syncfusion-blazor-chat-ui（同步融合 Blazor 聊天界面）

Syncfusion Blazor Chat UI

Build feature-rich conversational chat interfaces with the Syncfusion Blazor Chat UI component. This skill provides complete guidance for creating multi-user messaging applications, chat panels, and interactive conversation UIs in Blazor Server, WebAssembly, and Web App projects.

Component Overview

The SfChatUI component is a specialized UI control for building conversational chat applications. It manages the complete chat interface including:

• Message Management: Collections of chat messages with full message lifecycle
• User Management: Multi-user support with profiles, avatars, and status
• Presence Features: Typing indicators, online status, user identification
• Rich Rendering: Templates for messages, timestamps, typing indicators, suggestions
• File Support: File attachment upload and integration
• Event System: Lifecycle events and user interaction callbacks
• Customization: Complete styling and theming control

Navigation Guide

Getting Started

📄 Read: references/getting-started.md

• Installation and NuGet package setup
• Basic component structure and initialization
• User and message configuration
• Minimal working example with conversation

Messages & Users Management

📄 Read: references/messages-and-users.md

• ChatMessage configuration and properties
• UserModel setup and properties
• Message text content management
• Author identification and user assignment
• Building message collections and conversation history

User Profiles & Avatars

📄 Read: references/user-profiles-avatars.md

• Avatar URL configuration with images
• Avatar background color customization
• User status indicators (online, offline, busy, away)
• Custom CSS styling for users
• User identification and display names

Typing Indicators

📄 Read: references/typing-indicators.md

• TypingUsers property configuration
• Showing/hiding typing status indicators
• Managing multiple typing users
• Dynamic typing status updates
• Typing indicator template customization

Timestamps & Formatting

📄 Read: references/timestamps-and-formatting.md

• ShowTimestamp property to enable/disable timestamps
• Message timestamp configuration
• TimestampFormat customization
• TimeBreak separators (Today, Yesterday, specific dates)
• TimeBreak template styling

Templates & Customization

📄 Read: references/templates-and-customization.md

• EmptyChatTemplate for initial state display
• MessageTemplate for custom message rendering
• TimeBreakTemplate for date separators
• TypingUsersTemplate for typing display
• SuggestionTemplate for quick reply buttons
• CSS styling and theme integration

Attachments & Events

📄 Read: references/attachments-and-events.md

• File attachment configuration (Enable)
• SaveUrl and RemoveUrl endpoint setup
• AllowedFileTypes filtering
• MaxFileSize limits and constraints
• SaveFormat options (Blob vs Base64)
• Event handling: Created, MessageSend, UserTyping
• Attachment events: OnAttachmentUploadReady, UploadSuccess, UploadFailed

Programmatic API & Methods 🆕

📄 Read: references/programmatic-api.md

• ScrollToBottomAsync() for navigating to latest messages
• ScrollToMessageAsync() for jumping to specific messages
• UpdateMessageAsync() for editing existing messages
• FocusAsync() for input field control
• Complete examples with error handling

Advanced Features 🆕

📄 Read: references/advanced-features.md

• AutoScrollToBottom configuration
• EnableCompactMode for group chats
• Header and Footer customization
• Mention system (@mention) setup
• Quick reply suggestions
• LoadOnDemand for performance
• RTL (Right-to-Left) support
• Custom styling with CssClass

Quick Start

@using Syncfusion.Blazor.InteractiveChat

<div style="height: 500px; width: 600px;">
    <SfChatUI ID="chatUser" User="CurrentUser" Messages="Messages"></SfChatUI>
</div>

@code {
    private UserModel CurrentUser = new UserModel
    {
        ID = "user1",
        User = "Albert",
        AvatarBgColor = "#4a90e2"
    };

    private UserModel OtherUser = new UserModel
    {
        ID = "user2",
        User = "Michale Suyama",
        AvatarBgColor = "#7cb342"
    };

    private List<ChatMessage> Messages = new()
    {
        new ChatMessage
        {
            Text = "Hi, how are you?",
            Author = new UserModel { ID = "user1", User = "Albert" }
        },
        new ChatMessage
        {
            Text = "I'm doing great! How about you?",
            Author = new UserModel { ID = "user2", User = "Michale Suyama" }
        }
    };
}

Common Patterns

Pattern 1: Multi-User Conversation with Status

Display multiple users with online/offline status indicators:

<SfChatUI ID="chat" User="CurrentUser" Messages="Messages">
</SfChatUI>

@code {
    private UserModel CurrentUser = new UserModel
    {
        ID = "user1",
        User = "Albert",
        StatusIconCss = "e-icons e-user-online"
    };

    private List<ChatMessage> Messages = new();
}

Pattern 2: Chat with Typing Indicators

Show when users are typing:

