the SnapListGroupInfo.CreateHeader method.
4. To add a group footer, call the SnapListGroupInfo.CreateFooter method.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-generate-a-document-layout-in-code-via-the-snap-application-programming-interface-api-e4781

Form1.cs

using DevExpress.Data;
using DevExpress.Snap.Core.API;
using DevExpress.XtraRichEdit.API.Native;
// ...
        private void GroupList(SnapList list) {
            // Add grouping to the Snap list.
            SnapListGroupInfo group = list.Groups.CreateSnapListGroupInfo(
                new SnapListGroupParam("CategoryID", ColumnSortOrder.Ascending));
            list.Groups.Add(group);

            // Add a group header.
            SnapDocument groupHeader = group.CreateHeader();
            Table headerTable = groupHeader.Tables.Create(groupHeader.Range.End, 1, 1);
            headerTable.SetPreferredWidth(50 * 100, WidthType.FiftiethsOfPercent);
            TableCellCollection groupHeaderCells = headerTable.FirstRow.Cells;
            groupHeader.InsertText(groupHeaderCells[0].ContentRange.End, "Category ID: ");
            groupHeader.CreateSnText(groupHeaderCells[0].ContentRange.End, "CategoryID");

            // Customize the group header formatting.
            groupHeaderCells[0].BackgroundColor = System.Drawing.Color.LightGray;
            groupHeaderCells[0].Borders.Bottom.LineColor = System.Drawing.Color.White;
            groupHeaderCells[0].Borders.Left.LineColor = System.Drawing.Color.White;
            groupHeaderCells[0].Borders.Right.LineColor = System.Drawing.Color.White;
            groupHeaderCells[0].Borders.Top.LineColor = System.Drawing.Color.White;

            // Add a group footer.
            SnapDocument groupFooter = group.CreateFooter();
            Table footerTable = groupFooter.Tables.Create(groupFooter.Range.End, 1, 1);
            footerTable.SetPreferredWidth(50 * 100, WidthType.FiftiethsOfPercent);
            TableCellCollection groupFooterCells = footerTable.FirstRow.Cells;
            groupFooter.InsertText(groupFooterCells[0].ContentRange.End, "Count = ");
            groupFooter.CreateSnText(groupFooterCells[0].ContentRange.End,
                @"CategoryID \sr Group \sf Count");

            // Customize the group footer formatting.
            groupFooterCells[0].BackgroundColor = System.Drawing.Color.LightGray;
            groupFooterCells[0].Borders.Bottom.LineColor = System.Drawing.Color.White;
            groupFooterCells[0].Borders.Left.LineColor = System.Drawing.Color.White;
            groupFooterCells[0].Borders.Right.LineColor = System.Drawing.Color.White;
            groupFooterCells[0].Borders.Top.LineColor = System.Drawing.Color.White;
        }

Form1.vb

Imports DevExpress.Data
Imports DevExpress.Snap.Core.API
Imports DevExpress.XtraRichEdit.API.Native
' ...
        Private Sub GroupList(ByVal list As SnapList)
            ' Add grouping to the Snap list.
            Dim group As SnapListGroupInfo = list.Groups.CreateSnapListGroupInfo(New SnapListGroupParam("CategoryID", ColumnSortOrder.Ascending))
            list.Groups.Add(group)

            ' Add a group header.
            Dim groupHeader As SnapDocument = group.CreateHeader()
            Dim headerTable As Table = groupHeader.Tables.Create(groupHeader.Range.End, 1, 1)
            headerTable.SetPreferredWidth(50 * 100, WidthType.FiftiethsOfPercent)
            Dim groupHeaderCells As TableCellCollection = headerTable.FirstRow.Cells
            groupHeader.InsertText(groupHeaderCells(0).ContentRange.End, "Category ID: ")
            groupHeader.CreateSnText(groupHeaderCells(0).ContentRange.End, "CategoryID")

            ' Customize the group header formatting.
            groupHeaderCells(0).BackgroundColor = System.Drawing.Color.LightGray
            groupHeaderCells(0).Borders.Bottom.LineColor = System.Drawing.Color.White
            groupHeaderCells(0).Borders.Left.LineColor = System.Drawing.Color.White
            groupHeaderCells(0).Borders.Right.LineColor = System.Drawing.Color.White
            groupHeaderCells(0).Borders.Top.LineColor = System.Drawing.Color.White

            ' Add a group footer.
            Dim groupFooter As SnapDocument = group.CreateFooter()
            Dim footerTable As Table = groupFooter.Tables.Create(groupFooter.Range.End, 1, 1)
            footerTable.SetPreferredWidth(50 * 100, WidthType.FiftiethsOfPercent)
            Dim groupFooterCells As TableCellCollection = footerTable.FirstRow.Cells
            groupFooter.InsertText(groupFooterCells(0).ContentRange.End, "Count = ")
            groupFooter.CreateSnText(groupFooterCells(0).ContentRange.End, "CategoryID \sr Group \sf Count")

            ' Customize the group footer formatting.
            groupFooterCells(0).BackgroundColor = System.Drawing.Color.LightGray
            groupFooterCells(0).Borders.Bottom.LineColor = System.Drawing.Color.White
            groupFooterCells(0).Borders.Left.LineColor = System.Drawing.Color.White
            groupFooterCells(0).Borders.Right.LineColor = System.Drawing.Color.White
            groupFooterCells(0).Borders.Top.LineColor = System.Drawing.Color.White
        End Sub