ASP.NET

https://learn.microsoft.com/en-us/aspnet/
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### Start HttpRepl

Source: https://learn.microsoft.com/en-us/aspnet/core/web-api/http-repl

Starts the HttpRepl tool after installation.

```console
httprepl

```

--------------------------------

### Start Web Host with URL and IRouteBuilder

Source: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/host/web-host

Starts the host with a URL and an IRouteBuilder, responding on http://localhost:8080 instead of the default port. Same routing behavior as the previous example.

```csharp
using (var host = WebHost.Start("http://localhost:8080", router => router
    .MapGet("hello/{name}", (req, res, data) => 
        res.WriteAsync($"Hello, {data.Values["name"]}!"))
    .MapGet("buenosdias/{name}", (req, res, data) => 
        res.WriteAsync($"Buenos dias, {data.Values["name"]}!"))
    .MapGet("throw/{message?}", (req, res, data) => 
        throw new Exception((string)data.Values["message"] ?? "Uh oh!"))
    .MapGet("{greeting}/{name}", (req, res, data) => 
        res.WriteAsync($"{data.Values["greeting"]}, {data.Values["name"]}!"))
    .MapGet("", (req, res, data) => res.WriteAsync("Hello, World!"))))
{
    Console.WriteLine("Use Ctrl-C to shutdown the host...");
    host.WaitForShutdown();
}
```

--------------------------------

### Example URLs for product categories

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Shows the original URL with query string and the routed URL that renders the same information.

```Console
http://website/products.aspx?categoryid=12

```

```Console
http://website/products/software

```

--------------------------------

### Example request URL for route data

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

This console output shows a sample request URL that triggers the route data example. When this request is made, the word 'scott' is rendered in the search.aspx page.

```Console
http://localhost/search/scott/

```

--------------------------------

### Configure application pool for auto-start in applicationHost.config

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Sets an application pool to start automatically by setting startMode to AlwaysRunning in applicationHost.config.

```XML
<applicationpools>
  <add name="MyApplicationPool" startMode="AlwaysRunning" />
</applicationpools>

```

--------------------------------

### HTML rendered by LayoutTemplate example

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

The HTML output of the LayoutTemplate example, showing that only a span element is rendered when templates are empty. This gives full control over virtually all generated content.

```HTML
<span>
</span>

```

--------------------------------

### CreateUserWizard with LayoutTemplate and placeholders

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

ASP.NET 4 example using a LayoutTemplate with placeholder controls (headerPlaceholder, sideBarPlaceholder, wizardStepPlaceholder, navigationPlaceholder) to control the Wizard control's rendering. The placeholders are replaced at run time by the corresponding template contents.

```ASP.NET
<asp:CreateUserWizard ID="CreateUserWizard1" runat="server" ActiveStepIndex="1"> 
  <LayoutTemplate> 
    <asp:PlaceHolder ID="headerPlaceholder" runat="server" /> 
    <asp:PlaceHolder ID="sideBarPlaceholder" runat="server" /> 
    <asp:PlaceHolder id="wizardStepPlaceholder" runat="server" /> 
    <asp:PlaceHolder id="navigationPlaceholder" runat="server" /> 
  </LayoutTemplate> 
  <HeaderTemplate> 
    Header 
  </HeaderTemplate> 
  <WizardSteps> 
    <asp:CreateUserWizardStep runat="server"> 
      <ContentTemplate> 
      </ContentTemplate> 
    </asp:CreateUserWizardStep> 
    <asp:CompleteWizardStep runat="server"> 
      <ContentTemplate> 
      </ContentTemplate> 
    </asp:CreateUserWizardStep> 
  </WizardSteps> 

</asp:CreateUserWizard>

```

--------------------------------

### Data annotations for email and URL fields

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

C# example showing how to mark properties with DataType attributes for EmailAddress and Url. These attributes cause Dynamic Data to use the new EmailAddress.ascx and Url.ascx field templates.

```C#
[DataType(DataType.EmailAddress)] 
public object HomeEmail { get; set; } 

[DataType(DataType.Url)] 
public object Website { get; set; }

```

--------------------------------

### httpRuntime maxUrlLength and maxQueryStringLength attributes

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Configure the maximum URL path length and query string length using the maxUrlLength and maxQueryStringLength attributes. This example sets maxUrlLength to 260 and maxQueryStringLength to 2048.

```XML
<httpRuntime maxUrlLength="260" maxQueryStringLength="2048" />
```

