MS Visual Studio 2022 (currently v17.4), e.g. within a simple C# .NET console app, becomes nearly unresponsive, taking multiple seconds while typing a few characters into the editor.

Solution/Workaround

1. Watch the current background tasks VS is running at the moment (bottom left), and make sure every task finishes within a few seconds.
   • If you experience e.g. a very long indexing of project files, this could be suspicious.
2. Reset VS settings to default:
   • devenv /ResetSettings
   • devenv /ResetUserData
3. Delete .vs subfolder of your project
4. Disable project cache:
   • Tools -> Options -> Environment -> Preview Features -> Use the project cache …

This should improve the editor’s AutoComplete feature a lot.

If not, have a look at the references, there are a few additional option tweaks which might be helpful.

References

https://stackoverflow.com/questions/72237599/how-to-disable-that-new-filecontentindex-folder-and-vsidx-files-in-vs-2022

https://superuser.com/questions/1663409/how-to-fully-reset-all-visual-studio-settings-to-factory-defaults

https://stackoverflow.com/questions/73787513/what-is-vsidx-in-visual-studio-and-why-is-it-autogenerated

https://www.reddit.com/r/VisualStudio/comments/zm252q/vs_2022_very_laggy_and_slow/

Scenario

You try to publish your ASP.NET Core site to another Windows server running IIS.

Error messages:

Event 1000 / IIS AspNetCore Module: Application ‘MACHINE/WEBROOT/APPHOST/DEFAULT WEB SITE’ with physical root ‘C:\inetpub\wwwroot\’ failed to start process with commandline ‘”dotnet” .\yourproject.dll’, ErrorCode = ‘0x80004005 : 80008083.

Event 1004/ IIS AspNetCore Module: Warning: Could not create stdoutLogFile \\?\C:\inetpub\wwwroot\logs\stdout_4460_201731417238.log, ErrorCode = -2147024893.

Solution

To get a better error description, first correct the 1004 error, i.e. create a directory C:\inetpub\wwwroot\logs and set write permissions.

Afterwards, reload the site and open the logfile there. In my case, it showed this error:

The specified framework ‘Microsoft.NETCore.App’, version ‘1.1.1’ was not found.

– Check application dependencies and target a framework version installed at:

C:\Program Files\dotnet\shared\Microsoft.NETCore.App

– The following versions are installed:

1.0.3

1.1.0

– Alternatively, install the framework version ‘1.1.1’.

In fact, local Visual Studio 2017 RC had been upgraded to 2017 RTM and the framework version of the project was also upgraded.

So basically, before you deploy/publish your project make sure your remote server runs exactly the same version of “.NET Core Windows Server Hosting”.

You get the latest packages here.

E.g. if your remote IIS server was already configured before you upgraded anything, simply uninstall the previous .NET Core Runtime(s) via Programs & Features, then install the latest .NET Core Runtime x.x.x, to be exact the “Windows Server Hosting (x64 & x86)” package.[:]

As a workaround, use this extension method:

using System.Security.Claims;

namespace myproject.Common
{
    public static class ExtensionMethods
    {
        /// <summary>
        /// User ID
        /// </summary>
        /// <param name="user"></param>
        /// <returns></returns>
        public static string getUserId(this ClaimsPrincipal user)
        {
            if (!user.Identity.IsAuthenticated)
                return null;

            ClaimsPrincipal currentUser = user;
            return currentUser.FindFirst(ClaimTypes.NameIdentifier).Value;
        }

    }
}

Usage:

using myproject.Common;

...

var userId = User.getUserId();

 [:]

As a .NET Core MVC sample for single elements, you would write code like

@Html.TextBoxFor(m => m.StartTime, new { @class = "form-control", @type = "datetime"  })

Or, if you use tools like the bootstrap-datetimepicker for a comfortable date and time input, there would be even more DIVs:

<div class='input-group date' id='datetimepickerStarttime'>
    
    @Html.TextBoxFor(m => m.StartTime, new { @class = "form-control", @type = "datetime"  })

    <span class="input-group-addon">
        <span class="glyphicon glyphicon-calendar"></span>
    </span>
</div>

How to use templates

You can specify EditorTemplates for certain types or models. The same behavior works e.g. for DisplayTemplates (DisplayFor()). I will explain how to create an EditorTemplate for type DateTime.

