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Visible Columns

The TreeList allows you to programatically hide some of its columns.

In this article:

Basics

To hide a Gantt Tree column set its Visible parameter to false. To hide a column based on a certain condition you can pass, for example, a ternary operator or a method that returns bool - the app can provide an expression according to its logic (like screen size).

Hide a column from the Gantt. Basic example.

@* Hide the Id Gantt Tree column by setting the Visible parameter to false *@

<TelerikGantt Data="@Data"
              Width="900px"
              Height="600px"
              IdField="Id"
              ParentIdField="ParentId">
    <GanttViews>
        <GanttDayView></GanttDayView>
        <GanttWeekView></GanttWeekView>
        <GanttMonthView></GanttMonthView>
        <GanttYearView></GanttYearView>
    </GanttViews>
    <GanttColumns>
        <GanttColumn Field="@nameof(FlatModel.Id)" 
                     Visible="false">
        </GanttColumn>
        <GanttColumn Field="Title"
                     Expandable="true"
                     Width="160px"
                     Title="Task Title">
        </GanttColumn>
        <GanttColumn Field="Start"
                     Width="100px">
        </GanttColumn>
        <GanttColumn Field="End"
                     Width="100px">
        </GanttColumn>
    </GanttColumns>
</TelerikGantt>

@code {
    public DateTime SelectedDate { get; set; } = new DateTime(2019, 11, 11, 6, 0, 0);

    class FlatModel
    {
        public int Id { get; set; }
        public int? ParentId { get; set; }
        public string Title { get; set; }
        public double PercentComplete { get; set; }
        public DateTime Start { get; set; }
        public DateTime End { get; set; }
    }

    public int LastId { get; set; } = 1;
    List<FlatModel> Data { get; set; }

    protected override void OnInitialized()
    {
        Data = new List<FlatModel>();
        var random = new Random();

        for (int i = 1; i < 6; i++)
        {
            var newItem = new FlatModel()
            {
                Id = LastId,
                Title = "Employee  " + i.ToString(),
                Start = new DateTime(2020, 12, 6 + i),
                End = new DateTime(2020, 12, 11 + i),
                PercentComplete = Math.Round(random.NextDouble(), 2)
            };

            Data.Add(newItem);
            var parentId = LastId;
            LastId++;

            for (int j = 0; j < 5; j++)
            {
                Data.Add(new FlatModel()
                {
                    Id = LastId,
                    ParentId = parentId,
                    Title = "    Employee " + i + " : " + j.ToString(),
                    Start = new DateTime(2020, 12, 6 + i + j),
                    End = new DateTime(2020, 12, 7 + i + j),
                    PercentComplete = Math.Round(random.NextDouble(), 2)
                });

                LastId++;
            }
        }

        base.OnInitialized();
    }
}

Notes

Non-visible columns (Visible="false") will have the following behavior:

Examples

In this section you will find the following examples:

Toggle The Visibility Of A Column On Button Click

The application can later the value of the Visible parameter and that will toggle the column.

@* Toggling the visibily of a column keeps its original order in the Gantt Tree. *@

<div>
    <TelerikButton OnClick="@(() => isVisible = !isVisible)">Toggle the visibility of the Id column</TelerikButton>
</div>

<TelerikGantt Data="@Data"
              Width="900px"
              Height="600px"
              IdField="Id"
              ParentIdField="ParentId">
    <GanttViews>
        <GanttDayView></GanttDayView>
        <GanttWeekView></GanttWeekView>
        <GanttMonthView></GanttMonthView>
        <GanttYearView></GanttYearView>
    </GanttViews>
    <GanttColumns>
        <GanttColumn Field="@nameof(FlatModel.Id)" 
                     Visible="@isVisible">
        </GanttColumn>
        <GanttColumn Field="Title"
                     Expandable="true"
                     Width="160px"
                     Title="Task Title">
        </GanttColumn>
        <GanttColumn Field="Start"
                     Width="100px">
        </GanttColumn>
        <GanttColumn Field="End"
                     Width="100px">
        </GanttColumn>
    </GanttColumns>
</TelerikGantt>

