DxRadio<TValue> Class
An individual radio button that allows you to build radio groups with a custom item layout.
Namespace: DevExpress.Blazor
Assembly: DevExpress.Blazor.v24.2.dll
NuGet Package: DevExpress.Blazor
Declaration
public class DxRadio<TValue> :
RadioBase<TValue, TValue>,
ISynchronizedRadio,
ICheckBoxInternalOwner,
IRequireSelfCascadingType Parameters
| Name | Description |
|---|---|
| TValue | The value type. |
Remarks
The DevExpress Radio Button for Blazor (<DxRadio>) allows you to create individual radio buttons and combine them into groups. A user can select only one button in a group at a time.
Note
As an alternative, you can use the DevExpress Radio Group component (<DxRadioGroup>). The Radio Group component allows you to generate a set of radio buttons based on a collection, while the Radio Button component allows you to create and customize radio buttons individually.
Add a Radio Button to a Project
Follow the steps below to add a Radio Button component to an application:
- Use a DevExpress Project Template to create a new Blazor Server or Blazor WebAssembly application. If you use a Microsoft project template or already have a Blazor project, configure your project to incorporate DevExpress Blazor components.
- Add the
<DxRadio>…</DxRadio>markup to a.razorfile. - Specify a radio button value, the name of a radio group to which the button belongs, and a group value. Customize the radio button as your needs dictate (review instructions below).
.NET 8 and .NET 9 Specifics
Blazor Radio Button does not support static render mode. Enable interactivity to use the component in your application. Refer to the following topic for more details: Enable Interactive Render Mode.
Specify Radio Button Value, Group Name, and Group Value
The main Radio Button API members are listed below.
| API Member | Description |
|---|---|
| Value | Specifies the radio button’s value. |
| GroupName | Specifies the name of a radio group to which the radio button belongs. This property is required. |
| GroupValue | Specifies the value of the selected radio button. You can use the @bind attribute to bind the GroupValue property to a data field. Refer to Two-Way Data Binding. |
The following code snippet creates a simple radio group.
<div role="radiogroup">
@foreach(var priorityLevel in PriorityLevels) {
<DxRadio GroupName="priorities-radio-group"
@bind-GroupValue="@SelectedPriorityLevel"
Value="@priorityLevel">
@priorityLevel
</DxRadio>
}
</div>
@code {
string SelectedPriorityLevel { get; set; } = "normal";
IEnumerable<string> PriorityLevels = new[] { "low", "normal", "urgent", "high" };
}
The following code snippet creates cascading radio groups. One group is visible at first (general-radio-group). The second group (aot-radio-group) appears if a user selects radio button 1 or 2 in the first group.
<fieldset role="radiogroup">
<legend>Are you developing Blazor WebAssembly apps?</legend>
@foreach(var option in GeneralAnswerOptions) {
<DxRadio GroupName="general-radio-group"
@bind-GroupValue="@GeneralAnswer"
Value="@option">
@option
</DxRadio>
}
</fieldset>
@if(AOTGroupVisible) {
<fieldset role="radiogroup">
<legend>Do you expect to enable AOT in your Blazor WebAssembly apps?</legend>
@foreach(var option in AOTAnswerOptions) {
<DxRadio GroupName="aot-radio-group"
@bind-GroupValue="@AOTAnswer"
Value="@option">
@option
</DxRadio>
}
</fieldset>
}
@code {
string GeneralAnswer { get; set; }
string AOTAnswer { get; set; }
bool AOTGroupVisible => !string.IsNullOrEmpty(GeneralAnswer) && GeneralAnswer != GeneralAnswerOptions.Last();
IEnumerable<string> GeneralAnswerOptions = new[] {
"Yes.",
"No, but I plan to develop a WebAssembly app in the near future.",
"No."
};
IEnumerable<string> AOTAnswerOptions = new[] {
"Yes, I already enabled it.",
"Yes, I plan to enable it AOT in my WebAssembly app.",
"No."
};
}
Note
To improve accessibility support, radio buttons must be grouped together in a radiogroup to indicate which ones affect the same value. Refer to the following topic for more information: ARIA: radiogroup role. See code examples above.
Customize Appearance
Use the following properties to customize radio button appearance:
| API Member | Description |
|---|---|
| Alignment | Specifies the position of the radio button’s label relative to the container boundaries. |
| CssClass | Assigns a CSS class to the editor. |
| IconCssClass | Specifies the name of the CSS class applied to the radio button’s icon. |
| LabelPosition | Specifies the position of the button label relative to the clickable circle. |
| LabelWrapMode | Specifies word wrap style for the label. |
The following code snippet changes content position.
<div style="width:400px" role="radiogroup">
@foreach (var priorityLevel in PriorityLevels) {
<DxRadio GroupName="priorities-radio-group"
@bind-GroupValue="@SelectedPriorityLevel"
Value="@priorityLevel"
LabelPosition="LabelPosition.Left"
Alignment="CheckBoxContentAlignment.Right">
@priorityLevel
</DxRadio>
}
</div>
@code {
string SelectedPriorityLevel { get; set; } = "normal";
IEnumerable<string> PriorityLevels = new[] { "low", "normal", "urgent", "high" };
}
The following code snippet applies different styles to radio buttons with different priority levels.
<fieldset role="radiogroup">
@foreach(var priorityLevel in PriorityLevels) {
<DxRadio GroupName="priorities-radio-group"
@bind-GroupValue="@SelectedPriorityLevel"
Value="@priorityLevel"
CssClass="@GetItemCssClass(priorityLevel)">
</DxRadio>
}
</fieldset>
@code {
string SelectedPriorityLevel { get; set; } = "normal";
IEnumerable<string> PriorityLevels = new[] { "low", "normal", "urgent", "high" };
string GetItemCssClass(string priorityLevel) {
var result = $"dx-demo-radio priority-{priorityLevel}";
if(priorityLevel == SelectedPriorityLevel)
result += " dx-demo-radio-selected";
return result;
}
}
Disable Radio Buttons
Radio buttons support disabled mode. Set the Enabled property to false to disable a radio button. A user cannot focus or select this radio button.
The following code snippet disables radio buttons conditionally (based on installed languages).
<fieldset role="radiogroup">
<legend>Select your preferred language:</legend>
@foreach (var language in Languages) {
<DxRadio GroupName="disabled-option-radio-group"
@bind-GroupValue="@PreferredLanguage"
Value="@language"
Enabled="@IsLanguageInstalled(language)">
@GetOptionLabel(language)
</DxRadio>
}
</fieldset>
@code {
IEnumerable<string> Languages = new[] { "English", "简体中文", "Español", "Français", "Deutsch" };
bool IsLanguageInstalled(string language) => language != "Español";
string GetOptionLabel(string language) {
var result = language;
if (!IsLanguageInstalled(language))
result += " (not installed)";
return result;
}
}
Input Validation
You can add a standalone Radio component or Form Layout component to Blazor’s standard EditForm. This form validates user input based on data annotation attributes defined in a model and indicates errors.
For more information, refer to the following help topic: Validate Input.