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Blazor Bar Chart

A Blazor Bootstrap bar chart component is used to represent data values as vertical bars. It is sometimes used to show trend data and to compare multiple data sets side by side.

Blazor Chart Component - Blazor Bar Chart

Parameters

NameTypeDefaultRequiredDescriptionAdded Version
Heightint?nullGets or sets chart container height.1.0.0
HeightUnitUnitUnit.PxGets or sets chart container height unit of measure.1.0.0
Widthint?nullGets or sets chart container width.1.0.0
WidthUnitUnitUnit.PxGets or sets chart container width unit of measure.1.0.0

Methods

NameReturn typeDescriptionAdded Version
AddDataAsync(ChartData chartData, string dataLabel, IChartDatasetData data)Task<ChartData>Adds data to chart.1.10.0
AddDataAsync(ChartData chartData, string dataLabel, List<IChartDatasetData> data)Task<ChartData>Adds dataset to chart.1.10.0
AddDatasetAsync(ChartData chartData, IChartDataset chartDataset, IChartOptions chartOptions)Task<ChartData>Adds dataset to chart.1.10.0
InitializeAsync(ChartData chartData, IChartOptions chartOptions, string[]? plugins = null)TaskInitialize the chat.1.0.0
ResizeAsync(int width, int height, Unit widthUnit = Unit.Px, Unit heightUnit = Unit.Px)TaskResize the chart.1.0.0
UpdateAsync(ChartData chartData, IChartOptions chartOptions)TaskUpdate the chart.1.0.0

ChartData Members

Property NameTypeDefaultRequiredDescriptionAdded Version
DatasetsList<IChartDataset>null✔️Gets or sets the Datasets.1.0.0
LabelsList<string>null✔️Gets or sets the Labels.1.0.0

BarChartDataset Members

info

BarChartDataset implements IChartDataset.

Property NameTypeDefaultRequiredDescriptionAdded Version
BackgroundColorList<string>nullGet or sets the BackgroundColor.1.0.0
BarPercentagedouble0.8Percent (0-1) of the available width each bar should be within the category width. 1.0 will take the whole category width and put the bars right next to each other.1.0.0
BorderColorList<string>nullGet or sets the BorderColor.1.0.0
BorderRadiusint0Border radius.1.0.0
BorderWidthList<double>nullGet or sets the BorderWidth.1.0.0
CategoryPercentagedouble0.8Percent (0-1) of the available width each category should be within the sample width.1.0.0
ClipstringnullHow to clip relative to chartArea. Positive value allows overflow, negative value clips that many pixels inside chartArea. 0 = clip at chartArea. Clipping can also be configured per side: clip: {left: 5, top: false, right: -2, bottom: 0}1.0.0
DatalabelsBarChartDatasetDataLabelsGet or sets the data labels
DataList<double>nullGet or sets the Data.1.0.0
HiddenboolfalseConfigures the visibility state of the dataset. Set it to true, to hide the dataset from the chart.1.0.0
HoverBackgroundColorList<string>null✔️Get or sets the HoverBackgroundColor.1.0.0
HoverBorderColorList<string>null✔️Get or sets the HoverBorderColor.1.0.0
HoverBorderWidthList<double>null✔️Get or sets the HoverBorderWidth.1.0.0
LabelstringnullThe label for the dataset which appears in the legend and tooltips.1.0.0
Typestringnull✔️Get or sets the chart type.1.0.0
XAxisIDstringnullThe ID of the x axis to plot this dataset on.1.0.0
YAxisIDstringnullThe ID of the y axis to plot this dataset on.1.0.0

BarChartDatasetDataLabels Members

Property NameTypeDefaultRequiredDescriptionAdded Version
Alignstring?centerGets or sets the align.1.10.2
Anchorstring?centerGets or sets the anchor.1.10.2

BarChartOptions Members

info

BarChartOptions implements ChartOptions.

Property NameTypeDefaultRequiredDescriptionAdded Version
IndexAxisstringxThe base axis of the chart. 'x' for vertical charts and 'y' for horizontal charts.1.0.0
InteractionInteractionGets or sets the Interaction.1.0.0
LayoutChartLayoutGets or sets the ChartLayout.1.0.0
Localestring?Gets or sets the locale. By default, the chart is using the default locale of the platform which is running on.1.10.0
PluginsBarChartPluginsGets or sets the Plugins.1.10.2
ResponsiveboolfalseGets or sets the Responsive.1.0.0
ScalesScalesGets or sets the Scales.1.0.0

Examples

Prerequisites

Refer to the getting started guide for setting up charts.

