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📚 Table of Contents
Introduction to Blazor Superpowers
Blazor Architecture Deep Dive
Component-Based Development
Real-Time Features with SignalR
Blazor Server vs WebAssembly
Advanced Component Patterns
State Management Strategies
Performance Optimization
Real-World Application
Best Practices & Deployment
1. Introduction to Blazor Superpowers
1.1 What is Blazor?
Blazor is a revolutionary framework that enables building interactive web UIs using C# instead of JavaScript. It represents a paradigm shift in web development for .NET developers.
// Traditional JavaScript approach
document.getElementById('message').innerHTML = 'Hello World';
// Blazor C# approach
<h1>@message</h1>
@code {
private string message = "Hello World";
}
1.2 Why Blazor Matters
Real-Life Scenario: Imagine building a financial dashboard that updates stock prices in real-time without page refreshes, using only C# skills your team already possesses.
// Real-time stock ticker component
<div class="stock-ticker">
@foreach (var stock in stocks)
{
<div class="stock-item @(stock.IsRising ? "rising" : "falling")">
<span>@stock.Symbol</span>
<span>@stock.Price.ToString("C")</span>
<span>@stock.ChangePercentage.ToString("P")</span>
</div>
}
</div>
1.3 Blazor Hosting Models
1.3.1 Blazor Server
// Program.cs for Blazor Server
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddSingleton<WeatherForecastService>();
var app = builder.Build();
app.UseStaticFiles();
app.UseRouting();
app.MapBlazorHub();
app.MapFallbackToPage("/_Host");
app.Run();
1.3.2 Blazor WebAssembly
// Program.cs for Blazor WebAssembly
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddHttpClient();
var app = builder.Build();
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.MapBlazorHub();
app.MapFallbackToPage("/_Host");
app.Run();
2. Blazor Architecture Deep Dive
2.1 Component Lifecycle
Understanding the component lifecycle is crucial for building robust applications:
public class LifecycleDemo : ComponentBase
{
// 1. SetParametersAsync - First lifecycle method
public override async Task SetParametersAsync(ParameterView parameters)
{
Console.WriteLine("SetParametersAsync - Setting component parameters");
await base.SetParametersAsync(parameters);
}
// 2. OnInitialized / OnInitializedAsync
protected override void OnInitialized()
{
Console.WriteLine("OnInitialized - Component initialized");
base.OnInitialized();
}
protected override async Task OnInitializedAsync()
{
Console.WriteLine("OnInitializedAsync - Async initialization");
await LoadDataAsync();
}
// 3. OnParametersSet / OnParametersSetAsync
protected override void OnParametersSet()
{
Console.WriteLine("OnParametersSet - Parameters set");
base.OnParametersSet();
}
// 4. OnAfterRender / OnAfterRenderAsync
protected override void OnAfterRender(bool firstRender)
{
if (firstRender)
{
Console.WriteLine("OnAfterRender - First render complete");
// Initialize JavaScript interop here
}
base.OnAfterRender(firstRender);
}
// 5. ShouldRender - Control re-rendering
protected override bool ShouldRender()
{
Console.WriteLine("ShouldRender - Deciding whether to render");
return base.ShouldRender();
}
private async Task LoadDataAsync()
{
// Simulate data loading
await Task.Delay(1000);
}
// Dispose pattern for cleanup
public void Dispose()
{
Console.WriteLine("Dispose - Cleaning up resources");
}
}
2.2 Rendering Process
Blazor uses a sophisticated rendering process:
// Custom component demonstrating rendering
<div class="render-demo">
<h3>Render Counter: @renderCount</h3>
<button @onclick="IncrementCount" class="btn btn-primary">
Trigger Render
</button>
@if (showAdditionalContent)
{
<div class="additional-content">
<p>This content conditionally renders</p>
<ChildComponent Message="Hello from parent" />
</div>
}
</div>
@code {
private int renderCount = 0;
private bool showAdditionalContent = false;
private int currentCount = 0;
protected override void OnAfterRender(bool firstRender)
{
renderCount++;
StateHasChanged(); // This would cause infinite loop - don't do this!
}
private void IncrementCount()
{
currentCount++;
showAdditionalContent = currentCount % 2 == 0;
// StateHasChanged() is automatically called for event handlers
}
}
// Child component
<div class="child-component">
<p>@Message - Rendered: @DateTime.Now.ToString("HH:mm:ss.fff")</p>
</div>
@code {
[Parameter]
public string Message { get; set; } = string.Empty;
}
2.3 Event Handling System
Blazor provides a comprehensive event handling system:
@page "/event-demo"
<div class="event-demo-container">
<h3>Event Handling Examples</h3>
<!-- Mouse Events -->
<div class="mouse-events">
<div class="interactive-box"
@onmouseover="HandleMouseOver"
@onmouseout="HandleMouseOut"
@onclick="HandleClick"
@oncontextmenu="HandleContextMenu"
style="width: 200px; height: 100px; background-color: @boxColor; display: flex; align-items: center; justify-content: center;">
Interact with me!
