Edit this page

Programmatic Definition

Each GridTableView object has a GroupByExpressions property. GroupByExpressions is a collection of group expressions (GridGroupByExpression objects).

Each GridGroupByExpression object in this collection defines a set of groups in the corresponding table. At the top of each group of items is a GridGroupHeaderItem, which can display information about the common properties of the group items or aggregate values that summarize the items in the group.

You can set the GroupByExpressions property in the code-behind to specify the grouping for the tables in the grid. When setting GroupByExpressions at runtime.

  1. For each set of groups, generate a new instance of GridGroupByExpression.
  2. For each GridGroupByExpression object, generate instances of GridGroupByField for each field that is used to group data and for each field that provides a value displayed in the group headers.
  3. Set the properties of the GridGroupByField objects to identify the fields they represent and the display properties for those fields. You can set any of the following properties:
    • FieldName specifies the name of a field in the data source (meaningful for items both from the SelectFields and GroupByFields collections)
    • FieldAlias specifies an alias for representing the field's name (meaningful for items from the SelectFields collection only)
    • Aggregate specifies a GridAggregateFunction value. This property is only for fields displayed in the group header (meaningful for items from the SelectFields collection only)
    • HeaderText specifies the name to use for the field when it appears in the group header and in the group panel (meaningful for items from the SelectFields collection only)
    • HeaderValueSeparator specifies a string that appears in the group header between the header text and the value (or aggregated value) - meaningful for items from the SelectFields collection only
    • FormatString specifies a format string for formatting field values when they appear in the group header (meaningful for items from the SelectFields collection only)
    • SortOrder specifies how group values are sorted. Its value can be "Ascending" or "Descending" (meaningful for items from the GroupByFields collection only)
  4. Add the GridGroupByField objects that represent fields in the group header to the SelectFields collection. Add GridGroupByField objects that represent how the data is grouped to the GroupbyFields collection.
  5. Add the GridGroupByExpression object to the GroupByExpressions collection of the MasterTableView or detail GridTableView.
caution

Note that a FieldAlias for the GroupByFields should not be set as it can cause unexpected behavior. An alias can only be set for the SelectFields .

GridGroupByExpression expression = new GridGroupByExpression();
GridGroupByField gridGroupByField = new GridGroupByField();
// SelectFields values (appear in header)
gridGroupByField = new GridGroupByField();
gridGroupByField.FieldName = "EmployeeID";
gridGroupByField.HeaderText = "Employee";
gridGroupByField.HeaderValueSeparator = " for current group: ";
gridGroupByField.FormatString = "<strong>{0}</strong>";
expression.SelectFields.Add(gridGroupByField);
gridGroupByField = new GridGroupByField();
gridGroupByField.FieldName = "Freight";
gridGroupByField.HeaderText = "Total shipping cost is ";
gridGroupByField.HeaderValueSeparator = "";
gridGroupByField.FormatString = "<strong>{0:0.00}</strong>";
gridGroupByField.Aggregate = GridAggregateFunction.Sum;
expression.SelectFields.Add(gridGroupByField);
//GroupByFields values    (group data)
gridGroupByField = new GridGroupByField();
gridGroupByField.FieldName = "EmployeeID";
expression.GroupByFields.Add(gridGroupByField);
tableViewOrders.GroupByExpressions.Add(expression);
Dim expression As GridGroupByExpression = New GridGroupByExpression
Dim gridGroupByField As GridGroupByField = New GridGroupByField
'SelectFields values (appear in header)
gridGroupByField = New GridGroupByField
gridGroupByField.FieldName = "EmployeeID"
gridGroupByField.HeaderText = "Employee"
gridGroupByField.HeaderValueSeparator = " for current group: "
gridGroupByField.FormatString = "<strong>{0}</strong>"
expression.SelectFields.Add(gridGroupByField)
gridGroupByField = New GridGroupByField
gridGroupByField.FieldName = "Freight"
gridGroupByField.HeaderText = "Total shipping cost is "
gridGroupByField.HeaderValueSeparator = ""
gridGroupByField.FormatString = "<strong>{0:0.00}</strong>"
gridGroupByField.Aggregate = GridAggregateFunction.Sum
expression.SelectFields.Add(gridGroupByField)
'GroupByFields values (group data)
gridGroupByField = New GridGroupByField
gridGroupByField.FieldName = "EmployeeID"
expression.GroupByFields.Add(gridGroupByField)
tableViewOrders.GroupByExpressions.Add(expression)