DxTreeList.SelectRow(Int32, Boolean) Method

Selects or deselects a row with the specified visible index.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public void SelectRow(
    int visibleIndex,
    bool selected = true
)

Parameters

Name	Type	Description
visibleIndex	Int32	The row’s visible index.

Optional Parameters

Name	Type	Default	Description
selected	Boolean	True	true to select the row; false to deselect the row.

Remarks

The following methods allow you to manage TreeList selection:

• SelectRow (DeselectRow)
• SelectRows (DeselectRows)
• SelectDataItem (DeselectDataItem)
• SelectDataItems (DeselectDataItems)
• SelectAllOnPage (DeselectAllOnPage)
• SelectAllAsync (DeselectAllAsync)
• ClearSelection

Pass a row’s visible index to the SelectRow method to select that row. The method’s behavior depends on the SelectionMode property value:

• In multiple selection mode, the method keeps the previously selected rows and adds the specified row to selection. To access data items that correspond to selected rows, implement two-way binding for the SelectedDataItems property or handle the SelectedDataItemsChanged event.
• In single selection mode, the method changes selection to the specified row. To access a data item that corresponds to the selected row, implement two-way binding for the SelectedDataItem property or handle the SelectedDataItemChanged event.

Note

Rows that are filtered out and child rows of collapsed items do not have visible indexes. You cannot change the selection state of such rows with DeselectRow and SelectRow methods.

When the TreeList is bound to the GridDevExtremeDataSource or loads data on demand, call the WaitForRemoteSourceRowLoadAsync(Int32) method before you execute the SelectRow method to ensure that the specified data row is loaded.

You can deselect a row with the specified visible index in the following ways:

• Call the DeselectRow(Int32) method.
• Call the SelectRow method and pass false as the second parameter.

Tip

When you call the SelectRow or DeselectRow method, the component sends a callback and redraws the TreeList. If you select or deselect multiple rows, for instance, in a cycle, it can reduce overall performance. Call the SelectRows or DeselectRows method instead to avoid unnecessary callbacks and redraws.

The following example selects and deselects the first row:

Razor

@inject EmployeeTaskService EmployeeTaskService

<style>
    .my-button {
        width: 200px;
    }
</style>

<DxTreeList @ref="MyTreeList"
            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>

<DxButton Click="() => MyTreeList.SelectRow(0)" CssClass="my-button" Text="Select First Row" />
<DxButton Click="() => MyTreeList.DeselectRow(0)" CssClass="my-button" Text="Deselect First Row" />

@code {
    List<EmployeeTask> TreeListData { get; set; }
    IReadOnlyList<object> SelectedDataItems { get; set; }
    ITreeList MyTreeList { get; set; }

    protected override void OnInitialized() {
        TreeListData = EmployeeTaskService.GenerateData();
    }
}

EmployeeTask.cs

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;
    }
}

EmployeeTaskService.cs

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))
        };
    }
}

Program.cs

// ...
builder.Services.AddSingleton<EmployeeTaskService>();

For more information about selection in the TreeList component, refer to the following topic: Selection and Focus in Blazor TreeList.

Implements

SelectRow(Int32, Boolean)

SelectRow(Int32, Boolean)