</div>
<p>Event Status: @eventStatus</p>
</div>
<!-- Keyboard Events -->
<div class="keyboard-events">
<input @onkeydown="HandleKeyDown"
@onkeyup="HandleKeyUp"
@oninput="HandleInput"
placeholder="Type something..."
class="form-control" />
<p>Last Key: @lastKey | Input Value: @inputValue</p>
</div>
<!-- Form Events -->
<div class="form-events">
<select @onchange="HandleSelectChange" class="form-select">
<option value="">Choose an option</option>
<option value="1">Option 1</option>
<option value="2">Option 2</option>
<option value="3">Option 3</option>
</select>
<p>Selected: @selectedValue</p>
<input type="checkbox" @onchange="HandleCheckboxChange" />
<span>Checkbox is @(isChecked ? "checked" : "unchecked")</span>
</div>
<!-- Custom Event Arguments -->
<div class="custom-events">
<button @onclick:stopPropagation="HandleButtonClick"
class="btn btn-info">
Click (No Propagation)
</button>
<button @onclick="async () => await HandleAsyncClick()"
class="btn btn-warning">
Async Click
</button>
</div>
</div>
@code {
private string eventStatus = "No events yet";
private string boxColor = "lightblue";
private string lastKey = "None";
private string inputValue = "";
private string selectedValue = "";
private bool isChecked = false;
private void HandleMouseOver()
{
eventStatus = "Mouse Over";
boxColor = "lightgreen";
}
private void HandleMouseOut()
{
eventStatus = "Mouse Out";
boxColor = "lightblue";
}
private void HandleClick(MouseEventArgs e)
{
eventStatus = $"Clicked at ({e.ClientX}, {e.ClientY})";
}
private void HandleContextMenu(MouseEventArgs e)
{
eventStatus = "Context Menu prevented";
// Prevent default context menu
}
private void HandleKeyDown(KeyboardEventArgs e)
{
lastKey = $"KeyDown: {e.Key} (Code: {e.Code})";
}
private void HandleKeyUp(KeyboardEventArgs e)
{
lastKey = $"KeyUp: {e.Key}";
}
private void HandleInput(ChangeEventArgs e)
{
inputValue = e.Value?.ToString() ?? "";
}
private void HandleSelectChange(ChangeEventArgs e)
{
selectedValue = e.Value?.ToString() ?? "None";
}
private void HandleCheckboxChange(ChangeEventArgs e)
{
isChecked = (bool)(e.Value ?? false);
}
private void HandleButtonClick()
{
eventStatus = "Button clicked (propagation stopped)";
}
private async Task HandleAsyncClick()
{
eventStatus = "Async operation starting...";
StateHasChanged(); // Force immediate UI update
await Task.Delay(1000); // Simulate async work
eventStatus = "Async operation completed!";
}
}
3. Component-Based Development
3.1 Component Fundamentals
Components are the building blocks of Blazor applications:
// ProductCard.razor
<div class="product-card">
<div class="product-image">
<img src="@Product.ImageUrl" alt="@Product.Name" />
@if (Product.IsOnSale)
{
<span class="sale-badge">SALE</span>
}
</div>
<div class="product-info">
<h3>@Product.Name</h3>
<p class="description">@Product.Description</p>
<div class="pricing">
@if (Product.IsOnSale)
{
<span class="original-price">@Product.Price.ToString("C")</span>
<span class="sale-price">@Product.SalePrice.ToString("C")</span>
}
else
{
<span class="price">@Product.Price.ToString("C")</span>
}
</div>
<div class="rating">
@for (int i = 1; i <= 5; i++)
{
<span class="star @(i <= Product.Rating ? "filled" : "")">★</span>
}
<span class="rating-count">(@Product.ReviewCount)</span>
</div>
<div class="actions">
<button class="btn btn-primary" @onclick="AddToCart">
Add to Cart
</button>
<button class="btn btn-outline-secondary" @onclick="ToggleFavorite">
@(IsFavorite ? "❤️" : "🤍")
</button>
</div>
</div>
</div>
@code {
[Parameter]
public Product Product { get; set; } = new();
[Parameter]
public EventCallback<Product> OnAddToCart { get; set; }
[Parameter]
public EventCallback<Product> OnToggleFavorite { get; set; }
private bool IsFavorite { get; set; }
private async Task AddToCart()
{
if (OnAddToCart.HasDelegate)
{
await OnAddToCart.InvokeAsync(Product);
}
}
private async Task ToggleFavorite()
{
IsFavorite = !IsFavorite;
if (OnToggleFavorite.HasDelegate)
{
await OnToggleFavorite.InvokeAsync(Product);
}
}
}
// Supporting classes
public class Product
{
public int Id { get; set; }
public string Name { get; set; } = string.Empty;
public string Description { get; set; } = string.Empty;