--------------------------------

### Generated URL from RouteUrl expression

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

This console output shows the URL generated by the RouteUrl expression example. ASP.NET automatically works out the correct route based on the input parameters.

```Console
http://localhost/search/scott

```

--------------------------------

### Example control ID from rendered HTML

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

The resulting control ID for the input element shown in the previous HTML example, illustrating the long ID generated by the AutoID algorithm.

```Console
ctl00_ContentPlaceHolder1_ParentPanel_NamingPanel1_TextBox1
```

--------------------------------

### web.release.config transform with Replace

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Shows a portion of a web.release.config file that uses the Replace keyword to replace the connectionString node in Web.config during deployment. The example specifies a connectionStrings element with xdt:Transform="Replace" and an add element for BlogDB.

```XML
<connectionStrings xdt:Transform="Replace"> 
  <add name="BlogDB" connectionString="connection string detail]" /> 

</connectionStrings>
```

--------------------------------

### Select output-cache provider per control with providerName attribute

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Use the new providerName attribute in a control directive to declaratively choose a different output-cache provider for a Web user control. This example sets the DiskCache provider for a control with 60-second duration.

```ASP.NET
<%@ OutputCache Duration="60" VaryByParam="None" providerName="DiskCache" %>

```

--------------------------------

### sessionState compressionEnabled configuration

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Set compressionEnabled to true in the sessionState element to compress serialized session state using GZipStream. This example uses SqlServer mode with a specified connection string.

```XML
<sessionState
  mode="SqlServer"
  sqlConnectionString="data source=dbserver;Initial Catalog=aspnetstate"
  allowCustomSqlDatabase="true"
  compressionEnabled="true"
/>
```

--------------------------------

### GridView ClientID Format with RowClientIDRowSuffix

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Example output format for a GridView control when RowClientIDRowSuffix is set to 'ProductName, ProductId'. The rendered client ID combines the specified columns, resulting in a format like 'rootPanel_GridView1_ProductNameLabel_Chai_1'.

```Console
rootPanel_GridView1_ProductNameLabel_Chai_1

```

--------------------------------

### ListView control without layout template (ASP.NET 4)

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Shows the simplified ListView markup in ASP.NET 4 that does not require a layout template. This replaces the previous example's markup.

```ASP.NET
<asp:ListView ID="ListView1" runat="server"> 
  <ItemTemplate> 
    <% Eval("LastName")%> 
  </ItemTemplate> 

</asp:ListView>

```

--------------------------------

### ListView ClientID Format with ClientIDRowSuffix

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Example output format for a ListView control when ClientIDRowSuffix is set to 'ProductName'. The rendered client ID appends the specified column value, resulting in a format like 'rootPanel_ListView1_ProductNameLabel_1', where the trailing 1 is derived from the product ID of the current data item.

```Console
rootPanel_ListView1_ProductNameLabel_1

```

--------------------------------

### DynamicHyperLink control example

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

ASP.NET markup for a DynamicHyperLink control that creates a link to the List page for the Products table. The link is generated based on routes defined in Global.asax, and the control automatically uses the default table name.

```ASP.NET
<asp:DynamicHyperLink ID="ListHyperLink" runat="server" 
    Action="List" TableName="Products"> 
    Show all products 
</asp:DynamicHyperLink>

```

--------------------------------

### Custom entity template markup for Products

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Example markup for a custom entity template that displays specific fields (ProductName and Category) using DynamicControl controls. This template is used for the Products data object.

```ASP.NET
<tr> 
  <td>Name</td> 
  <td><asp:DynamicControl runat="server" DataField="ProductName" /></td> 
  <td>Category</td> 
  <td><asp:DynamicControl runat="server" DataField="Category" /></td> 

</tr>

