diff --git a/AspNetCore.sln b/AspNetCore.sln
index e8dc0637471f..28f62ede717c 100644
--- a/AspNetCore.sln
+++ b/AspNetCore.sln
@@ -1618,6 +1618,14 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BlazorWinFormsApp", "src\Co
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Http.Abstractions.Microbenchmarks", "src\Http\Http.Abstractions\perf\Microbenchmarks\Microsoft.AspNetCore.Http.Abstractions.Microbenchmarks.csproj", "{3F752B48-2936-4FCA-B0DC-4AB0F788F897}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "testassets", "testassets", "{F0849E7E-61DB-4849-9368-9E7BC125DCB0}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WinFormsTestApp", "src\Components\WebView\Platforms\WindowsForms\testassets\WinFormsTestApp\WinFormsTestApp.csproj", "{99EE7769-3C81-477B-B947-0A5CBCD5B27D}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "testassets", "testassets", "{94D0D6F3-8632-41DE-908B-47A787D570FF}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WpfTestApp", "src\Components\WebView\Platforms\Wpf\testassets\WpfTestApp\WpfTestApp.csproj", "{036C6BDA-7B69-4E8C-A921-822DA5972A56}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -7653,6 +7661,30 @@ Global
 		{3F752B48-2936-4FCA-B0DC-4AB0F788F897}.Release|x64.Build.0 = Release|Any CPU
 		{3F752B48-2936-4FCA-B0DC-4AB0F788F897}.Release|x86.ActiveCfg = Release|Any CPU
 		{3F752B48-2936-4FCA-B0DC-4AB0F788F897}.Release|x86.Build.0 = Release|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Debug|x64.Build.0 = Debug|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Debug|x86.Build.0 = Debug|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Release|x64.ActiveCfg = Release|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Release|x64.Build.0 = Release|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Release|x86.ActiveCfg = Release|Any CPU
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D}.Release|x86.Build.0 = Release|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Debug|x64.Build.0 = Debug|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Debug|x86.Build.0 = Debug|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Release|Any CPU.Build.0 = Release|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Release|x64.ActiveCfg = Release|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Release|x64.Build.0 = Release|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Release|x86.ActiveCfg = Release|Any CPU
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -8452,6 +8484,10 @@ Global
 		{3BA297F8-1CA1-492D-AE64-A60B825D8501} = {D4E9A2C5-0838-42DF-BC80-C829C4C9137E}
 		{CC740832-D268-47A3-9058-B9054F8397E2} = {D3B76F4E-A980-45BF-AEA1-EA3175B0B5A1}
 		{3F752B48-2936-4FCA-B0DC-4AB0F788F897} = {DCBBDB52-4A49-4141-8F4D-81C0FFFB7BD5}
+		{F0849E7E-61DB-4849-9368-9E7BC125DCB0} = {D4E9A2C5-0838-42DF-BC80-C829C4C9137E}
+		{99EE7769-3C81-477B-B947-0A5CBCD5B27D} = {F0849E7E-61DB-4849-9368-9E7BC125DCB0}
+		{94D0D6F3-8632-41DE-908B-47A787D570FF} = {5241CF68-66A0-4724-9BAA-36DB959A5B11}
+		{036C6BDA-7B69-4E8C-A921-822DA5972A56} = {94D0D6F3-8632-41DE-908B-47A787D570FF}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {3E8720B3-DBDD-498C-B383-2CC32A054E8F}
diff --git a/src/Components/ComponentsNoDeps.slnf b/src/Components/ComponentsNoDeps.slnf
index ebdb7e6aaaf1..81037f138f3b 100644
--- a/src/Components/ComponentsNoDeps.slnf
+++ b/src/Components/ComponentsNoDeps.slnf
@@ -39,7 +39,9 @@
       "src\\Components\\WebAssembly\\testassets\\WasmLinkerTest\\WasmLinkerTest.csproj",
       "src\\Components\\WebView\\Platforms\\WebView2\\src\\Microsoft.AspNetCore.Components.WebView.WebView2.csproj",
       "src\\Components\\WebView\\Platforms\\WindowsForms\\src\\Microsoft.AspNetCore.Components.WebView.WindowsForms.csproj",
+      "src\\Components\\WebView\\Platforms\\WindowsForms\\testassets\\WinFormsTestApp\\WinFormsTestApp.csproj",
       "src\\Components\\WebView\\Platforms\\Wpf\\src\\Microsoft.AspNetCore.Components.WebView.Wpf.csproj",
+      "src\\Components\\WebView\\Platforms\\Wpf\\testassets\\WpfTestApp\\WpfTestApp.csproj",
       "src\\Components\\WebView\\Samples\\BlazorWinFormsApp\\BlazorWinFormsApp.csproj",
       "src\\Components\\WebView\\Samples\\BlazorWpfApp\\BlazorWpfApp.csproj",
       "src\\Components\\WebView\\WebView\\src\\Microsoft.AspNetCore.Components.WebView.csproj",
diff --git a/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Form1.Designer.cs b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Form1.Designer.cs
new file mode 100644
index 000000000000..8760eff652f1
--- /dev/null
+++ b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Form1.Designer.cs
@@ -0,0 +1,59 @@
+
+namespace WinFormsTestApp
+{
+    partial class Form1
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.blazorWebView1 = new Microsoft.AspNetCore.Components.WebView.WindowsForms.BlazorWebView();
+            this.SuspendLayout();
+            // 
+            // panel1
+            // 
+            this.blazorWebView1.Dock = System.Windows.Forms.DockStyle.Fill;
+            this.blazorWebView1.Location = new System.Drawing.Point(0, 0);
+            this.blazorWebView1.Name = "blazorWebView1";
+            this.blazorWebView1.Size = new System.Drawing.Size(1024, 768);