public decimal Price { get; set; }
public decimal SalePrice { get; set; }
public bool IsOnSale { get; set; }
public string ImageUrl { get; set; } = string.Empty;
public int Rating { get; set; }
public int ReviewCount { get; set; }
public string Category { get; set; } = string.Empty;
}
3.2 Advanced Component Patterns
3.2.1 Render Fragments
// CardComponent.razor
<div class="card @AdditionalCss">
@if (HeaderContent != null)
{
<div class="card-header">
@HeaderContent
</div>
}
<div class="card-body">
@if (BodyContent != null)
{
@BodyContent
}
else
{
<p>Default body content</p>
}
</div>
@if (FooterContent != null)
{
<div class="card-footer">
@FooterContent
</div>
}
</div>
@code {
[Parameter]
public string AdditionalCss { get; set; } = string.Empty;
[Parameter]
public RenderFragment? HeaderContent { get; set; }
[Parameter]
public RenderFragment? BodyContent { get; set; }
[Parameter]
public RenderFragment? FooterContent { get; set; }
}
// Usage in parent component
<CardComponent AdditionalCss="shadow-lg">
<HeaderContent>
<h4>Custom Header</h4>
<small>With additional information</small>
</HeaderContent>
<BodyContent>
<p>This is custom body content</p>
<button class="btn btn-primary">Action</button>
</BodyContent>
<FooterContent>
<div class="text-muted">Custom footer content</div>
</FooterContent>
</CardComponent>
3.2.2 Cascading Parameters
// ThemeProvider.razor
<CascadingValue Value="CurrentTheme" IsFixed="false">
@ChildContent
</CascadingValue>
@code {
[Parameter]
public RenderFragment ChildContent { get; set; } = default!;
private Theme currentTheme = new();
public Theme CurrentTheme
{
get => currentTheme;
set
{
currentTheme = value;
StateHasChanged();
}
}
public void SetTheme(Action<Theme> themeAction)
{
themeAction(currentTheme);
StateHasChanged();
}
}
// ThemedButton.razor
<button class="btn"
style="background-color: @Theme.PrimaryColor; color: @Theme.TextColor;"
@onclick="OnClick"
@attributes="AdditionalAttributes">
@ChildContent
</button>
@code {
[CascadingParameter]
protected Theme Theme { get; set; } = new();
[Parameter]
public RenderFragment? ChildContent { get; set; }
[Parameter]
public EventCallback OnClick { get; set; }
[Parameter(CaptureUnmatchedValues = true)]
public Dictionary<string, object> AdditionalAttributes { get; set; } = new();
}
// Theme class
public class Theme
{
public string PrimaryColor { get; set; } = "#007bff";
public string SecondaryColor { get; set; } = "#6c757d";
public string TextColor { get; set; } = "#ffffff";
public string BackgroundColor { get; set; } = "#ffffff";
public string BorderRadius { get; set; } = "4px";
}
3.3 Component Communication
3.3.1 Parent-Child Communication
// ParentComponent.razor
@page "/parent-demo"
<div class="parent-container">
<h3>Parent-Child Communication Demo</h3>
<div class="controls">
<button @onclick="AddNewItem" class="btn btn-success">
Add New Item
</button>
<button @onclick="ClearAll" class="btn btn-danger">
Clear All
</button>
</div>
<ChildComponent
Items="itemList"
OnItemSelected="HandleItemSelected"
OnItemDeleted="HandleItemDeleted"
OnItemsChanged="HandleItemsChanged" />
<div class="status">
<p>Selected Item: @selectedItem</p>
<p>Total Items: @itemList.Count</p>
<p>Last Action: @lastAction</p>
</div>
</div>
@code {
private List<string> itemList = new() { "Item 1", "Item 2", "Item 3" };
private string selectedItem = "None";
private string lastAction = "None";
private void AddNewItem()
{
itemList.Add($"Item {itemList.Count + 1}");
lastAction = $"Added item at {DateTime.Now:HH:mm:ss}";
}
private void ClearAll()
{
itemList.Clear();
selectedItem = "None";
lastAction = $"Cleared all items at {DateTime.Now:HH:mm:ss}";
}
private void HandleItemSelected(string item)
{
selectedItem = item;
lastAction = $"Selected: {item} at {DateTime.Now:HH:mm:ss}";
}
private void HandleItemDeleted(string item)
{
itemList.Remove(item);
lastAction = $"Deleted: {item} at {DateTime.Now:HH:mm:ss}";
}
private void HandleItemsChanged(List<string> items)
{
// This demonstrates two-way binding pattern
itemList = items;
lastAction = $"Items changed at {DateTime.Now:HH:mm:ss}";
}
}
// ChildComponent.razor
<div class="child-container">
<h4>Child Component</h4>
<ul class="item-list">
@foreach (var item in Items)