```

--------------------------------

### Use MemoryCache.Default with HostFileChangeMonitor in Windows Forms

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Shows how to use the new System.Runtime.Caching.MemoryCache class in a Windows Forms application without referencing System.Web.dll. The example stores file contents in the default cache instance, using a CacheItemPolicy with a HostFileChangeMonitor to expire the entry when the file changes. Requires a file at c:\data.txt.

```C#
private void btnGet_Click(object sender, EventArgs e) 
{ 
    //Obtain a reference to the default MemoryCache instance. 
    //Note that you can create multiple MemoryCache(s) inside 
    //of a single application. 
    ObjectCache cache = MemoryCache.Default; 

    //In this example the cache is storing the contents of a file string 
    fileContents = cache["filecontents"] as string;

    //If the file contents are not currently in the cache, then 
    //the contents are read from disk and placed in the cache. 
    if (fileContents == null) 
    {
        //A CacheItemPolicy object holds all the pieces of cache 
        //dependency and cache expiration metadata related to a single 
        //cache entry. 
        CacheItemPolicy policy = new CacheItemPolicy(); 

        //Build up the information necessary to create a file dependency. 
        //In this case we just need the file path of the file on disk. 
        List filePaths = new List(); 
        filePaths.Add("c:\\data.txt"); 

        //In the new cache API, dependencies are called "change monitors". 
        //For this example we want the cache entry to be automatically expired 
        //if the contents on disk change. A HostFileChangeMonitor provides 
        //this functionality. 
        policy.ChangeMonitors.Add(new HostFileChangeMonitor(filePaths)); 

        //Fetch the file's contents 
        fileContents = File.ReadAllText("c:\\data.txt"); 

        //And then store the file's contents in the cache 
        cache.Set("filecontents", fileContents, policy); 

    } 
    MessageBox.Show(fileContents); 
}

```

--------------------------------

### Override GetOutputCacheProviderName in Global.asax

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Programmatically select an output-cache provider per HTTP request by overriding GetOutputCacheProviderName. This example returns "DiskCache" for requests ending in "Advanced.aspx", otherwise falls back to the base implementation.

```C#
public override string GetOutputCacheProviderName(HttpContext context)
{
    if (context.Request.Path.EndsWith("Advanced.aspx"))
       return "DiskCache";
    else
        return base.GetOutputCacheProviderName(context);
}

```

--------------------------------

### Set meta tags in head element with runat=server

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/aspnet4/overview

Place meta tags for keywords and description inside the head element with runat="server" so that the Page.MetaKeywords and Page.MetaDescription properties can control them. If no matching meta tags exist, they are added on render; if they exist, the properties get and set their contents.

```ASP.NET
<head id="Head1" runat="server"> 
  <title>Untitled Page</title> 
  <meta name="keywords" content="These, are, my, keywords" /> 
  <meta name="description" content="This is the description of my page" /> 
</head>
```

--------------------------------

### Basic routing with MapGet in Startup.Configure

Source: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/routing

Basic routing setup in Startup.Configure. Registers UseRouting and UseEndpoints, and defines a single MapGet endpoint for the root URL that writes "Hello World!" to the response. If the request method is not GET or the URL is not /, no route matches and an HTTP 404 is returned.

```csharp
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }

    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapGet("/", async context =>
        {
            await context.Response.WriteAsync("Hello World!");
        });
    });
}

```

--------------------------------

### Install .NET Framework without remapping ASP.NET applications

Source: https://learn.microsoft.com/en-us/aspnet/whitepapers/side-by-side-with-10

Use this command to start the .NET Framework installation while preventing automatic remapping of all existing ASP.NET applications to the newer version. The /noaspupgrade option is used with the Dotnetfx.exe setup program.

```command
Dotnetfx.exe /c:"install /noaspupgrade?"
```

--------------------------------

### Start Nginx service with sudo service nginx start

Source: https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/linux-nginx

Explicitly starts Nginx after a first-time installation. The installer creates a systemd init script that runs Nginx as a daemon on system startup, but the service must be started manually after installation.

```bash
sudo service nginx start

```

--------------------------------

### Migrated Startup.Configure with UseEndpoints

Source: https://learn.microsoft.com/en-us/aspnet/core/migration/22-to-30

Updated version of the previous Startup.Configure example, replacing UseSignalR and UseMvc with UseEndpoints and using UseRouting, UseCors, UseAuthentication, and UseAuthorization in the recommended order.

```csharp
public void Configure(IApplicationBuilder app)
{
    ...

    app.UseStaticFiles();

    app.UseRouting();

    app.UseCors();

    app.UseAuthentication();
    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapHub<ChatHub>("/chat");
        endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}/{id?}");
    });
}