First, create a folder and an empty file: \Views\Shared\EditorTemplates\DateTime.cshtml

Paste this code into it:

<div class='input-group date' id='@("datetimepicker"+ViewData.TemplateInfo.HtmlFieldPrefix)'>
    
    @Html.TextBox("", ViewData.TemplateInfo.FormattedModelValue, new { @class = "form-control", type = "datetime" })

    <span class="input-group-addon">
        <span class="glyphicon glyphicon-calendar"></span>
    </span>
</div>

Afterwards, you can simply write

@Html.EditorFor(m => m.StartTime)

into your main cshtml file to get the full template loaded:

For JavaScript/jQuery access, use the value we created in the first line of the template, datetimepicker[yourModelPropertyName], in this case “datetimepickerStartTime”.

Example:

$('#datetimepickerStartTime').datetimepicker();

 [:]

One solution is to create the <select> tag yourself:

<select name="@Html.NameFor(m => m.mycol)" id="@Html.IdFor(m => m.mycol)" class="form-control">
                                                  
    @foreach (var item in ViewBag.myoptions)
    {
        <option value="@item.name" data-src-mycustomstuff="myStuff/@item.name"
                       selected="@(Model != null && item.name == Model.mycol)">
            @item.name_friendly
        </option>
    }
</select>

Reference

 [:]

As there is no way to set a “friendly name” value in the DB table structure directly, you might think of putting some additional data into the .Net database entity  model. This is not always a good idea, because data could get lost when you update your model structure from DB.

So the most useful way I found so far in ASP.Net is to use a combination of System.ComponentModel.DataAnnotations and Model Metadata.

Example

You have a table mytable in your model mymodel, which contains a column mycolumn. The friendly name for mycolumn should be “My Column”.

In your Models folder (Visual Studio Solution Explorer), create 2 class files called MetaData.cs and PartialClasses.cs.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;

namespace myproject.Models
{
    public class MetaData
    {
        public class mytableMetaData
        {
            [Display(Name = "My Column")]
            public object mycolumn;
            

        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;

namespace myproject.Models
{    
    [MetadataType(typeof(MetaData.mytableMetaData))]
    public partial class mytable
    {
    }
}

In your .cshtml file, use:

@Html.DisplayNameFor(m => m.mycolumn)

You should now see the friendly column name “My Column” in your browser.

E.g. “@Html.ValidationSummary()” now also uses the display name from Metadata.

If you refresh your model structure later, these two classes are not affected.

Reference[:]

In your SQL database table, you have e.g. a foreign key relation – a nullable column of one table references another table which contains the items for your DropDownList (HTML Select).

But by default, Html.DropDownListFor() does not have an option for the user to choose the NULL value.

Solution

Add a NULL option to your list before you call DropDownListFor().

In your View:

<div class="dropdown">
    Example
    @{
          var list = new SelectList(ViewBag.list, "name", "name_friendly", "(none)").ToList();
          list.Insert(0, new SelectListItem() { Value = null, Text = "(none)" });
     }
     @Html.DropDownListFor(yourFkTable => yourFkTable.chosenItem, list)
</div>

UPDATE 2016-07-16:

The above solution might case controller validation errors.

But there is a much easier way.

<div class="dropdown">
    Example
        @Html.DropDownListFor(yourFkTable => yourFkTable.chosenItem, list, "(none)")
</div>

If the third parameter is given, “(none)” will be converted into “<option value=””>“, which is accepted by your controller.

Also make sure your SQL column value allows null values.

Reference[:]

You have an SQL datatable which contains a BLOB column to save images direcly in your DB as binary and want to show the images on your website.

Solution

Create your EntityFramework and Controller with the common wizards and methods.

Because you cannot directly give a Byte Array to your browser, you have to edit your .cshtml file to insert the images directly into your HTML code as Base64 strings:

@foreach (var item in Model)
{
     @{
       String img64 = Convert.ToBase64String(item.image);
       String img64Url = string.Format("data:image/"+item.imagetype+";base64,{0}", img64); //imagetype can be e.g. gif, jpeg, png etc.
      }
      <img src="@img64Url"/>
}

A method which offers the images via Controller would be to add ActionResult methods (and/or parameters) for your images.

In your Controller:

public ActionResult GetImage()
{
    byte[] imageByteData = yourmodel.yourtable...yourImage;
    return File(imageByteData, "image/png"); 
}

//UPDATE 2016-06-07: 
//Some Browsers like IE do not seem to accept the ContentType parameter of File() and change it to GIF, which may result in lower image quality!
//Better use this code:
public ActionResult GetImage()
{
   System.IO.MemoryStream ms = new System.IO.MemoryStream();
   yourImage.Save(ms, resultImageType); //or use your Byte[] directly with Memorystream constructor
   ms.Position = 0;
   return new FileStreamResult(ms, "image/png");
}

Now the src attribute of the image tag should point to /Home/GetImage.

In your View:

<img src='@Url.Action("GetImage", "Home")'/>

Reference[:]