{
<li class="item">
<span @onclick="() => SelectItem(item)"
class="item-text @(selectedItem == item ? "selected" : "")">
@item
</span>
<button @onclick="() => DeleteItem(item)"
class="btn btn-sm btn-outline-danger">
Delete
</button>
</li>
}
</ul>
@if (Items.Count == 0)
{
<p class="text-muted">No items available</p>
}
<div class="child-controls">
<button @onclick="ReverseItems" class="btn btn-warning">
Reverse Items
</button>
</div>
</div>
@code {
[Parameter]
public List<string> Items { get; set; } = new();
[Parameter]
public EventCallback<string> OnItemSelected { get; set; }
[Parameter]
public EventCallback<string> OnItemDeleted { get; set; }
[Parameter]
public EventCallback<List<string>> OnItemsChanged { get; set; }
private string selectedItem = string.Empty;
private async Task SelectItem(string item)
{
selectedItem = item;
if (OnItemSelected.HasDelegate)
{
await OnItemSelected.InvokeAsync(item);
}
}
private async Task DeleteItem(string item)
{
if (OnItemDeleted.HasDelegate)
{
await OnItemDeleted.InvokeAsync(item);
}
}
private async Task ReverseItems()
{
Items.Reverse();
if (OnItemsChanged.HasDelegate)
{
await OnItemsChanged.InvokeAsync(Items);
}
}
}
4. Real-Time Features with SignalR
4.1 SignalR Integration
Real-time communication is a Blazor superpower:
// ChatHub.cs - SignalR Hub
using Microsoft.AspNetCore.SignalR;
public class ChatHub : Hub
{
private static readonly Dictionary<string, string> userConnections = new();
private static readonly List<ChatMessage> messageHistory = new();
public async Task SendMessage(string user, string message)
{
var chatMessage = new ChatMessage
{
User = user,
Message = message,
Timestamp = DateTime.Now
};
messageHistory.Add(chatMessage);
// Keep only last 100 messages
if (messageHistory.Count > 100)
{
messageHistory.RemoveAt(0);
}
await Clients.All.SendAsync("ReceiveMessage", chatMessage);
}
public async Task JoinChat(string userName)
{
userConnections[Context.ConnectionId] = userName;
await Clients.All.SendAsync("UserJoined", userName);
// Send message history to new user
await Clients.Caller.SendAsync("LoadMessageHistory", messageHistory);
}
public async Task LeaveChat()
{
if (userConnections.TryGetValue(Context.ConnectionId, out var userName))
{
userConnections.Remove(Context.ConnectionId);
await Clients.All.SendAsync("UserLeft", userName);
}
}
public override async Task OnDisconnectedAsync(Exception? exception)
{
await LeaveChat();
await base.OnDisconnectedAsync(exception);
}
}
public class ChatMessage
{
public string User { get; set; } = string.Empty;
public string Message { get; set; } = string.Empty;
public DateTime Timestamp { get; set; }
}
4.2 Real-Time Chat Component
// RealTimeChat.razor
@page "/chat"
@using Microsoft.AspNetCore.SignalR.Client
@implements IAsyncDisposable
<div class="chat-container">
<div class="chat-header">
<h3>Real-Time Chat</h3>
<div class="connection-status">
<span class="status-indicator @(isConnected ? "connected" : "disconnected")"></span>
@connectionStatus
</div>
</div>
<div class="user-setup" style="display: @(string.IsNullOrEmpty(currentUser) ? "block" : "none")">
<div class="form-group">
<label>Enter your name:</label>
<input @bind="userNameInput" @onkeypress="HandleUserNameKeyPress"
class="form-control" maxlength="20" />
<button @onclick="SetUserName" class="btn btn-primary mt-2">Join Chat</button>
</div>
</div>
<div class="chat-room" style="display: @(string.IsNullOrEmpty(currentUser) ? "none" : "block")">
<div class="messages-container" ref="messagesContainer">
@foreach (var message in messages)
{
<div class="message @(message.User == currentUser ? "own-message" : "")">
<div class="message-header">
<strong>@message.User</strong>
<small>@message.Timestamp.ToString("HH:mm")</small>
</div>
<div class="message-content">@message.Message</div>
</div>
}
@if (!isConnected)
{
<div class="alert alert-warning">Reconnecting...</div>
}
</div>
<div class="message-input">
<div class="input-group">
<input @bind="newMessage" @onkeypress="HandleMessageKeyPress"
placeholder="Type your message..." class="form-control"
disabled="@(!isConnected)" />
<button @onclick="SendMessage" class="btn btn-success"
disabled="@(!isConnected || string.IsNullOrWhiteSpace(newMessage))">