<SfChatUI
    ID="chat"
    User="CurrentUser"
    Messages="Messages"
    TypingUsers="TypingUsers">
</SfChatUI>

@code {
    private List<UserModel> TypingUsers = new();

    private void UserStartTyping(UserModel user)
    {
        TypingUsers.Add(user);
        StateHasChanged();
    }
}

Pattern 3: Custom Message Templates

Personalize message appearance:

<SfChatUI ID="chat" User="CurrentUser" Messages="Messages">
    <MessageTemplate>
        <div class="custom-message">
            <strong>@context.Message.Author.User</strong>
            <p>@((MarkupString)context.Message.Text)</p>
        </div>
    </MessageTemplate>
</SfChatUI>

Pattern 4: Chat with File Attachments

Enable users to share files:

<SfChatUI ID="chat" User="CurrentUser" Messages="Messages">
    <ChatUIAttachment
        Enable
        SaveUrl="@SaveUrl"
        RemoveUrl="@RemoveUrl"
        AllowedFileTypes=".pdf,.docx,.jpg,.png">
    </ChatUIAttachment>
</SfChatUI>

@code {
    private string SaveUrl = "api/upload/save";
    private string RemoveUrl = "api/upload/remove";
}

Pattern 5: Auto-Scroll with Programmatic Control

Automatically scroll to bottom and navigate to specific messages:

<SfChatUI
    @ref="chatRef"
    ID="chat"
    User="CurrentUser"
    Messages="Messages"
    AutoScrollToBottom="true">
</SfChatUI>

<button @onclick="ScrollToBottom">Go to Latest</button>
<button @onclick="FocusInput">Focus Input</button>

@code {
    private SfChatUI chatRef;

    private async Task ScrollToBottom()
    {
        await chatRef.ScrollToBottomAsync();
    }

    private async Task FocusInput()
    {
        await chatRef.FocusAsync();
    }
}

Pattern 6: Message Editing with UpdateMessageAsync

Edit existing messages programmatically:

<SfChatUI @ref="chatRef" ID="chat" User="CurrentUser" Messages="Messages">
</SfChatUI>

@code {
    private SfChatUI chatRef;

    private async Task EditMessage(string messageId, string newText)
    {
        var message = Messages.FirstOrDefault(m => m.ID == messageId);
        if (message != null)
        {
            message.Text = newText;
            await chatRef.UpdateMessageAsync(message, messageId);
        }
    }
}

Pattern 7: Mention System for User Tagging

Enable users to mention others in messages:

<SfChatUI
    ID="chat"
    User="CurrentUser"
    Messages="Messages"
    MentionChar="@"
    MentionUsers="AllUsers"
    ValueSelecting="@OnMentionSelected">
</SfChatUI>

@code {
    private List<UserModel> AllUsers = new()
    {
        new UserModel { ID = "user1", User = "Albert" },
        new UserModel { ID = "user2", User = "Michale" },
        new UserModel { ID = "user3", User = "Reena" }
    };

    private void OnMentionSelected(MentionValueSelectingEventArgs<UserModel> args)
    {
        Console.WriteLine($"User mentioned: {args.ItemData.User}");
    }
}

Pattern 8: Compact Mode for Group Chats

Display all messages left-aligned for group chat style:

<SfChatUI
    ID="chat"
    User="CurrentUser"
    Messages="Messages"
    EnableCompactMode="true">
</SfChatUI>

@code {
    // In compact mode, all messages appear on left side
    // Useful for group chat or support ticket interfaces
}

Key Props

Programmatic Methods

The Chat UI component provides async methods for programmatic control:

ScrollToBottomAsync()

Scrolls the chat to the bottom, useful for showing latest messages:

@ref="chatRef"

private SfChatUI chatRef;

private async Task ShowLatestMessages()
{
    await chatRef.ScrollToBottomAsync();
}

ScrollToMessageAsync(string messageId)

Navigates to a specific message by ID:

private async Task NavigateToMessage(string targetMessageId)
{
    await chatRef.ScrollToMessageAsync(targetMessageId);
}

UpdateMessageAsync(ChatMessage message, string msgId)

Updates an existing message content:

private async Task EditMessage(string messageId, string newText)
{
    var message = Messages.FirstOrDefault(m => m.ID == messageId);
    if (message != null)
    {
        message.Text = newText;
        await chatRef.UpdateMessageAsync(message, messageId);
    }
}

FocusAsync()

Sets focus on the chat input field:

private async Task FocusChatInput()
{
    await chatRef.FocusAsync();
}

Common Use Cases

1. Customer Support Chat - Live support widget with agent presence
2. Team Messaging - Internal communication platform
3. Bot Integration - AI chatbot with user interface
4. Community Chat - Multi-user conversation rooms
5. Help Desk - Ticketing and messaging interface
6. Social Features - In-app messaging and notifications
7. Real-time Collaboration - Live chat during shared activities