blazor-devexpress-dot-blazor-dot-dxtreelist-0fe92bbb.md
Specifies whether users can select and deselect rows by mouse clicks, tap gestures, and keyboard shortcuts.
Namespace : DevExpress.Blazor
Assembly : DevExpress.Blazor.v25.2.dll
NuGet Package : DevExpress.Blazor
[DefaultValue(false)]
[Parameter]
public bool AllowSelectRowByClick { get; set; }
| Type | Default | Description |
|---|---|---|
| Boolean | false |
true to allow users to select and deselect rows by mouse clicks, tap gestures, and keyboard shortcuts; otherwise, false.
|
Set the AllowSelectRowByClick property to true to enable the following user operations:
| Operation | Description |
|---|---|
| Click | Click a row to select it and clear the selection of all other rows. |
| Ctrl+Click | Hold down the Ctrl key and click a row to add/remove the row to/from selection. |
| Shift+Click | Click the first row in a range, hold down the Shift key, and click the last row in the range to select a range of rows. |
| Ctrl+Shift+Click | Hold down the Ctrl key, click the first row in the range, hold down the Shift key, and click the last row in the range to add the range of rows to the selection. |
| Space | Focus a cell in a row and press Space to select the row and clear the selection of all other rows. |
| Tap | Tap a row to select it and clear the selection of all other rows. |
| Long Tap | Tap a row for an extended period of time to add/remove the row to/from selection. |
| Long Tap+Move | Tap a row for an extended period and move the finger to add a range of rows to the current selection. |
The TreeList component uses the key field’s values to identify and compare data items. If your data object has a primary key, assign it to the KeyFieldName property. Otherwise, the TreeList uses standard .NET value equality comparison to identify data items.
The TreeList allows users to select multiple rows simultaneously if the SelectionMode property is set to Multiple (the default value). Implement two-way binding for the SelectedDataItems property to specify and access data items that correspond to selected rows.
The following example allows users to click rows to select them and displays information about selected rows:
@inject EmployeeTaskService EmployeeTaskService
<DxTreeList Data="TreeListData"
KeyFieldName="Id"
ParentKeyFieldName="ParentId"
AllowSelectRowByClick="true"
@bind-SelectedDataItems="@SelectedDataItems">
<Columns>
<DxTreeListDataColumn FieldName="Name" Caption="Task" />
<DxTreeListDataColumn FieldName="EmployeeName" />
<DxTreeListDataColumn FieldName="StartDate" />
<DxTreeListDataColumn FieldName="DueDate" />
</Columns>
</DxTreeList>
<div>
<b>Selected tasks:</b>
@{
if(SelectedDataItems != null)
foreach (var task in SelectedDataItems.Cast<EmployeeTask>()) {
<li>@task.Name</li>
}
}
</div>
@code {
List<EmployeeTask> TreeListData { get; set; }
IReadOnlyList<object> SelectedDataItems { get; set; }
protected override void OnInitialized() {
TreeListData = EmployeeTaskService.GenerateData();
}
}
public class EmployeeTask{
public int Id { get; set; }
public int ParentId { get; set; }
public string Name { get; set; }
public string EmployeeName { get; set; }
public DateTime StartDate { get; set; }
public DateTime DueDate { get; set; }
public EmployeeTask(
int id,
int parentId,
string name,
string employeeName,
DateTime startDate,
DateTime dueDate
)
{
Id = id;
ParentId = parentId;
Name = name;
EmployeeName = employeeName;
StartDate = startDate;
DueDate = dueDate;
}
}
public class EmployeeTaskService {
public List<EmployeeTask> GenerateData() {
return new List<EmployeeTask>() {
new EmployeeTask(1, 0, "Simplify & Clarify Product Messaging", "John Heart", new DateTime(2018, 4, 3), new DateTime(2018, 4, 14)),
new EmployeeTask(2, 1, "Prepare Financial Reports", "Samantha Bright", new DateTime(2018, 4, 3), new DateTime(2018, 4, 7)),
new EmployeeTask(3, 1, "Prepare Marketing Plan", "Arthur Miller", new DateTime(2018, 4, 7), new DateTime(2018, 4, 14)),
new EmployeeTask(4, 0, "Create Action Plan To Improve Customer Engagement", "Robert Reagan", new DateTime(2017, 8, 8), new DateTime(2018, 4, 8)),