Send
</button>
</div>
</div>
<div class="chat-info">
<button @onclick="LeaveChat" class="btn btn-outline-secondary btn-sm">
Leave Chat
</button>
<span class="user-count">Users online: @onlineUsers.Count</span>
</div>
</div>
</div>
@code {
private HubConnection? hubConnection;
private List<ChatMessage> messages = new();
private List<string> onlineUsers = new();
private string? currentUser;
private string userNameInput = string.Empty;
private string newMessage = string.Empty;
private string connectionStatus = "Disconnected";
private bool isConnected = false;
private ElementReference messagesContainer;
protected override async Task OnInitializedAsync()
{
await InitializeSignalR();
}
private async Task InitializeSignalR()
{
hubConnection = new HubConnectionBuilder()
.WithUrl(NavigationManager.BaseUri + "chathub")
.WithAutomaticReconnect(new[] { TimeSpan.Zero, TimeSpan.FromSeconds(2),
TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(10) })
.Build();
hubConnection.Reconnecting += ex =>
{
connectionStatus = "Reconnecting...";
isConnected = false;
StateHasChanged();
return Task.CompletedTask;
};
hubConnection.Reconnected += connectionId =>
{
connectionStatus = "Connected";
isConnected = true;
StateHasChanged();
return Task.CompletedTask;
};
hubConnection.Closed += async ex =>
{
connectionStatus = "Disconnected";
isConnected = false;
StateHasChanged();
// Try to reconnect after 5 seconds
await Task.Delay(5000);
await hubConnection.StartAsync();
};
// Setup message handlers
hubConnection.On<ChatMessage>("ReceiveMessage", (message) =>
{
messages.Add(message);
StateHasChanged();
ScrollToBottom();
});
hubConnection.On<string>("UserJoined", (userName) =>
{
onlineUsers.Add(userName);
messages.Add(new ChatMessage
{
User = "System",
Message = $"{userName} joined the chat",
Timestamp = DateTime.Now
});
StateHasChanged();
ScrollToBottom();
});
hubConnection.On<string>("UserLeft", (userName) =>
{
onlineUsers.Remove(userName);
messages.Add(new ChatMessage
{
User = "System",
Message = $"{userName} left the chat",
Timestamp = DateTime.Now
});
StateHasChanged();
ScrollToBottom();
});
hubConnection.On<List<ChatMessage>>("LoadMessageHistory", (history) =>
{
messages = history;
StateHasChanged();
ScrollToBottom();
});
await hubConnection.StartAsync();
connectionStatus = "Connected";
isConnected = true;
StateHasChanged();
}
private async Task SetUserName()
{
if (!string.IsNullOrWhiteSpace(userNameInput))
{
currentUser = userNameInput.Trim();
await hubConnection!.InvokeAsync("JoinChat", currentUser);
StateHasChanged();
}
}
private async Task SendMessage()
{
if (!string.IsNullOrWhiteSpace(newMessage) && hubConnection != null)
{
await hubConnection.InvokeAsync("SendMessage", currentUser, newMessage);
newMessage = string.Empty;
StateHasChanged();
}
}
private async Task LeaveChat()
{
if (hubConnection != null)
{
await hubConnection.InvokeAsync("LeaveChat");
currentUser = null;
messages.Clear();
onlineUsers.Clear();
StateHasChanged();
}
}
private void HandleMessageKeyPress(KeyboardEventArgs e)
{
if (e.Key == "Enter")
{
SendMessage();
}
}
private void HandleUserNameKeyPress(KeyboardEventArgs e)
{
if (e.Key == "Enter")
{
SetUserName();
}
}
private async void ScrollToBottom()
{
try
{
await JSRuntime.InvokeVoidAsync("scrollToBottom", messagesContainer);
}
catch (Exception ex)
{
Console.WriteLine($"Error scrolling: {ex.Message}");
}
}
public async ValueTask DisposeAsync()
{
if (hubConnection != null)
{
await hubConnection.DisposeAsync();
}
}
[Inject]
private NavigationManager NavigationManager { get; set; } = default!;
[Inject]
private IJSRuntime JSRuntime { get; set; } = default!;
}
4.3 JavaScript Interop for Enhanced Functionality
javascript
// wwwroot/js/chatInterop.js
function scrollToBottom(element) {
element.scrollTop = element.scrollHeight;
}
function focusElement(element) {
element.focus();
}
function getElementScrollHeight(element) {
return element.scrollHeight;
}
function playNotificationSound() {
const audio = new Audio('/sounds/notification.mp3');
audio.play().catch(e => console.log('Audio play failed:', e));
}
// Enhanced chat component with JavaScript interop
@inject IJSRuntime JSRuntime
@code {
private async Task ScrollToBottom()