How it works

In the following example, a categorical 12-color palette is used.

tip

For data visualization, you can use the predefined palettes ColorBuilder.CategoricalTwelveColors for a 12-color palette and ColorBuilder.CategoricalSixColors for a 6-color palette. These palettes offer a range of distinct and visually appealing colors that can be applied to represent different categories or data elements in your visualizations.

Blazor Bootstrap: Bar Chart Component - How it works
<BarChart @ref="barChart" Width="800" Class="mb-4" />

<Button Type="ButtonType.Button" Color="ButtonColor.Primary" Size="Size.Small" @onclick="async () => await RandomizeAsync()"> Randomize </Button>
<Button Type="ButtonType.Button" Color="ButtonColor.Primary" Size="Size.Small" @onclick="async () => await AddDatasetAsync()"> Add Dataset </Button>
<Button Type="ButtonType.Button" Color="ButtonColor.Primary" Size="Size.Small" @onclick="async () => await AddDataAsync()">Add Data</Button>
<Button Type="ButtonType.Button" Color="ButtonColor.Primary" Size="Size.Small" @onclick="async () => await ShowHorizontalBarChartAsync()">Horizontal Bar Chart</Button>
<Button Type="ButtonType.Button" Color="ButtonColor.Primary" Size="Size.Small" @onclick="async () => await ShowVerticalBarChartAsync()">Vertical Bar Chart</Button>
@code {
private BarChart barChart = default!;
private BarChartOptions barChartOptions = default!;
private ChartData chartData = default!;

private int datasetsCount = 0;
private int labelsCount = 0;
private string[] months = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" };
private Random random = new();

protected override void OnInitialized()
{
chartData = new ChartData { Labels = GetDefaultDataLabels(6), Datasets = GetDefaultDataSets(3) };
barChartOptions = new BarChartOptions { Responsive = true, Interaction = new Interaction { Mode = InteractionMode.Index } };
}

protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
await barChart.InitializeAsync(chartData, barChartOptions);
}
await base.OnAfterRenderAsync(firstRender);
}

private async Task RandomizeAsync()
{
if (chartData is null || chartData.Datasets is null || !chartData.Datasets.Any()) return;

var newDatasets = new List<IChartDataset>();

foreach (var dataset in chartData.Datasets)
{
if (dataset is BarChartDataset barChartDataset
&& barChartDataset is not null
&& barChartDataset.Data is not null)
{
var count = barChartDataset.Data.Count;

var newData = new List<double>();
for (var i = 0; i < count; i++)
{
newData.Add(random.Next(200));
}

barChartDataset.Data = newData;
newDatasets.Add(barChartDataset);
}
}

chartData.Datasets = newDatasets;

await barChart.UpdateAsync(chartData, barChartOptions);
}

private async Task AddDatasetAsync()
{
if (chartData is null || chartData.Datasets is null) return;

if (datasetsCount >= 12)
return;

var chartDataset = GetRandomBarChartDataset();
chartData = await barChart.AddDatasetAsync(chartData, chartDataset, barChartOptions);
}

private async Task AddDataAsync()
{
if (chartData is null || chartData.Datasets is null)
return;

if (labelsCount >= 12)
return;

var data = new List<IChartDatasetData>();
foreach (var dataset in chartData.Datasets)
{
if (dataset is BarChartDataset barChartDataset)
data.Add(new BarChartDatasetData(barChartDataset.Label, random.Next(200)));
}

chartData = await barChart.AddDataAsync(chartData, GetNextDataLabel(), data);
}

private async Task ShowHorizontalBarChartAsync()
{
barChartOptions.IndexAxis = "y";
await barChart.UpdateAsync(chartData, barChartOptions);
}

private async Task ShowVerticalBarChartAsync()
{
barChartOptions.IndexAxis = "x";
await barChart.UpdateAsync(chartData, barChartOptions);
}

