Blazor List Overview

    The Ignite UI for Blazor List element is extremely useful when presenting a group of items. You can create a simple list of textual items, or a more complex one, containing an array of different layout elements. The IgbList component displays rows of items and supports one or more headers as well. Each list item is completely templatable and will support any valid HTML or other components.

    Blazor List Example

    The following example represents a list populated with contacts with a name and a phone number properties. The IgbList component demonstrated below uses the IgbAvatar and IgbButton elements to enrich the user experience and expose the capabilities of setting avatar picture and buttons for text and call actions.

    Usage

    At its core the list web component allows you to easily display a vertical list of items.

    Before using the IgbList, you need to register it as follows:

    // in Program.cs file

builder.Services.AddIgniteUIBlazor(typeof(IgbListModule));

    You will also need to link an additional CSS file to apply the styling to the IgbList component. The following needs to be placed in the wwwroot/index.html file in a Blazor Web Assembly project or the Pages/_Host.cshtml file in a Blazor Server project:

    <link href="_content/IgniteUI.Blazor/themes/light/bootstrap.css" rel="stylesheet" />

    For a complete introduction to the Ignite UI for Blazor, read the Getting Started topic.

    Add List Items

    Now, we can add the following code to get a simple list of items:

    <IgbList>
    <IgbListHeader>Header</IgbListHeader>
    <IgbListItem>
        <h2 slot="title">Item 1</h2>
    </IgbListItem>
    <IgbListItem>
        <h2 slot="title">Item 2</h2>
    </IgbListItem>
    <IgbListItem>
        <h2 slot="title">Item 3</h2>
    </IgbListItem>
</IgbList>

    If all went well, you should see the following in your browser:

    Let's up our game a bit and enhance our list items. Say we want to create a list of contacts with a name and a phone number displayed under the name. To achieve that we can use some of the slots that come with the list items as demonstrated in the next example:

    <IgbList>
    <IgbListHeader>
        <h1>Contacts</h1>
    </IgbListHeader>
    <IgbListItem>
        <h2 slot="title">Terrance Orta</h2>
        <span slot="subtitle">770-504-2217</span>
    </IgbListItem>
    <IgbListItem>
        <h2 slot="title">Richard Mahoney</h2>
        <span slot="subtitle">423-676-2869</span>
    </IgbListItem>
    <IgbListItem>
        <h2 slot="title">Donna Price</h2>
        <span slot="subtitle">859-496-2817</span>
    </IgbListItem>
</IgbList>

    After implementing the above code, our list component should now look like the following:

    Adding Avatar and Buttons

    We can use some of our other components in conjunction with the IgbList component to enrich the experience and add some functionality. We can have a nice picture avatar to the left of the name and phone values. Additionally, we can add some buttons to the right of them to allow the user to text and call contacts, so let's update our contacts list component to show the avatar and the buttons. We can do that by using some of the list item's slots.

    <IgbList>
    <IgbListHeader>
        <h1>Contacts</h1>
    </IgbListHeader>
    <IgbListItem>
        <IgbAvatar slot="start" src="https://static.infragistics.com/xplatform/images/avatars/8.jpg" Shape="@AvatarShape.Circle"/>
        <h2 slot="title">Terrance Orta</h2>
        <span slot="subtitle">770-504-2217</span>
        <IgbButton slot="end" Variant="@ButtonVariant.Outlined">Text</IgbButton>
        <IgbButton slot="end" Variant="@ButtonVariant.Outlined">Call</IgbButton>
    </IgbListItem>
    <IgbListItem>
        <IgbAvatar slot="start" src="https://static.infragistics.com/xplatform/images/avatars/17.jpg" Shape="@AvatarShape.Circle"/>
        <h2 slot="title">Richard Mahoney</h2>
        <span slot="subtitle">423-676-2869</span>
        <IgbButton slot="end" Variant="@ButtonVariant.Outlined">Text</IgbButton>
        <IgbButton slot="end" Variant="@ButtonVariant.Outlined">Call</IgbButton>
    </IgbListItem>
    <IgbListItem>
        <IgbAvatar slot="start" src="https://static.infragistics.com/xplatform/images/avatars/9.jpg" Shape="@AvatarShape.Circle"/>
        <h2 slot="title">Donna Price</h2>
        <span slot="subtitle">859-496-2817</span>
        <IgbButton slot="end" Variant="@ButtonVariant.Outlined">Text</IgbButton>
        <IgbButton slot="end" Variant="@ButtonVariant.Outlined">Call</IgbButton>
    </IgbListItem>
</IgbList>

    The start slot is meant to be used for adding some kind of media before all other content of our list items. The target element, in our case the IgbAvatar component, will also be provided with a default position and spacing.

    The end slot is meant to be used for list items that have some kind of action or metadata, represented, for example, by a switch, a button, a checkbox, etc. We will use IgbButton components.

    Let's also allow the user to change the size of the list using the --ig-size CSS variable. We will add some radio buttons to display all size values. This way whenever one gets selected, we will change the size of the list.

    <IgbRadioGroup Alignment="@RadioGroupAlignment.Horizontal">
    <IgbRadio Value="Small" label-position="after" Change="OnRadioOptionClick">Small</IgbRadio>
    <IgbRadio Value="Medium" label-position="after" Change="OnRadioOptionClick">Medium</IgbRadio>
    <IgbRadio Value="Large" label-position="after" Checked="true" Change="OnRadioOptionClick">Large</IgbRadio>
</IgbRadioGroup>

<IgbList style="margin-top: 10px;" Size="@ListSize" />

@code {
    public SizableComponentSize ListSize { get; set; }

    public void OnRadioOptionClick(IgbComponentBoolValueChangedEventArgs e)
    {
        IgbRadio radio = e.Parent as IgbRadio;
        switch (radio.Value)
        {
            case "Small":
                {
                    this.ListSize = SizableComponentSize.Small;
                    break;
                }
            case "Medium":
                {
                    this.ListSize = SizableComponentSize.Medium;
                    break;
                }
            case "Large":
                {
                    this.ListSize = SizableComponentSize.Large;
                    break;
                }
        }
    }
}

    The result of implementing the above code should look like the following:

    Styling

    You can change the appearance of our list, by using some of the exposed CSS parts - title, subtitle and end.

    igc-list-header {
    font-size: 20px;
    font-weight: 700;
    color: #3f51b5;
}

igc-list-item::part(title) {
    font-size: 18px;
    color: #3f51b5;
}

igc-list-item::part(subtitle) {
    color: #0099ff;
}

igc-list-item::part(end) {
    --ig-secondary-500: 230,48%,47%;
}

    In this article we covered a lot of ground with the IgbList component. First, we created a simple list with text items. Then, we created a list of contact items and added functionality to them by using some additional Ignite UI for Blazor components, like the IgbAvatar and IgbButton. Finally, we changed the component's appearance through the exposed CSS parts.

    API References

    Additional Resources