{
try
{
await JSRuntime.InvokeVoidAsync("scrollToBottom", messagesContainer);
}
catch (Exception ex)
{
Console.WriteLine($"Scroll error: {ex.Message}");
}
}
private async Task PlayNotificationSound()
{
try
{
await JSRuntime.InvokeVoidAsync("playNotificationSound");
}
catch (Exception ex)
{
Console.WriteLine($"Audio error: {ex.Message}");
}
}
}
5. Blazor Server vs WebAssembly
5.1 Performance Comparison
// PerformanceDemo.razor
@page "/performance-demo"
<div class="performance-container">
<h3>Blazor Server vs WebAssembly Performance</h3>
<div class="hosting-info">
<div class="info-card server">
<h4>🚀 Blazor Server</h4>
<ul>
<li><strong>Latency:</strong> @serverLatency ms</li>
<li><strong>Memory Usage:</strong> @serverMemory MB</li>
<li><strong>Connection State:</strong> @serverConnectionState</li>
</ul>
</div>
<div class="info-card wasm">
<h4>⚡ Blazor WebAssembly</h4>
<ul>
<li><strong>Latency:</strong> @wasmLantency ms</li>
<li><strong>Memory Usage:</strong> @wasmMemory MB</li>
<li><strong>Download Size:</strong> @downloadSize MB</li>
</ul>
</div>
</div>
<div class="performance-tests">
<h4>Performance Tests</h4>
<div class="test-section">
<h5>Rendering Performance</h5>
<button @onclick="RunRenderTest" class="btn btn-primary"
disabled="@isRunningTest">
@(isRunningTest ? "Running..." : "Run Render Test")
</button>
<p>Render Time: @renderTime ms for @itemCount items</p>
<div class="items-grid">
@foreach (var item in displayItems)
{
<div class="item-card">Item @item</div>
}
</div>
</div>
<div class="test-section">
<h5>JavaScript Interop Performance</h5>
<button @onclick="RunJsInteropTest" class="btn btn-secondary"
disabled="@isRunningTest">
Run JS Interop Test
</button>
<p>JS Interop Time: @jsInteropTime ms</p>
</div>
<div class="test-section">
<h5>CPU Intensive Operation</h5>
<button @onclick="RunCpuTest" class="btn btn-warning"
disabled="@isRunningTest">
Run CPU Test
</button>
<p>CPU Operation Time: @cpuTime ms</p>
</div>
</div>
<div class="recommendations">
<h4>Hosting Recommendations</h4>
<div class="recommendation @(currentRecommendation == "Server" ? "active" : "")">
<strong>Blazor Server Recommended When:</strong>
<ul>
<li>Fast initial load time is critical</li>
<li>Client devices have limited resources</li>
<li>Application requires real-time updates</li>
<li>Strong server-side security needed</li>
</ul>
</div>
<div class="recommendation @(currentRecommendation == "Wasm" ? "active" : "")">
<strong>Blazor WebAssembly Recommended When:</strong>
<ul>
<li>Offline functionality required</li>
<li>Reduced server load is important</li>
<li>Client-side processing needed</li>
<li>Progressive Web App (PWA) features</li>
</ul>
</div>
</div>
</div>
@code {
private string serverLatency = "Calculating...";
private string wasmLantency = "Calculating...";
private string serverMemory = "0";
private string wasmMemory = "0";
private string downloadSize = "0";
private string serverConnectionState = "Unknown";
private string renderTime = "0";
private string jsInteropTime = "0";
private string cpuTime = "0";
private bool isRunningTest = false;
private int itemCount = 100;
private List<int> displayItems = new();
private string currentRecommendation = "Server";
protected override async Task OnInitializedAsync()
{
await CalculatePerformanceMetrics();
await UpdateConnectionState();
}
private async Task CalculatePerformanceMetrics()
{
// Simulate performance metrics calculation
serverLatency = "15-50";
wasmLantency = "5-20";
serverMemory = "512";
wasmMemory = "256";
downloadSize = "10-15";
StateHasChanged();
}
private async Task UpdateConnectionState()
{
// This would typically check actual connection state
serverConnectionState = "Healthy";
StateHasChanged();
}
private async Task RunRenderTest()
{
isRunningTest = true;
StateHasChanged();
var stopwatch = System.Diagnostics.Stopwatch.StartNew();
displayItems.Clear();
for (int i = 0; i < itemCount; i++)
{
displayItems.Add(i);
}
stopwatch.Stop();
renderTime = stopwatch.ElapsedMilliseconds.ToString();
isRunningTest = false;
StateHasChanged();
}
private async Task RunJsInteropTest()
{
isRunningTest = true;
StateHasChanged();
var stopwatch = System.Diagnostics.Stopwatch.StartNew();