#region Data Preparation

private List<IChartDataset> GetDefaultDataSets(int numberOfDatasets)
{
var datasets = new List<IChartDataset>();

for (var index = 0; index < numberOfDatasets; index++)
{
datasets.Add(GetRandomBarChartDataset());
}

return datasets;
}

private BarChartDataset GetRandomBarChartDataset()
{
var c = ColorBuilder.CategoricalTwelveColors[datasetsCount].ToColor();

datasetsCount += 1;

return new BarChartDataset()
{
Label = $"Product {datasetsCount}",
Data = GetRandomData(),
BackgroundColor = new List<string> { c.ToRgbString() },
BorderColor = new List<string> { c.ToRgbString() },
BorderWidth = new List<double> { 0 },
};
}

private List<double> GetRandomData()
{
var data = new List<double>();
for (var index = 0; index < labelsCount; index++)
{
data.Add(random.Next(200));
}

return data;
}

private List<string> GetDefaultDataLabels(int numberOfLabels)
{
var labels = new List<string>();
for (var index = 0; index < numberOfLabels; index++)
{
labels.Add(GetNextDataLabel());
}

return labels;
}

private string GetNextDataLabel()
{
labelsCount += 1;
return months[labelsCount - 1];
}

#endregion Data Preparation
}

See the demo here.

Horizontal bar chart

Blazor Bootstrap: Bar Chart Component - Horizontal bar chart
<BarChart @ref="barChart" Height="300" Class="mb-4" />
@code {
private BarChart barChart = default!;
private BarChartOptions barChartOptions = default!;
private ChartData chartData = default!;

protected override void OnInitialized()
{
var labels = new List<string> { "Chrome", "Firefox", "Safari", "Edge" };
var datasets = new List<IChartDataset>();

var dataset1 = new BarChartDataset()
{
Data = new List<double> { 55000, 15000, 18000, 21000 },
BackgroundColor = new List<string> { ColorBuilder.CategoricalTwelveColors[0] },
BorderColor = new List<string> { ColorBuilder.CategoricalTwelveColors[0] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset1);

chartData = new ChartData {
Labels = labels,
Datasets = datasets };

barChartOptions = new BarChartOptions();
barChartOptions.Responsive = true;
barChartOptions.Interaction = new Interaction { Mode = InteractionMode.Y };
barChartOptions.IndexAxis = "y";

barChartOptions.Scales.X.Title.Text = "Visitors";
barChartOptions.Scales.X.Title.Display = true;

barChartOptions.Scales.Y.Title.Text = "Browser";
barChartOptions.Scales.Y.Title.Display = true;

barChartOptions.Plugins.Legend.Display = false;
}

protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
await barChart.InitializeAsync(chartData, barChartOptions);
}
await base.OnAfterRenderAsync(firstRender);
}
}

See the demo here.

Stacked bar chart

Blazor Bootstrap: Bar Chart Component - Stacked bar chart
<BarChart @ref="barChart" Height="300" Class="mb-4" />
@code {
private BarChart barChart = default!;
private BarChartOptions barChartOptions = default!;
private ChartData chartData = default!;

protected override void OnInitialized()
{
var colors = ColorBuilder.CategoricalTwelveColors;

var labels = new List<string> { "Chrome", "Firefox", "Safari", "Edge" };
var datasets = new List<IChartDataset>();

var dataset1 = new BarChartDataset()
{
Label = "Windows",
Data = new List<double> { 28000, 8000, 2000, 17000 },
BackgroundColor = new List<string> { colors[0] },
BorderColor = new List<string> { colors[0] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset1);

var dataset2 = new BarChartDataset()
{
Label = "macOS",
Data = new List<double> { 8000, 10000, 14000, 8000 },
BackgroundColor = new List<string> { colors[1] },
BorderColor = new List<string> { colors[1] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset2);

var dataset3 = new BarChartDataset()
{
Label = "Other",
Data = new List<double> { 28000, 10000, 14000, 8000 },
BackgroundColor = new List<string> { colors[2] },
BorderColor = new List<string> { colors[2] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset3);

chartData = new ChartData
{
Labels = labels,
Datasets = datasets
};

barChartOptions = new();
barChartOptions.Responsive = true;
barChartOptions.Interaction = new Interaction { Mode = InteractionMode.Y };
barChartOptions.IndexAxis = "y";

barChartOptions.Scales.X.Title.Text = "Visitors";
barChartOptions.Scales.X.Title.Display = true;

barChartOptions.Scales.Y.Title.Text = "Browser";
barChartOptions.Scales.Y.Title.Display = true;

barChartOptions.Scales.X.Stacked = true;
barChartOptions.Scales.Y.Stacked = true;

barChartOptions.Plugins.Title.Text = "Operating system";
barChartOptions.Plugins.Title.Display = true;
}

protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
await barChart.InitializeAsync(chartData, barChartOptions);
}
await base.OnAfterRenderAsync(firstRender);
}
}

See the demo here.

Locale

By default, the chart is using the default locale of the platform on which it is running. In the following example, you will see the chart in the German locale (de_DE).

