Iterate Through Rows and Cells in Code
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This topic demonstrates how to access data items one by one. Refer to the Processing Group Rows topic for information on how to process group rows.
Iterate Through Rows
The GridControl identifies data rows by their handles or visible indexes. The DataControlBase.VisibleRowCount property returns the total number of visible group and data rows. To iterate through rows, use a counter from 0 to the value of the DataControlBase.VisibleRowCount property. In this code sample, we use the GridControl.GetRowHandleByVisibleIndex method to obtain row handles:
<dxg:GridControl x:Name="grid" ItemsSource="{Binding Source}" .../>
List<int> rowHandles = new List<int>();
for (int i = 0; i < grid.VisibleRowCount; i++) {
int rowHandle = grid.GetRowHandleByVisibleIndex(i);
rowHandles.Add(rowHandle);
}
The DataControlBase.VisibleRowCount property does not consider:
- Rows from collapsed groups
- Rows hidden with filters
- Service rows (Auto Filter Row, New Item Row)
- Rows from detail GridControls
Note
When you display the New Item Row at the bottom of the GridControl, the DataControlBase.VisibleRowCount property considers it as a regular row.
To iterate through collapsed rows in a group, use the GridControl.GetChildRowCount method. This method returns the current count of rows in the group. Create a counter similar to the previous one, and use the GridControl.GetChildRowHandle method to obtain handles of rows in the group. Use the GridControl.IsGroupRowHandle method to check that the row is a group row.
The following example shows how to obtain the handles of all data rows (including rows in collapsed groups) in the View, except rows that are filtered out:
private List<int> GetDataRowHandles() {
List<int> rowHandles = new List<int>();
for (int i = 0; i < grid.VisibleRowCount; i++) {
int rowHandle = grid.GetRowHandleByVisibleIndex(i);
if (grid.IsGroupRowHandle(rowHandle)) {
if (!grid.IsGroupRowExpanded(rowHandle)) {
rowHandles.AddRange(GetDataRowHandlesInGroup(rowHandle));
}
}
else
rowHandles.Add(rowHandle);
}
return rowHandles;
}
private List<int> GetDataRowHandlesInGroup(int groupRowHandle) {
List<int> rowHandles = new List<int>();
for (int i = 0; i < grid.GetChildRowCount(groupRowHandle); i++) {
int rowHandle = grid.GetChildRowHandle(groupRowHandle, i);
if (grid.IsGroupRowHandle(rowHandle)) {
rowHandles.AddRange(GetDataRowHandlesInGroup(rowHandle));
}
else
rowHandles.Add(rowHandle);
}
return rowHandles;
}
Iterate Through Cells
The GridControl defines cells by a row handle and a column object. To iterate through cells, extend the technique described in the Iterate Through Rows section and iterate through the GridControl.Columns or GridViewBase.VisibleColumns / TreeListView.VisibleColumns collection to access visible cells:
for (int i = 0; i < grid.VisibleRowCount; i++) {
int rowHandle = grid.GetRowHandleByVisibleIndex(i);
foreach (var column in grid.Columns) {
var cellValue = grid.GetCellValue(rowHandle, column);
}
}
To iterate through columns in all bands, use the GridControl.Columns or GridViewBase.VisibleColumns collection. To iterate through columns in the band, obtain it from the GridControl.Bands collection and use the GridControlBand.Columns collection property.
Iterate Through Nodes
The TreeListView represents nodes as rows. You can use the techniques listed above to iterate through visible nodes and their cells. Refer to the Iterate Through Nodes topic for more information.
Iterate Through Detail Rows in the Master-Detail GridControl
The GridControl includes the following types of detail descriptors:
Note
The detail GridControl is available only if the master row is expanded.
DataControlDetailDescriptor
To iterate through the detail rows, you need to access detail GridControl‘s instances. Use the technique described in the Iterate Through Rows section and use the GridControl.IsMasterRowExpanded method to check that a master row is expanded. Use the GridControl.GetDetail method to obtain the expanded detail GridControl and iterate through its rows:
Dictionary<int, List<int>> master_detail = new Dictionary<int, List<int>>();
for (int i = 0; i < masterGridControl.VisibleRowCount; i++) {
int rowHandle = masterGridControl.GetRowHandleByVisibleIndex(i);
List<int> details = new List<int>();
master_detail[rowHandle] = details;
if (masterGridControl.IsMasterRowExpanded(rowHandle)) {
var detailGrid = masterGridControl.GetDetail(rowHandle) as GridControl;
for (int j = 0; j < detailGrid.VisibleRowCount; j++) {
int detailRowHandle = detailGrid.GetRowHandleByVisibleIndex(j);
details.Add(detailRowHandle);
}
}
}
Use the DataViewBase.FocusedView property to access the focused detail GridControl and iterate through its rows:
var focusedDetail = masterView.FocusedView as TableView;
if (focusedDetail != null) {
List<int> rowHandles = new List<int>();
for (int i = 0; i < focusedDetail.Grid.VisibleRowCount; i++) {
int rowHandle = focusedDetail.Grid.GetRowHandleByVisibleIndex(i);
rowHandles.Add(rowHandle);
}
}
ContentDetailDescriptor
In the ContentDetailDescriptor, you can only obtain content visible in the GridControl‘s View.
To iterate through the detail rows, you need to access detail GridControl‘s instances. Use the LayoutTreeHelper class to iterate through the master GridControl‘s visual tree and access the detail GridControl‘s rows:
var detailGrids = LayoutTreeHelper.GetVisualChildren(masterGridControl).OfType<GridControl>();
foreach(var detailGrid in detailGrids) {
List<int> rowHandles = new List<int>();
for (int i = 0; i < detailGrid.VisibleRowCount; i++) {
int rowHandle = detailGrid.GetRowHandleByVisibleIndex(i);
rowHandles.Add(rowHandle);
}
}
TabViewDetailDescriptor
The TabViewDetailDescriptor displays different types of details (ContentDetailDescriptor and DataControlDetailDescriptor) in its tabs. The GridControl creates a visual element only for the selected tab. To iterate through detail rows in the tab, use a technique described in the detail descriptor topic.
The GridControl.GetDetail method’s override accepts the DataControlDetailDescriptor objects. Use this override to obtain the GridControl shown in the TabViewDetailDescriptor’s tabs:
<dxg:GridControl.DetailDescriptor>
<dxg:TabViewDetailDescriptor>
<dxg:DataControlDetailDescriptor x:Name="firstDetailDescriptor" ItemsSourceBinding="{Binding Data}">
<dxg:GridControl AutoGenerateColumns="AddNew" x:Name="detailGridControl">
<dxg:GridControl.View>
<dxg:TableView x:Name="detailView"/>
</dxg:GridControl.View>
</dxg:GridControl>
</dxg:DataControlDetailDescriptor>
</dxg:TabViewDetailDescriptor>
</dxg:GridControl.DetailDescriptor>
Dictionary<int, List<int>> master_detail = new Dictionary<int, List<int>>();
for (int i = 0; i < masterGridControl.VisibleRowCount; i++) {
int rowHandle = masterGridControl.GetRowHandleByVisibleIndex(i);
List<int> details = new List<int>();
master_detail[rowHandle] = details;
if (masterGridControl.IsMasterRowExpanded(rowHandle)) {
var detailGrid = masterGridControl.GetDetail(rowHandle, firstDetailDescriptor) as GridControl;
if (detailGrid == null)
return;
for (int j = 0; j < detailGrid.VisibleRowCount; j++) {
int detailRowHandle = detailGrid.GetRowHandleByVisibleIndex(j);
details.Add(detailRowHandle);
}
}
}