// Simulate multiple JS interop calls
for (int i = 0; i < 100; i++)
{
await JSRuntime.InvokeVoidAsync("console.log", $"Test {i}");
}
stopwatch.Stop();
jsInteropTime = stopwatch.ElapsedMilliseconds.ToString();
isRunningTest = false;
StateHasChanged();
}
private async Task RunCpuTest()
{
isRunningTest = true;
StateHasChanged();
var stopwatch = System.Diagnostics.Stopwatch.StartNew();
// Simulate CPU-intensive work
await Task.Run(() =>
{
var result = 0;
for (int i = 0; i < 1000000; i++)
{
result += i * i;
}
});
stopwatch.Stop();
cpuTime = stopwatch.ElapsedMilliseconds.ToString();
isRunningTest = false;
StateHasChanged();
}
[Inject]
private IJSRuntime JSRuntime { get; set; } = default!;
}
5.2 Hybrid Approach
// Program.cs for hybrid approach
var builder = WebApplication.CreateBuilder(args);
// Configure both Server and WASM
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
// Add HttpClient for WASM
builder.Services.AddHttpClient();
// Add shared services
builder.Services.AddSingleton<WeatherForecastService>();
builder.Services.AddScoped<IDataService, DataService>();
var app = builder.Build();
if (app.Environment.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
// Map Blazor Server
app.MapBlazorHub();
app.MapFallbackToPage("/_Host");
// Map Blazor WASM (if needed)
app.MapFallbackToFile("index.html");
app.Run();
6. Advanced Component Patterns
6.1 Generic Components
// GenericTable.razor
@typeparam TItem
<div class="generic-table">
<div class="table-header">
<h4>@Title</h4>
@if (ShowSearch)
{
<div class="search-box">
<input @bind="searchText" @oninput="OnSearch"
placeholder="Search..." class="form-control" />
</div>
}
</div>
<div class="table-responsive">
<table class="table table-striped table-hover">
<thead>
<tr>
@foreach (var column in Columns)
{
<th @onclick="() => SortBy(column.Field)"
style="cursor: pointer; min-width: @column.Width">
@column.Title
@if (sortField == column.Field)
{
<span>@(sortAscending ? "↑" : "↓")</span>
}
</th>
}
@if (Actions != null)
{
<th>Actions</th>
}
</tr>
</thead>
<tbody>
@foreach (var item in FilteredItems)
{
<tr>
@foreach (var column in Columns)
{
<td>
@if (column.Template != null)
{
@column.Template(item)
}
else
{
@GetPropertyValue(item, column.Field)
}
</td>
}
@if (Actions != null)
{
<td>
@Actions(item)
</td>
}
</tr>
}
</tbody>
</table>
</div>
@if (PaginationEnabled)
{
<div class="table-footer">
<div class="pagination-controls">
<button @onclick="FirstPage" disabled="@(currentPage == 1)"
class="btn btn-sm btn-outline-primary">First</button>
<button @onclick="PreviousPage" disabled="@(currentPage == 1)"
class="btn btn-sm btn-outline-primary">Previous</button>
<span class="page-info">
Page @currentPage of @totalPages
</span>
<button @onclick="NextPage" disabled="@(currentPage == totalPages)"
class="btn btn-sm btn-outline-primary">Next</button>
<button @onclick="LastPage" disabled="@(currentPage == totalPages)"
class="btn btn-sm btn-outline-primary">Last</button>
</div>
<div class="page-size">
<select @bind="pageSize" @onchange="OnPageSizeChanged"
class="form-select form-select-sm">
<option value="5">5 per page</option>
<option value="10">10 per page</option>
<option value="20">20 per page</option>
<option value="50">50 per page</option>
</select>
</div>
</div>
}
@if (!FilteredItems.Any())
{
<div class="no-data">
<p>No data available</p>
</div>
}
</div>
@code {
[Parameter]
public string Title { get; set; } = "Data Table";
[Parameter]
public IReadOnlyList<TItem> Items { get; set; } = new List<TItem>();
[Parameter]
public IReadOnlyList<TableColumn<TItem>> Columns { get; set; } = new List<TableColumn<TItem>>();
[Parameter]
public RenderFragment<TItem>? Actions { get; set; }
[Parameter]
public bool ShowSearch { get; set; } = true;
[Parameter]
public bool PaginationEnabled { get; set; } = true;
[Parameter]
public int DefaultPageSize { get; set; } = 10;
private IEnumerable<TItem> FilteredItems => filteredItems.Skip((currentPage - 1) * pageSize).Take(pageSize);
private List<TItem> filteredItems = new();
private string searchText = string.Empty;
private string sortField = string.Empty;
private bool sortAscending = true;
private int currentPage = 1;
private int pageSize = 10;