@code {

    public bool isVisible { get; set; }
    public DateTime SelectedDate { get; set; } = new DateTime(2019, 11, 11, 6, 0, 0);

    class FlatModel
    {
        public int Id { get; set; }
        public int? ParentId { get; set; }
        public string Title { get; set; }
        public double PercentComplete { get; set; }
        public DateTime Start { get; set; }
        public DateTime End { get; set; }
    }

    public int LastId { get; set; } = 1;
    List<FlatModel> Data { get; set; }

    protected override void OnInitialized()
    {
        Data = new List<FlatModel>();
        var random = new Random();

        for (int i = 1; i < 6; i++)
        {
            var newItem = new FlatModel()
            {
                Id = LastId,
                Title = "Employee  " + i.ToString(),
                Start = new DateTime(2020, 12, 6 + i),
                End = new DateTime(2020, 12, 11 + i),
                PercentComplete = Math.Round(random.NextDouble(), 2)
            };

            Data.Add(newItem);
            var parentId = LastId;
            LastId++;

            for (int j = 0; j < 5; j++)
            {
                Data.Add(new FlatModel()
                {
                    Id = LastId,
                    ParentId = parentId,
                    Title = "    Employee " + i + " : " + j.ToString(),
                    Start = new DateTime(2020, 12, 6 + i + j),
                    End = new DateTime(2020, 12, 7 + i + j),
                    PercentComplete = Math.Round(random.NextDouble(), 2)
                });

                LastId++;
            }
        }

        base.OnInitialized();
    }
}

Hide A Gantt Column Based On A Condition

This example shows hiding a column based on a simple condition in its data. You can change it to use other view-model data - such as screen dimensions, user preferences you have stored, or any other logic.

@* The Id column is hidden, because the data for the Gantt Chart contains 1 *@

<TelerikGantt Data="@Data"
              Width="900px"
              Height="600px"
              IdField="Id"
              ParentIdField="ParentId">
    <GanttViews>
        <GanttDayView></GanttDayView>
        <GanttWeekView></GanttWeekView>
        <GanttMonthView></GanttMonthView>
        <GanttYearView></GanttYearView>
    </GanttViews>
    <GanttColumns>
        <GanttColumn Field="@nameof(FlatModel.Id)" 
                     Visible="@((Data.Any(x => x.Id == 1)) ? false : true)">
        </GanttColumn>
        <GanttColumn Field="Title"
                     Expandable="true"
                     Width="160px"
                     Title="Task Title">
        </GanttColumn>
        <GanttColumn Field="Start"
                     Width="100px">
        </GanttColumn>
        <GanttColumn Field="End"
                     Width="100px">
        </GanttColumn>
    </GanttColumns>
</TelerikGantt>

@code {

    public bool isVisible { get; set; }
    public DateTime SelectedDate { get; set; } = new DateTime(2019, 11, 11, 6, 0, 0);

    class FlatModel
    {
        public int Id { get; set; }
        public int? ParentId { get; set; }
        public string Title { get; set; }
        public double PercentComplete { get; set; }
        public DateTime Start { get; set; }
        public DateTime End { get; set; }
    }

    public int LastId { get; set; } = 1;
    List<FlatModel> Data { get; set; }

    protected override void OnInitialized()
    {
        Data = new List<FlatModel>();
        var random = new Random();

        for (int i = 1; i < 6; i++)
        {
            var newItem = new FlatModel()
            {
                Id = LastId,
                Title = "Employee  " + i.ToString(),
                Start = new DateTime(2020, 12, 6 + i),
                End = new DateTime(2020, 12, 11 + i),
                PercentComplete = Math.Round(random.NextDouble(), 2)
            };

            Data.Add(newItem);
            var parentId = LastId;
            LastId++;

            for (int j = 0; j < 5; j++)
            {
                Data.Add(new FlatModel()
                {
                    Id = LastId,
                    ParentId = parentId,
                    Title = "    Employee " + i + " : " + j.ToString(),
                    Start = new DateTime(2020, 12, 6 + i + j),
                    End = new DateTime(2020, 12, 7 + i + j),
                    PercentComplete = Math.Round(random.NextDouble(), 2)
                });

                LastId++;
            }
        }

        base.OnInitialized();
    }
}
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