new EmployeeTask(5, 4, "Update Personnel Files", "Greta Sims", new DateTime(2017, 8, 8), new DateTime(2017, 10, 18)),
new EmployeeTask(6, 4, "Review Health Insurance Options ", "Brett Wade", new DateTime(2017, 9, 27), new DateTime(2017, 11, 10)),
new EmployeeTask(7, 4, "Choose Between PPO And HMO Health Plan", "Sandra Johnson", new DateTime(2017, 12, 13), new DateTime(2018, 3, 23)),
new EmployeeTask(8, 4, "Update Google Adwords Strategy", "Ed Holmes", new DateTime(2017, 8, 23), new DateTime(2017, 12, 23)),
new EmployeeTask(9, 4, "Create New Brochure Design", "Barb Banks", new DateTime(2018, 1, 3), new DateTime(2018, 3, 14)),
new EmployeeTask(10, 4, "Obtain Price Quote For New Brochure", "Kevin Carter", new DateTime(2018, 2, 1), new DateTime(2018, 3, 15)),
new EmployeeTask(11, 4, "Brochure Design Review", "Cindy Stanwick", new DateTime(2017, 8, 22), new DateTime(2017, 10, 28)),
new EmployeeTask(12, 4, "Review Website Re-Design Strategy", "Sammy Hill", new DateTime(2017, 9, 16), new DateTime(2018, 3, 6)),
new EmployeeTask(13, 4, "Rollout New Website", "Davey Jones", new DateTime(2017, 11, 7), new DateTime(2018, 2, 6)),
new EmployeeTask(14, 4, "Update Sales/Marketing Strategy", "Victor Norris", new DateTime(2017, 12, 13), new DateTime(2018, 4, 2)),
new EmployeeTask(15, 4, "Update Sales/Revenue Report", "Mary Stern", new DateTime(2017, 12, 25), new DateTime(2018, 4, 2)),
new EmployeeTask(16, 4, "Direct Vs Online Sales Comparison Report", "Robin Cosworth", new DateTime(2018, 1, 2), new DateTime(2018, 3, 20)),
new EmployeeTask(17, 4, "Review Sales Report and Approve Modifications", "Kelly Rodriguez", new DateTime(2017, 9, 4), new DateTime(2017, 10, 30)),
new EmployeeTask(18, 4, "Update R&D Strategy", "James Anderson", new DateTime(2017, 11, 13), new DateTime(2017, 12, 4)),
new EmployeeTask(19, 4, "Discuss Updated R&D Strategy", "Antony Remmen", new DateTime(2017, 10, 29), new DateTime(2017, 12, 31)),
new EmployeeTask(20, 4, "Update QA Strategy", "Olivia Peyton", new DateTime(2017, 10, 31), new DateTime(2017, 11, 2)),
new EmployeeTask(21, 4, "Schedule Training Events", "Taylor Riley", new DateTime(2017, 11, 19), new DateTime(2018, 4, 7)),
new EmployeeTask(22, 4, "Approve The Hiring Of John Jeffers", "Amelia Harper", new DateTime(2018, 1, 7), new DateTime(2018, 4, 8)),
new EmployeeTask(23, 0, "Increase Average Subscription Price ", "Wally Hobbs", new DateTime(2017, 8, 9), new DateTime(2017, 9, 13)),
new EmployeeTask(24, 23, "Update Non-Compete Agreements", "Brad Jameson", new DateTime(2017, 8, 9), new DateTime(2017, 9, 3)),
new EmployeeTask(25, 23, "Update Employee Records With New NDA", "Karen Goodson", new DateTime(2017, 8, 23), new DateTime(2018, 9, 10))
};
}
}
// ...
builder.Services.AddSingleton<EmployeeTaskService>();
Set the SelectionMode property to Single to allow users to select only one row at a time. Implement two-way binding for the SelectedDataItem property to specify and access the data item that corresponds to the selected row.
The following example allows users to click a row to select it and displays information about that row:
@inject EmployeeTaskService EmployeeTaskService
<DxTreeList Data="TreeListData"
KeyFieldName="Id"
ParentKeyFieldName="ParentId"
AllowSelectRowByClick="true"
SelectionMode="TreeListSelectionMode.Single"
@bind-SelectedDataItem="@SelectedDataItem">
<Columns>
<DxTreeListDataColumn FieldName="Name" Caption="Task" />
<DxTreeListDataColumn FieldName="EmployeeName" />
<DxTreeListDataColumn FieldName="StartDate" />
<DxTreeListDataColumn FieldName="DueDate" />
</Columns>
</DxTreeList>
<div>
<p><b>Selected task:</b> @((SelectedDataItem as EmployeeTask)?.Name ?? "(none)")</p>
</div>
@code {
List<EmployeeTask> TreeListData { get; set; }
object SelectedDataItem { get; set; }
protected override void OnInitialized() {
TreeListData = EmployeeTaskService.GenerateData();
}
}
public class EmployeeTask{
public int Id { get; set; }
public int ParentId { get; set; }
public string Name { get; set; }
public string EmployeeName { get; set; }
public DateTime StartDate { get; set; }
public DateTime DueDate { get; set; }
public EmployeeTask(
int id,
int parentId,
string name,
string employeeName,
DateTime startDate,
DateTime dueDate
)
{
