Class RadzenChat

A chat interface component for displaying and sending messages in multi-participant conversations. RadzenChat provides a complete chat UI with message history, user avatars, typing indicators, and message composition. Creates a messaging interface similar to modern chat applications, ideal for customer support chats, team collaboration, messaging features, or AI chatbots. Features multi-user support displaying messages from multiple participants with avatars and names, chronological message list with sender identification, user avatars showing photos or initials with customizable colors, optional "User is typing..." feedback, text input with Send button for new messages, customizable templates for message rendering/empty state/typing indicator, automatic scrolling to newest messages, and message send time stamps. Provide a list of ChatUser objects for participants and ChatMessage objects for message history. Set CurrentUserId to distinguish the current user's messages (typically right-aligned) from others (left-aligned). Handle MessageSent to process new messages (save to database, send to server, etc.).

Inheritance

object

ComponentBase

RadzenComponent

RadzenChat

Implements

IComponent

IHandleEvent

IHandleAfterRender

IDisposable

Inherited Members

RadzenComponent.OnMouseEnter()

RadzenComponent.OnMouseLeave()

RadzenComponent.OnContextMenu(MouseEventArgs)

RadzenComponent.GetCssClass()

RadzenComponent.GetId()

RadzenComponent.Debounce(Func<Task>, int)

RadzenComponent.OnInitialized()

RadzenComponent.SetParametersAsync(ParameterView)

RadzenComponent.RaiseContextMenu(MouseEventArgs)

RadzenComponent.RaiseMouseEnter()

RadzenComponent.AddContextMenu()

RadzenComponent.RaiseMouseLeave()

RadzenComponent.Dispose()

RadzenComponent.Attributes

RadzenComponent.Element

RadzenComponent.MouseEnter

RadzenComponent.MouseLeave

RadzenComponent.ContextMenu

RadzenComponent.Culture

RadzenComponent.DefaultCulture

RadzenComponent.Style

RadzenComponent.Visible

RadzenComponent.UniqueID

RadzenComponent.JSRuntime

RadzenComponent.IsJSRuntimeAvailable

RadzenComponent.Reference

RadzenComponent.CurrentStyle

ComponentBase.OnInitializedAsync()

ComponentBase.OnParametersSet()

ComponentBase.OnParametersSetAsync()

ComponentBase.StateHasChanged()

ComponentBase.ShouldRender()

ComponentBase.OnAfterRender(bool)

ComponentBase.InvokeAsync(Action)

ComponentBase.InvokeAsync(Func<Task>)

ComponentBase.DispatchExceptionAsync(Exception)

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Namespace: Radzen.Blazor

Assembly: Radzen.Blazor.dll

Syntax

public class RadzenChat : RadzenComponent, IComponent, IHandleEvent, IHandleAfterRender, IDisposable

Examples

Basic chat:

<RadzenChat CurrentUserId=@currentUserId Users=@users Messages=@messages MessageSent=@OnMessageSent />
@code {
    string currentUserId = "user1";
    List<ChatUser> users = new() { new ChatUser { Id = "user1", Name = "John" }, new ChatUser { Id = "user2", Name = "Jane" } };
    List<ChatMessage> messages = new();

    async Task OnMessageSent(ChatMessage message)
    {
        messages.Add(message);
        await SaveMessage(message);
    }
}

Constructors

RadzenChat()

A chat interface component for displaying and sending messages in multi-participant conversations. RadzenChat provides a complete chat UI with message history, user avatars, typing indicators, and message composition. Creates a messaging interface similar to modern chat applications, ideal for customer support chats, team collaboration, messaging features, or AI chatbots. Features multi-user support displaying messages from multiple participants with avatars and names, chronological message list with sender identification, user avatars showing photos or initials with customizable colors, optional "User is typing..." feedback, text input with Send button for new messages, customizable templates for message rendering/empty state/typing indicator, automatic scrolling to newest messages, and message send time stamps. Provide a list of ChatUser objects for participants and ChatMessage objects for message history. Set CurrentUserId to distinguish the current user's messages (typically right-aligned) from others (left-aligned). Handle MessageSent to process new messages (save to database, send to server, etc.).