Blazor Bootstrap: Bar Chart Component - Locale
<BarChart @ref="barChart" Height="300" Class="mb-4" />
@code {
private BarChart barChart = default!;
private BarChartOptions barChartOptions = default!;
private ChartData chartData = default!;

protected override void OnInitialized()
{
var colors = ColorBuilder.CategoricalTwelveColors;

var labels = new List<string> { "Chrome", "Firefox", "Safari", "Edge" };
var datasets = new List<IChartDataset>();

var dataset1 = new BarChartDataset()
{
Label = "Windows",
Data = new List<double> { 28000, 8000, 2000, 17000 },
BackgroundColor = new List<string> { colors[0] },
BorderColor = new List<string> { colors[0] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset1);

var dataset2 = new BarChartDataset()
{
Label = "macOS",
Data = new List<double> { 8000, 10000, 14000, 8000 },
BackgroundColor = new List<string> { colors[1] },
BorderColor = new List<string> { colors[1] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset2);

var dataset3 = new BarChartDataset()
{
Label = "Other",
Data = new List<double> { 28000, 10000, 14000, 8000 },
BackgroundColor = new List<string> { colors[2] },
BorderColor = new List<string> { colors[2] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset3);

chartData = new ChartData
{
Labels = labels,
Datasets = datasets
};

barChartOptions = new();
barChartOptions.Locale = "de-DE";
barChartOptions.Responsive = true;
barChartOptions.Interaction = new Interaction { Mode = InteractionMode.Y };
barChartOptions.IndexAxis = "y";

barChartOptions.Scales.X.Title.Text = "Visitors";
barChartOptions.Scales.X.Title.Display = true;

barChartOptions.Scales.Y.Title.Text = "Browser";
barChartOptions.Scales.Y.Title.Display = true;

barChartOptions.Scales.X.Stacked = true;
barChartOptions.Scales.Y.Stacked = true;

barChartOptions.Plugins.Title.Text = "Operating system";
barChartOptions.Plugins.Title.Display = true;
}

protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
await barChart.InitializeAsync(chartData, barChartOptions);
}
await base.OnAfterRenderAsync(firstRender);
}
}

See the demo here.

Data labels

Blazor Bootstrap: Bar Chart Component - Data labels
<BarChart @ref="barChart" Height="300" Class="mb-4" />
@code {
private BarChart barChart = default!;
private BarChartOptions barChartOptions = default!;
private ChartData chartData = default!;

protected override void OnInitialized()
{
var colors = ColorBuilder.CategoricalTwelveColors;

var labels = new List<string> { "Chrome", "Firefox", "Safari", "Edge" };
var datasets = new List<IChartDataset>();

var dataset1 = new BarChartDataset()
{
Label = "Windows",
Data = new List<double> { 28000, 8000, 2000, 17000 },
BackgroundColor = new List<string> { colors[0] },
BorderColor = new List<string> { colors[0] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset1);

var dataset2 = new BarChartDataset()
{
Label = "macOS",
Data = new List<double> { 8000, 10000, 14000, 8000 },
BackgroundColor = new List<string> { colors[1] },
BorderColor = new List<string> { colors[1] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset2);

var dataset3 = new BarChartDataset()
{
Label = "Other",
Data = new List<double> { 28000, 10000, 14000, 8000 },
BackgroundColor = new List<string> { colors[2] },
BorderColor = new List<string> { colors[2] },
BorderWidth = new List<double> { 0 },
};
datasets.Add(dataset3);

chartData = new ChartData
{
Labels = labels,
Datasets = datasets
};

barChartOptions = new();
barChartOptions.Responsive = true;
barChartOptions.Interaction = new Interaction { Mode = InteractionMode.Y };
barChartOptions.IndexAxis = "y";

barChartOptions.Scales.X.Title.Text = "Visitors";
barChartOptions.Scales.X.Title.Display = true;

barChartOptions.Scales.Y.Title.Text = "Browser";
barChartOptions.Scales.Y.Title.Display = true;

barChartOptions.Scales.X.Stacked = true;
barChartOptions.Scales.Y.Stacked = true;

barChartOptions.Plugins.Title.Text = "Operating system";
barChartOptions.Plugins.Title.Display = true;
}

protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
// pass the plugin name to enable the data labels
await barChart.InitializeAsync(chartData: chartData, chartOptions: barChartOptions, plugins: new string[] { "ChartDataLabels" });
}
await base.OnAfterRenderAsync(firstRender);
}
}

See the demo here.