Id = id;
ParentId = parentId;
Name = name;
EmployeeName = employeeName;
StartDate = startDate;
DueDate = dueDate;
}
}
public class EmployeeTaskService {
public List<EmployeeTask> GenerateData() {
return new List<EmployeeTask>() {
new EmployeeTask(1, 0, "Simplify & Clarify Product Messaging", "John Heart", new DateTime(2018, 4, 3), new DateTime(2018, 4, 14)),
new EmployeeTask(2, 1, "Prepare Financial Reports", "Samantha Bright", new DateTime(2018, 4, 3), new DateTime(2018, 4, 7)),
new EmployeeTask(3, 1, "Prepare Marketing Plan", "Arthur Miller", new DateTime(2018, 4, 7), new DateTime(2018, 4, 14)),
new EmployeeTask(4, 0, "Create Action Plan To Improve Customer Engagement", "Robert Reagan", new DateTime(2017, 8, 8), new DateTime(2018, 4, 8)),
new EmployeeTask(5, 4, "Update Personnel Files", "Greta Sims", new DateTime(2017, 8, 8), new DateTime(2017, 10, 18)),
new EmployeeTask(6, 4, "Review Health Insurance Options ", "Brett Wade", new DateTime(2017, 9, 27), new DateTime(2017, 11, 10)),
new EmployeeTask(7, 4, "Choose Between PPO And HMO Health Plan", "Sandra Johnson", new DateTime(2017, 12, 13), new DateTime(2018, 3, 23)),
new EmployeeTask(8, 4, "Update Google Adwords Strategy", "Ed Holmes", new DateTime(2017, 8, 23), new DateTime(2017, 12, 23)),
new EmployeeTask(9, 4, "Create New Brochure Design", "Barb Banks", new DateTime(2018, 1, 3), new DateTime(2018, 3, 14)),
new EmployeeTask(10, 4, "Obtain Price Quote For New Brochure", "Kevin Carter", new DateTime(2018, 2, 1), new DateTime(2018, 3, 15)),
new EmployeeTask(11, 4, "Brochure Design Review", "Cindy Stanwick", new DateTime(2017, 8, 22), new DateTime(2017, 10, 28)),
new EmployeeTask(12, 4, "Review Website Re-Design Strategy", "Sammy Hill", new DateTime(2017, 9, 16), new DateTime(2018, 3, 6)),
new EmployeeTask(13, 4, "Rollout New Website", "Davey Jones", new DateTime(2017, 11, 7), new DateTime(2018, 2, 6)),
new EmployeeTask(14, 4, "Update Sales/Marketing Strategy", "Victor Norris", new DateTime(2017, 12, 13), new DateTime(2018, 4, 2)),
new EmployeeTask(15, 4, "Update Sales/Revenue Report", "Mary Stern", new DateTime(2017, 12, 25), new DateTime(2018, 4, 2)),
new EmployeeTask(16, 4, "Direct Vs Online Sales Comparison Report", "Robin Cosworth", new DateTime(2018, 1, 2), new DateTime(2018, 3, 20)),
new EmployeeTask(17, 4, "Review Sales Report and Approve Modifications", "Kelly Rodriguez", new DateTime(2017, 9, 4), new DateTime(2017, 10, 30)),
new EmployeeTask(18, 4, "Update R&D Strategy", "James Anderson", new DateTime(2017, 11, 13), new DateTime(2017, 12, 4)),
new EmployeeTask(19, 4, "Discuss Updated R&D Strategy", "Antony Remmen", new DateTime(2017, 10, 29), new DateTime(2017, 12, 31)),
new EmployeeTask(20, 4, "Update QA Strategy", "Olivia Peyton", new DateTime(2017, 10, 31), new DateTime(2017, 11, 2)),
new EmployeeTask(21, 4, "Schedule Training Events", "Taylor Riley", new DateTime(2017, 11, 19), new DateTime(2018, 4, 7)),
new EmployeeTask(22, 4, "Approve The Hiring Of John Jeffers", "Amelia Harper", new DateTime(2018, 1, 7), new DateTime(2018, 4, 8)),
new EmployeeTask(23, 0, "Increase Average Subscription Price ", "Wally Hobbs", new DateTime(2017, 8, 9), new DateTime(2017, 9, 13)),
new EmployeeTask(24, 23, "Update Non-Compete Agreements", "Brad Jameson", new DateTime(2017, 8, 9), new DateTime(2017, 9, 3)),
new EmployeeTask(25, 23, "Update Employee Records With New NDA", "Karen Goodson", new DateTime(2017, 8, 23), new DateTime(2018, 9, 10))
};
}
}
// ...
builder.Services.AddSingleton<EmployeeTaskService>();
You can also display a column that allows users to select and deselect rows. To do this, declare a DxTreeListSelectionColumn object in the Columns template. This column contains checkboxes in multiple selection mode and radio buttons in single selection mode. See the DxTreeListSelectionColumn class description for additional information.
You can call the Select* and Deselect* methods to add/remove rows to/from the selection. Refer to the TreeList’s member table for the list of available methods.
For additional information about selection in the TreeList component, refer to the following topic: Selection and Focus in Blazor TreeList.
See Also