Declaration

public RadzenChat()

Examples

Basic chat:

<RadzenChat CurrentUserId=@currentUserId Users=@users Messages=@messages MessageSent=@OnMessageSent />
@code {
    string currentUserId = "user1";
    List<ChatUser> users = new() { new ChatUser { Id = "user1", Name = "John" }, new ChatUser { Id = "user2", Name = "Jane" } };
    List<ChatMessage> messages = new();

    async Task OnMessageSent(ChatMessage message)
    {
        messages.Add(message);
        await SaveMessage(message);
    }
}

Properties

ChatCleared

Event callback that is invoked when the chat is cleared.

Declaration

[Parameter]
public EventCallback ChatCleared { get; set; }

Property Value

Type	Description
EventCallback

CurrentUserId

Gets or sets the current user's participant ID.

Declaration

[Parameter]
public string CurrentUserId { get; set; }

Property Value

Type	Description
string

Disabled

Gets or sets whether the chat is disabled.

Declaration

[Parameter]
public bool Disabled { get; set; }

Property Value

Type	Description
bool

EmptyMessage

Gets or sets the message displayed when there are no messages.

Declaration

[Parameter]
public string EmptyMessage { get; set; }

Property Value

Type	Description
string

EmptyTemplate

Gets or sets the empty template shown when there are no messages.

Declaration

[Parameter]
public RenderFragment EmptyTemplate { get; set; }

Property Value

Type	Description
RenderFragment	The empty template.

InputAttributes

Specifies additional custom attributes that will be rendered by the input.

Declaration

[Parameter]
public IReadOnlyDictionary<string, object> InputAttributes { get; set; }

Property Value

Type	Description
IReadOnlyDictionary<string, object>	The attributes.

MaxMessages

Gets or sets the maximum number of messages to keep in the chat.

Declaration

[Parameter]
public int MaxMessages { get; set; }

Property Value

Type	Description
int

MaxVisibleUsers

Gets or sets the maximum number of users to show in the header.

Declaration

[Parameter]
public int MaxVisibleUsers { get; set; }

Property Value

Type	Description
int

MessageAdded

Event callback that is invoked when a new message is added.

Declaration

[Parameter]
public EventCallback<ChatMessage> MessageAdded { get; set; }

Property Value

Type	Description
EventCallback<ChatMessage>

MessageSent

Event callback that is invoked when a message is sent.

Declaration

[Parameter]
public EventCallback<ChatMessage> MessageSent { get; set; }

Property Value

Type	Description
EventCallback<ChatMessage>

MessageTemplate

Gets or sets the message template.

Declaration

[Parameter]
public RenderFragment<ChatMessage> MessageTemplate { get; set; }

Property Value

Type	Description
RenderFragment<ChatMessage>	The message template.

Messages

Gets or sets the list of chat messages.

Declaration

[Parameter]
public IEnumerable<ChatMessage> Messages { get; set; }

Property Value

Type	Description
IEnumerable<ChatMessage>

MessagesChanged

Event callback that is invoked when the messages list changes.

Declaration

[Parameter]
public EventCallback<IEnumerable<ChatMessage>> MessagesChanged { get; set; }

Property Value

Type	Description
EventCallback<IEnumerable<ChatMessage>>

Placeholder

Gets or sets the placeholder text for the input field.

Declaration

[Parameter]
public string Placeholder { get; set; }

Property Value

Type	Description
string

ReadOnly

Gets or sets whether the input is read-only.

Declaration

[Parameter]
public bool ReadOnly { get; set; }

Property Value

Type	Description
bool

ShowClearButton

Gets or sets whether to show the clear chat button.

Declaration

[Parameter]
public bool ShowClearButton { get; set; }

Property Value

Type	Description
bool

ShowUserNames

Gets or sets whether to show participant names above messages.

Declaration

[Parameter]
public bool ShowUserNames { get; set; }

Property Value

Type	Description
bool

ShowUsers

Gets or sets whether to show users in the header.

Declaration

[Parameter]
public bool ShowUsers { get; set; }

Property Value

Type	Description
bool

Title

Gets or sets the title displayed in the chat header.

Declaration

[Parameter]
public string Title { get; set; }

Property Value

Type	Description
string

UserAdded

Event callback that is invoked when a participant is added.

Declaration

[Parameter]
public EventCallback<ChatUser> UserAdded { get; set; }

Property Value

Type	Description
EventCallback<ChatUser>

UserRemoved

Event callback that is invoked when a participant is removed.

Declaration

[Parameter]
public EventCallback<ChatUser> UserRemoved { get; set; }

Property Value

Type	Description
EventCallback<ChatUser>

Users

Gets or sets the list of chat users.

