DxPieChart<T>.ShowTooltip(T, String) Method

Shows the tooltip for the specified series point.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.1.dll

NuGet Package: DevExpress.Blazor

Declaration

public void ShowTooltip(
    T point,
    string seriesName
)

Parameters

Name	Type	Description
point	T	The series point for which the tooltip is shown.
seriesName	String	The series name.

Remarks

Add a DxChartTooltip object to chart markup and set the DxChartTooltip.Enabled property to true to enable tooltip functionality.

DxPieChart allows you to change tooltip visibility in code. Call ShowTooltip method overloads to show the tooltip for the specified series point. To hide the tooltip, call the HideTooltip() method.

When you call ShowTooltip method overloads, DxPieChart raises the TooltipShowing event. In the event handler, you can get information about the tooltip and specify whether it should appear.

The following code snippet displays custom Show Tooltip and Hide Tooltip buttons that show and hide the tooltip for the specified series point:

Razor

<DxPieChart Data="@SalesData"
            @ref="@pieChart"
            T="SaleInfo">
    <DxPieChartSeries T="SaleInfo"
                      TArgument="string"
                      TValue="double"
                      ValueField="si => si.Amount"
                      ArgumentField="si => si.Region"
                      SummaryMethod="Enumerable.Sum"
                      Name="Region Sales" />
    <DxPieChartSeries T="SaleInfo"
                      TArgument="string"
                      TValue="double"
                      ValueField="si => si.Amount"
                      ArgumentField="si => si.City"
                      SummaryMethod="Enumerable.Sum"
                      Name="City Sales" />
    <DxChartLegend Position="RelativePosition.Outside"
                   HorizontalAlignment="HorizontalAlignment.Center" />
    <DxChartTooltip Enabled="true" />
</DxPieChart>

<DxButton Text=" Show Tooltip" Click="@OnShowTooltipButtonClick" />
<DxButton Text = "Hide Tooltip" Click="@OnHideTooltipButtonClick" />

@code {
    DxPieChart<SaleInfo> pieChart;
    string seriesName = "City Sales";

    void OnShowTooltipButtonClick() {
        var point = SalesData.Where(x => x.City == "Denver").FirstOrDefault();
        if(point != null)
            // Pass the series name as a parameter
            pieChart.ShowTooltip(point, seriesName);
            // Pass the series index (order) as a parameter
            pieChart.ShowTooltip(point, 1);
    }

    void OnHideTooltipButtonClick() {
        pieChart.HideTooltip();
    }

    IEnumerable<SaleInfo> SalesData;

    protected override async Task OnInitializedAsync() {
        SalesData = await Sales.GetSalesAsync();
    }
}

SalesData.cs

public class Sales {
    static IList<SaleInfo> dataSource;

    public class SaleInfo {
        public int OrderId { get; set; }
        public string Region { get; set; }
        public string Country { get; set; }
        public string City { get; set; }
        public int Amount { get; set; }
        public DateTime Date { get; set; }
    }
    static Sales() {
        CreateDataSource();
    }

    public static Task<IQueryable<SaleInfo>> GetSalesAsync() {
        return Task.FromResult(dataSource.AsQueryable());
    }

    static void CreateDataSource() {
        dataSource = new List<SaleInfo> {
            new SaleInfo {
                OrderId = 10248,
                Region = "North America",
                Country = "United States",
                City = "New York",
                Amount = 1740,
                Date = DateTime.Parse("2017/01/06")
            },
            new SaleInfo {
                OrderId = 10249,
                Region = "North America",
                Country = "United States",
                City = "Los Angeles",
                Amount = 850,
                Date = DateTime.Parse("2017/01/13")
            },
            new SaleInfo {
                OrderId = 10250,
                Region = "North America",
                Country = "United States",
                City = "Denver",
                Amount = 2235,
                Date = DateTime.Parse("2017/01/07")
            },
            new SaleInfo {
                OrderId = 10251,
                Region = "North America",
                Country = "Canada",
                City = "Vancouver",
                Amount = 1965,
                Date = DateTime.Parse("2017/01/03")
            },
            new SaleInfo {
                OrderId = 10252,
                Region = "North America",
                Country = "Canada",
                City = "Edmonton",
                Amount = 880,
                Date = DateTime.Parse("2017/01/10")
            },
            new SaleInfo {
                OrderId = 10253,
                Region = "South America",
                Country = "Brazil",
                City = "Rio de Janeiro",
                Amount = 5260,
                Date = DateTime.Parse("2017/01/17")
            },
            new SaleInfo {
                OrderId = 10254,
                Region = "South America",
                Country = "Argentina",
                City = "Buenos Aires",
                Amount = 2790,
                Date = DateTime.Parse("2017/01/21")
            },
            new SaleInfo {
                OrderId = 10255,
                Region = "South America",
                Country = "Paraguay",
                City = "Asuncion",
                Amount = 3140,
                Date = DateTime.Parse("2017/01/01")
            },
            new SaleInfo {
                OrderId = 10256,
                Region = "Europe",
                Country = "United Kingdom",
                City = "London",
                Amount = 6175,
                Date = DateTime.Parse("2017/01/24")
            },
            new SaleInfo {
                OrderId = 10257,
                Region = "Europe",
                Country = "Germany",
                City = "Berlin",
                Amount = 4575,
                Date = DateTime.Parse("2017/01/11")
            },
        };
    }
}