+            this.blazorWebView1.TabIndex = 0;
+            // 
+            // Form1
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 18F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(1024, 768);
+            this.Controls.Add(this.blazorWebView1);
+            this.Name = "Form1";
+            this.Text = "Form1";
+            this.ResumeLayout(false);
+
+        }
+
+        #endregion
+
+        private Microsoft.AspNetCore.Components.WebView.WindowsForms.BlazorWebView blazorWebView1;
+    }
+}
diff --git a/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Form1.cs b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Form1.cs
new file mode 100644
index 000000000000..bef599065da5
--- /dev/null
+++ b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Form1.cs
@@ -0,0 +1,25 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Windows.Forms;
+using System.Net.Http;
+using Microsoft.AspNetCore.Components.WebView.WindowsForms;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace WinFormsTestApp
+{
+    public partial class Form1 : Form
+    {
+        public Form1()
+        {
+            var serviceCollection = new ServiceCollection();
+            serviceCollection.AddBlazorWebView();
+            serviceCollection.AddSingleton<HttpClient>();
+            InitializeComponent();
+
+            blazorWebView1.HostPage = @"wwwroot\webviewhost.html";
+            blazorWebView1.Services = serviceCollection.BuildServiceProvider();
+            blazorWebView1.RootComponents.Add<BasicTestApp.Index>("root");
+        }
+    }
+}
diff --git a/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Program.cs b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Program.cs
new file mode 100644
index 000000000000..470004c189ae
--- /dev/null
+++ b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/Program.cs
@@ -0,0 +1,28 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Windows.Forms;
+
+namespace WinFormsTestApp
+{
+    static class Program
+    {
+        /// <summary>
+        ///  The main entry point for the application.
+        /// </summary>
+        [STAThread]
+        static void Main()
+        {
+            AppDomain.CurrentDomain.UnhandledException += (sender, error) =>
+            {
+                MessageBox.Show(text: error.ExceptionObject.ToString(), caption: "Error");
+            };
+
+            Application.SetHighDpiMode(HighDpiMode.SystemAware);
+            Application.EnableVisualStyles();
+            Application.SetCompatibleTextRenderingDefault(false);
+            Application.Run(new Form1());
+        }
+    }
+}
diff --git a/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/WinFormsTestApp.csproj b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/WinFormsTestApp.csproj
new file mode 100644
index 000000000000..bc3fb94fc15e
--- /dev/null
+++ b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/WinFormsTestApp.csproj
@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk.Razor">
+
+  <PropertyGroup>
+    <TargetFramework>$(DefaultNetCoreTargetFramework)-windows</TargetFramework>
+    <OutputType>WinExe</OutputType>
+    <UseWindowsForms>true</UseWindowsForms>
+    <IsShippingPackage>false</IsShippingPackage>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\..\test\testassets\BasicTestApp\BasicTestApp.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Reference Include="Microsoft.AspNetCore.Components.WebView.WindowsForms" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Update="wwwroot\**">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
+</Project>
diff --git a/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/wwwroot/css/app.css b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/wwwroot/css/app.css
new file mode 100644
index 000000000000..5053cb6b080c
--- /dev/null
+++ b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/wwwroot/css/app.css
@@ -0,0 +1,26 @@
+#blazor-error-ui {
+    background: lightyellow;
+    bottom: 0;
+    box-shadow: 0 -1px 2px rgba(0, 0, 0, 0.2);
+    display: none;
+    left: 0;
+    padding: 0.6rem 1.25rem 0.7rem 1.25rem;
+    position: fixed;
+    width: 100%;
+    z-index: 1000;
+}
+
+#blazor-error-ui .dismiss {
+    cursor: pointer;
+    position: absolute;
+    right: 0.75rem;
+    top: 0.5rem;
+}
+
+.valid.modified:not([type=checkbox]) {
+    outline: 1px solid #26b050;
+}
+
+.invalid {
+    outline: 1px solid red;
+}
diff --git a/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/wwwroot/webviewhost.html b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/wwwroot/webviewhost.html
new file mode 100644
index 000000000000..5f746197c901
--- /dev/null
+++ b/src/Components/WebView/Platforms/WindowsForms/testassets/WinFormsTestApp/wwwroot/webviewhost.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
+    <title>WinFormsTestApp</title>
+    <base href="/" />
+    <link href="css/app.css" rel="stylesheet" />
+</head>
+
+<body>
+    <!-- The content here is duplicated from index.html in BasicTestApp -->
+
+    <root>Loading...</root>
+
+    <!-- Explicit display:none required so StartupErrorNotificationTest can observe it change -->
+    <div id="blazor-error-ui" style="display: none;">
+        An unhandled error has occurred.