Declaration

[Parameter]
public IEnumerable<ChatUser> Users { get; set; }

Property Value

Type	Description
IEnumerable<ChatUser>

UsersChanged

Event callback that is invoked when the users list changes.

Declaration

[Parameter]
public EventCallback<IEnumerable<ChatUser>> UsersChanged { get; set; }

Property Value

Type	Description
EventCallback<IEnumerable<ChatUser>>

Methods

AddMessage(string, string)

Adds a message to the chat.

Declaration

public Task<ChatMessage> AddMessage(string content, string userId)

Parameters

Type	Name	Description
string	content	The message content.
string	userId	The ID of the participant who sent the message.

Returns

Type	Description
Task<ChatMessage>	The created message.

AddUser(ChatUser)

Adds a participant to the chat.

Declaration

public Task AddUser(ChatUser participant)

Parameters

Type	Name	Description
ChatUser	participant	The participant to add.

Returns

Type	Description
Task

BuildRenderTree(RenderTreeBuilder)

A chat interface component for displaying and sending messages in multi-participant conversations. RadzenChat provides a complete chat UI with message history, user avatars, typing indicators, and message composition. Creates a messaging interface similar to modern chat applications, ideal for customer support chats, team collaboration, messaging features, or AI chatbots. Features multi-user support displaying messages from multiple participants with avatars and names, chronological message list with sender identification, user avatars showing photos or initials with customizable colors, optional "User is typing..." feedback, text input with Send button for new messages, customizable templates for message rendering/empty state/typing indicator, automatic scrolling to newest messages, and message send time stamps. Provide a list of ChatUser objects for participants and ChatMessage objects for message history. Set CurrentUserId to distinguish the current user's messages (typically right-aligned) from others (left-aligned). Handle MessageSent to process new messages (save to database, send to server, etc.).

Declaration

protected override void BuildRenderTree(RenderTreeBuilder __builder)

Parameters

Type	Name	Description
RenderTreeBuilder	__builder

Overrides

ComponentBase.BuildRenderTree(RenderTreeBuilder)

ClearChat()

Clears all messages from the chat.

Declaration

public Task ClearChat()

Returns

Type	Description
Task

GetComponentCssClass()

Gets the component CSS class.

Declaration

protected override string GetComponentCssClass()

Returns

Type	Description
string

Overrides

RadzenComponent.GetComponentCssClass()

GetMessages()

Gets the current list of messages.

Declaration

public IReadOnlyList<ChatMessage> GetMessages()

Returns

Type	Description
IReadOnlyList<ChatMessage>

GetUser(string)

Gets a participant by their ID.

Declaration

public ChatUser GetUser(string userId)

Parameters

Type	Name	Description
string	userId	The participant ID.

Returns

Type	Description
ChatUser	The participant or null if not found.

GetUsers()

Gets the current list of users.

Declaration

public IReadOnlyList<ChatUser> GetUsers()

Returns

Type	Description
IReadOnlyList<ChatUser>

LoadMessages(IEnumerable<ChatMessage>)

Loads messages from an external source.

Declaration

public Task LoadMessages(IEnumerable<ChatMessage> messages)

Parameters

Type	Name	Description
IEnumerable<ChatMessage>	messages	The messages to load.

Returns

Type	Description
Task

OnAfterRenderAsync(bool)

Called by the Blazor runtime.

Declaration

protected override Task OnAfterRenderAsync(bool firstRender)

Parameters

Type	Name	Description
bool	firstRender

Returns

Type	Description
Task

Overrides

RadzenComponent.OnAfterRenderAsync(bool)

RemoveUser(string)

Removes a participant from the chat.

Declaration

public Task RemoveUser(string userId)

Parameters

Type	Name	Description
string	userId	The ID of the participant to remove.

Returns

Type	Description
Task

SendMessage(string, string)

Sends a message programmatically.

Declaration

public Task SendMessage(string content, string userId = null)

Parameters

Type	Name	Description
string	content	The message content to send.
string	userId	The ID of the participant sending the message (defaults to CurrentUserId).

Returns

Type	Description
Task

UpdateUserStatus(string, bool)

Updates a participant's online status.

Declaration

public Task UpdateUserStatus(string userId, bool isOnline)

Parameters

Type	Name	Description
string	userId	The participant ID.
bool	isOnline	The online status.

Returns

Type	Description
Task

Implements

IComponent

IHandleEvent

IHandleAfterRender

IDisposable