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Tooltip in Grid


Product Grid for Blazor,
Tooltip for Blazor


This KB article answers the following question:

  • How to add Tooltips for elements in a Grid column?
  • How to load Tooltip content on demand?


  1. Use a Grid column (cell) template to wrap the cell content in a <span> or <div> with some CSS class.
  2. Use the TargetSelector of the Telerik UI for Blazor Tooltip to attach it to the <span>.
  3. Use the Tooltip's Template and its context to load Data on demand.

Using a Tooltip in the Grid

<p>This example shows how to load content on demand for a tooltip that targets elements inside a Grid. Hover over an employee name.</p>

<TelerikGrid Data="@GridData"
        <GridColumn Field="@(nameof(Employee.Id))" Width="120px" />
        <GridColumn Field="@(nameof(Employee.Name))" Title="Employee Name">
                    Employee employee = (Employee)context;
                    <span data-employeeId="@employee.Id" class="tooltip-target">@employee.Name</span>
        <GridColumn Field="@(nameof(Employee.Team))" Title="Team" />

<TelerikTooltip TargetSelector=".tooltip-target"
                Width="250px" Height="250px"
    <Template Context="ttipContext">
        <h6>Employee Details</h6>
        <hr />
            // in a real app, add defensive checks here or extract into a separate component
            // the key names is the data attribute, lowercase
            int EmployeeId = int.Parse(ttipContext.DataAttributes?["employeeid"] ?? string.Empty);

            var EmployeeDetailsData = GetEmplyeeDetails(EmployeeId);

                <p><strong>Name</strong>: @EmployeeDetailsData.Name</p>
                <p><strong>Team</strong>: @EmployeeDetailsData.Team</p>
                <p><strong>Salary</strong>: $@EmployeeDetailsData.Salary</p>
                <p><strong>Hire date</strong>: @EmployeeDetailsData.HireDate.ToShortDateString()</p>
                <p><strong>Working on</strong>: @EmployeeDetailsData.ActiveProjects projects</p>
                <p><strong>Data loaded at</strong>: @DateTime.Now.ToString("HH:mm:ss")</p>

@code {
    private List<Employee> GridData { get; set; } = new();

    // This shows that the Tooltip will work even if the Grid is bound after the Tooltip is initialized.
    protected override async Task OnAfterRenderAsync(bool firstRender)
        if (firstRender)
            GridData = await GetEmployees();

    private async Task<List<Employee>> GetEmployees()
        if (GridData == null || !GridData.Any())
            GridData = Enumerable.Range(1, 90).Select(x => new Employee
                Id = x,
                Name = "name " + x,
                Team = "team " + x % 5,

        return await Task.FromResult(GridData);

    private Employee GetEmplyeeDetails(int employeeId)
        Random rnd = new Random();
        Employee employee = GridData.First(empl => empl.Id == employeeId);
        employee.Salary = rnd.Next(1000, 5000);
        employee.ActiveProjects = rnd.Next(2, 10);
        employee.HireDate = DateTime.Now.AddYears(-rnd.Next(1, 10)).AddMonths(-rnd.Next(0, 10)).AddDays(-rnd.Next(0, 10));

        return employee;

    public class Employee
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
        public string Team { get; set; } = string.Empty;
        public DateTime HireDate { get; set; }
        public int ActiveProjects { get; set; }
        public decimal Salary { get; set; }
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