private int totalPages => (int)Math.Ceiling((double)filteredItems.Count / pageSize);
protected override void OnParametersSet()
{
base.OnParametersSet();
ApplyFilteringAndSorting();
}
private void ApplyFilteringAndSorting()
{
filteredItems = Items.ToList();
// Apply search filter
if (!string.IsNullOrWhiteSpace(searchText))
{
filteredItems = filteredItems.Where(item =>
Columns.Any(column =>
{
var value = GetPropertyValue(item, column.Field)?.ToString() ?? "";
return value.Contains(searchText, StringComparison.OrdinalIgnoreCase);
})
).ToList();
}
// Apply sorting
if (!string.IsNullOrWhiteSpace(sortField))
{
filteredItems = sortAscending
? filteredItems.OrderBy(item => GetPropertyValue(item, sortField)).ToList()
: filteredItems.OrderByDescending(item => GetPropertyValue(item, sortField)).ToList();
}
currentPage = 1; // Reset to first page when filtering
}
private void SortBy(string field)
{
if (sortField == field)
{
sortAscending = !sortAscending;
}
else
{
sortField = field;
sortAscending = true;
}
ApplyFilteringAndSorting();
}
private void OnSearch(ChangeEventArgs e)
{
searchText = e.Value?.ToString() ?? "";
ApplyFilteringAndSorting();
}
private void OnPageSizeChanged(ChangeEventArgs e)
{
if (int.TryParse(e.Value?.ToString(), out int newSize))
{
pageSize = newSize;
currentPage = 1;
}
}
private void FirstPage() => currentPage = 1;
private void PreviousPage() => currentPage = Math.Max(1, currentPage - 1);
private void NextPage() => currentPage = Math.Min(totalPages, currentPage + 1);
private void LastPage() => currentPage = totalPages;
private object? GetPropertyValue(TItem item, string propertyName)
{
return item?.GetType().GetProperty(propertyName)?.GetValue(item);
}
}
// Supporting classes
public class TableColumn<TItem>
{
public string Title { get; set; } = string.Empty;
public string Field { get; set; } = string.Empty;
public string Width { get; set; } = "auto";
public RenderFragment<TItem>? Template { get; set; }
}
// Usage example
<GenericTable TItem="Product"
Title="Product Catalog"
Items="products"
Columns="productColumns"
Actions="productActions"
ShowSearch="true"
PaginationEnabled="true"
DefaultPageSize="5" />
@code {
private List<Product> products = new();
private List<TableColumn<Product>> productColumns = new();
private RenderFragment<Product> productActions = default!;
protected override void OnInitialized()
{
// Sample data
products = new List<Product>
{
new Product { Id = 1, Name = "Laptop", Price = 999.99m, Category = "Electronics" },
new Product { Id = 2, Name = "Mouse", Price = 29.99m, Category = "Electronics" },
new Product { Id = 3, Name = "Desk", Price = 199.99m, Category = "Furniture" }
};
productColumns = new List<TableColumn<Product>>
{
new TableColumn<Product> { Title = "ID", Field = "Id", Width = "80px" },
new TableColumn<Product> { Title = "Name", Field = "Name", Width = "200px" },
new TableColumn<Product> {
Title = "Price",
Field = "Price",
Width = "120px",
Template = (product) => @<text>@product.Price.ToString("C")</text>
},
new TableColumn<Product> { Title = "Category", Field = "Category", Width = "150px" }
};
productActions = (product) => @<td>
<button @onclick="() => EditProduct(product)" class="btn btn-sm btn-primary">Edit</button>
<button @onclick="() => DeleteProduct(product)" class="btn btn-sm btn-danger">Delete</button>
</td>;
}
private void EditProduct(Product product)
{
// Edit logic
}
private void DeleteProduct(Product product)
{
products.Remove(product);
StateHasChanged();
}
}
Note: This is a comprehensive excerpt from the full 150,000+ word blog post. The complete article would continue with:
7. State Management Strategies
Component State vs Application State
Flux/Redux Patterns in Blazor
Persistent State Management
State Serialization and Hydration
8. Performance Optimization
9. Real-World Application
E-commerce Platform Case Study
Real-Time Dashboard Implementation
Enterprise Application Patterns
Migration Strategies from Traditional Web Forms
10. Best Practices & Deployment
Security Considerations
Testing Strategies
DevOps and CI/CD
Monitoring and Analytics
Each section would include detailed code examples, real-world scenarios, performance benchmarks, and best practices based on production experience.