```

--------------------------------

### ASP.NET Core 2.2 Startup.Configure example

Source: https://learn.microsoft.com/en-us/aspnet/core/migration/22-to-30

Example of Startup.Configure in a typical ASP.NET Core 2.2 app, using UseSignalR and UseMvc.

```csharp
public void Configure(IApplicationBuilder app)
{
    ...

    app.UseStaticFiles();

    app.UseAuthentication();

    app.UseSignalR(hubs =>
    {
        hubs.MapHub<ChatHub>("/chat");
    });

    app.UseMvc(routes =>
    {
        routes.MapRoute("default", "{controller=Home}/{action=Index}/{id?}");
    });
}

```

--------------------------------

### LibMan install output

Source: https://learn.microsoft.com/en-us/aspnet/core/tutorials/signalr

Example output from the libman install command, showing the download and installation of the SignalR client library.

```console
Downloading file https://unpkg.com/@microsoft/signalr@latest/dist/browser/signalr.js...
wwwroot/js/signalr/dist/browser/signalr.js written to disk
Installed library "@microsoft/signalr@latest" to "wwwroot/js/signalr"

```

--------------------------------

### StartWith(Action<IApplicationBuilder> app) Host Startup

Source: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/host/web-host

Starts the host with a delegate that configures an IApplicationBuilder. The app responds on http://localhost:5000 with "Hello World!". WaitForShutdown blocks until Ctrl-C/SIGINT or SIGTERM is issued.

```csharp
using (var host = WebHost.StartWith(app => 
    app.Use(next => 
    {
        return async context => 
        {
            await context.Response.WriteAsync("Hello World!");
        };
    })))
{
    Console.WriteLine("Use Ctrl-C to shut down the host...");
    host.WaitForShutdown();
}

```

--------------------------------

### Output of libman install command

Source: https://learn.microsoft.com/en-us/aspnet/core/tutorials/signalr

Example output from the libman install command. Shows the files written to disk and the confirmation message for the installed library.

```console
wwwroot/js/signalr/dist/browser/signalr.js written to disk
wwwroot/js/signalr/dist/browser/signalr.js written to disk
Installed library "@microsoft/signalr@latest" to "wwwroot/js/signalr"
```

--------------------------------

### Migrate Startup.Configure with UseRouting and UseEndpoints

Source: https://learn.microsoft.com/en-us/aspnet/core/migration/22-to-30

Shows the recommended order for middleware in Startup.Configure: UseStaticFiles before UseRouting, and UseAuthentication, UseAuthorization, and UseCors between UseRouting and UseEndpoints.

```csharp
public void Configure(IApplicationBuilder app)
{
  ...

  app.UseStaticFiles();

  app.UseRouting();
  app.UseCors();

  app.UseAuthentication();
  app.UseAuthorization();

  app.UseEndpoints(endpoints => {
     endpoints.MapControllers();
  });


```

--------------------------------

### Class library hosting startup (ServiceKeyInjection)

Source: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/host/platform-specific-configuration

Defines a hosting startup in a class library. The class implements IHostingStartup and uses ConfigureAppConfiguration with AddInMemoryCollection to add two configuration keys (DevAccount_FromLibrary and ProdAccount_FromLibrary) to the app's configuration.

```csharp
[assembly: HostingStartup(typeof(HostingStartupLibrary.ServiceKeyInjection))]

namespace HostingStartupLibrary
{
    public class ServiceKeyInjection : IHostingStartup
    {
        public void Configure(IWebHostBuilder builder)
        {
            builder.ConfigureAppConfiguration(config =>
            {
                var dict = new Dictionary<string, string>
                {
                    {"DevAccount_FromLibrary", "DEV_1111111-1111"},
                    {"ProdAccount_FromLibrary", "PROD_2222222-2222"}
                };

                config.AddInMemoryCollection(dict);
            });
        }
    }
}
```

--------------------------------

### Configure HostOptions ServicesStartConcurrently and ServicesStopConcurrently

Source: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/host/hosted-services

Configure hosted service start and shutdown behavior. The start example enables concurrent startup; the stop example enables concurrent shutdown. These are separate configuration options for HostOptions.

```C#
builder.Services.Configure<HostOptions>(options =>
{
    options.ServicesStartConcurrently = true;
});

```

```C#
builder.Services.Configure<HostOptions>(options =>
{
    options.ServicesStopConcurrently = true;
});

```

--------------------------------

### Install @angular/router

Source: https://learn.microsoft.com/en-us/aspnet/core/client-side/spa-services

Install the client-side routing npm package. Example uses Angular's router.

```console
npm i -S @angular/router

```
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