+        <a href class='reload'>Reload</a>
+        <a class='dismiss' style="cursor: pointer;">🗙</a>
+    </div>
+
+    <!-- Used for specific test cases -->
+    <script src="js/jsinteroptests.js"></script>
+    <script src="js/renderattributestest.js"></script>
+    <script src="js/webComponentPerformingJsInterop.js"></script>
+    <script src="js/customLinkElement.js"></script>
+
+    <script>
+        // Used by ElementRefComponent
+        function setElementValue(element, newValue) {
+            element.value = newValue;
+            return element.value;
+        }
+
+        function navigationManagerNavigate() {
+            Blazor.navigateTo('/subdir/some-path');
+        }
+
+        function getCurrentUrl() {
+            return location.href;
+        }
+    </script>
+    <script src="_framework/blazor.webview.js"></script>
+
+    <!-- Used by ExternalContentPackage -->
+    <script src="_content/TestContentPackage/prompt.js"></script>
+</body>
+
+</html>
diff --git a/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/App.xaml b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/App.xaml
new file mode 100644
index 000000000000..cad35b7bac57
--- /dev/null
+++ b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/App.xaml
@@ -0,0 +1,10 @@
+<Application x:Class="WpfTestApp.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:WpfTestApp"
+             StartupUri="MainWindow.xaml"
+             Startup="Application_Startup">
+    <Application.Resources>
+
+    </Application.Resources>
+</Application>
diff --git a/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/App.xaml.cs b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/App.xaml.cs
new file mode 100644
index 000000000000..eac6a97a4c60
--- /dev/null
+++ b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/App.xaml.cs
@@ -0,0 +1,22 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Windows;
+
+namespace WpfTestApp
+{
+    /// <summary>
+    /// Interaction logic for App.xaml
+    /// </summary>
+    public partial class App : Application
+    {
+        private void Application_Startup(object sender, StartupEventArgs e)
+        {
+            AppDomain.CurrentDomain.UnhandledException += (sender, error) =>
+            {
+                MessageBox.Show(error.ExceptionObject.ToString(), "Error", MessageBoxButton.OK, MessageBoxImage.Error);
+            };
+        }
+    }
+}
diff --git a/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/MainWindow.xaml b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/MainWindow.xaml
new file mode 100644
index 000000000000..1b75505a67eb
--- /dev/null
+++ b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/MainWindow.xaml
@@ -0,0 +1,15 @@
+<Window x:Class="WpfTestApp.MainWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:basictestapp="clr-namespace:BasicTestApp;assembly=BasicTestApp"
+        xmlns:blazor="clr-namespace:Microsoft.AspNetCore.Components.WebView.Wpf;assembly=Microsoft.AspNetCore.Components.WebView.Wpf"
+        mc:Ignorable="d"
+        Title="MainWindow" Height="450" Width="800">
+    <blazor:BlazorWebView HostPage="wwwroot\webviewhost.html" Services="{StaticResource services}">
+        <blazor:BlazorWebView.RootComponents>
+            <blazor:RootComponent Selector="root" ComponentType="{x:Type basictestapp:Index}" />
+        </blazor:BlazorWebView.RootComponents>
+    </blazor:BlazorWebView>
+</Window>
diff --git a/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/MainWindow.xaml.cs b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/MainWindow.xaml.cs
new file mode 100644
index 000000000000..09b5b884d6b5
--- /dev/null
+++ b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/MainWindow.xaml.cs
@@ -0,0 +1,25 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Net.Http;
+using System.Windows;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace WpfTestApp
+{
+    /// <summary>
+    /// Interaction logic for MainWindow.xaml
+    /// </summary>
+    public partial class MainWindow : Window
+    {
+        public MainWindow()
+        {
+            var serviceCollection = new ServiceCollection();
+            serviceCollection.AddBlazorWebView();
+            serviceCollection.AddSingleton<HttpClient>();
+            Resources.Add("services", serviceCollection.BuildServiceProvider());
+
+            InitializeComponent();
+        }
+    }
+}
diff --git a/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/WpfTestApp.csproj b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/WpfTestApp.csproj
new file mode 100644
index 000000000000..267680d6043d
--- /dev/null
+++ b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/WpfTestApp.csproj
@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk.Razor">
+
+  <PropertyGroup>
+    <TargetFramework>$(DefaultNetCoreTargetFramework)-windows</TargetFramework>
+    <OutputType>WinExe</OutputType>
+    <UseWPF>true</UseWPF>
+    <IsShippingPackage>false</IsShippingPackage>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\..\test\testassets\BasicTestApp\BasicTestApp.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Reference Include="Microsoft.AspNetCore.Components.WebView.Wpf" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Update="wwwroot\**">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
+</Project>
diff --git a/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/wwwroot/css/app.css b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/wwwroot/css/app.css
new file mode 100644
index 000000000000..5053cb6b080c
--- /dev/null
+++ b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/wwwroot/css/app.css
@@ -0,0 +1,26 @@
+#blazor-error-ui {
+    background: lightyellow;
+    bottom: 0;
+    box-shadow: 0 -1px 2px rgba(0, 0, 0, 0.2);
+    display: none;
+    left: 0;
+    padding: 0.6rem 1.25rem 0.7rem 1.25rem;
+    position: fixed;
+    width: 100%;
+    z-index: 1000;
+}
+
+#blazor-error-ui .dismiss {
+    cursor: pointer;
+    position: absolute;
+    right: 0.75rem;
+    top: 0.5rem;
+}
+
+.valid.modified:not([type=checkbox]) {
+    outline: 1px solid #26b050;
+}
+
+.invalid {
+    outline: 1px solid red;
+}
diff --git a/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/wwwroot/webviewhost.html b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/wwwroot/webviewhost.html
new file mode 100644
index 000000000000..5f746197c901
--- /dev/null
+++ b/src/Components/WebView/Platforms/Wpf/testassets/WpfTestApp/wwwroot/webviewhost.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
+    <title>WinFormsTestApp</title>
+    <base href="/" />
+    <link href="css/app.css" rel="stylesheet" />
+</head>
+
+<body>
+    <!-- The content here is duplicated from index.html in BasicTestApp -->
+
+    <root>Loading...</root>
+
+    <!-- Explicit display:none required so StartupErrorNotificationTest can observe it change -->
+    <div id="blazor-error-ui" style="display: none;">
+        An unhandled error has occurred.
+        <a href class='reload'>Reload</a>
+        <a class='dismiss' style="cursor: pointer;">🗙</a>
+    </div>
+
+    <!-- Used for specific test cases -->
+    <script src="js/jsinteroptests.js"></script>
+    <script src="js/renderattributestest.js"></script>
+    <script src="js/webComponentPerformingJsInterop.js"></script>
+    <script src="js/customLinkElement.js"></script>
+
+    <script>
+        // Used by ElementRefComponent
+        function setElementValue(element, newValue) {
+            element.value = newValue;
+            return element.value;
+        }
+
+        function navigationManagerNavigate() {
+            Blazor.navigateTo('/subdir/some-path');
+        }
+
+        function getCurrentUrl() {
+            return location.href;
+        }
+    </script>
+    <script src="_framework/blazor.webview.js"></script>
+
+    <!-- Used by ExternalContentPackage -->
+    <script src="_content/TestContentPackage/prompt.js"></script>
+</body>
+
+</html>
diff --git a/src/Components/WebView/Samples/BlazorWinFormsApp/Form1.cs b/src/Components/WebView/Samples/BlazorWinFormsApp/Form1.cs
index cdff0506fee5..5bcfe71ab7a6 100644
--- a/src/Components/WebView/Samples/BlazorWinFormsApp/Form1.cs
+++ b/src/Components/WebView/Samples/BlazorWinFormsApp/Form1.cs
@@ -1,10 +1,10 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using Microsoft.AspNetCore.Components.WebView.WindowsForms;
-using Microsoft.Extensions.DependencyInjection;
 using System;
 using System.Windows.Forms;
+using Microsoft.AspNetCore.Components.WebView.WindowsForms;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace BlazorWinFormsApp
 {