A list of common migration errors from .Net Core 2 or .Net Core 3.1 to .Net 6 or .Net 7

You may encounter these errors when migrating your project to .Net 6 or .Net 7. Below is the error.

1.  'The ConnectionString property has not been initialized.'

In .Net 6 or 7, use has to use the keyword ConnectionStrings instead of ConnectionString otherwise you will get an error, connection string property has not been initialized.

2. A connection was successfully established with the server, but then an error occurred during the login process. (provider: SSL Provider, error: 0 - The certificate chain was issued by an authority that is not trusted.)'

If you are getting the above error this means you need to make the connection string encrypted false in app settings. 

3. An unhandled exception occurred while processing the request. InvalidOperationException: Unable to resolve service for type 'Service.IService' while attempting to activate

In .Net 6 or 7, we don’t have a start-up file. So, you must include everything in Program.cs. file

// Register interface and classes

builder.Services.AddScoped<IHotelService, HotelService>();

 

In Program.cs file, Register dependency before builder.build() command. It will resolve your issue.

4. InvalidOperationException: Unable to resolve service for type 'Data.LocatorDBContext' while attempting to activate 'Service.HotelService'. or
System.AggregateException: 'Some services are not able to be constructed

If you are facing the above issue this means you have not resolved the context in the program.cs and have not included the connection string in the Program.cs. Add the below lines and it will resolve the dependency.

 

builder.Services.AddDbContext<LocatorDBContext>(options =>

        options.UseSqlServer(builder.Configuration.GetConnectionString("LocatorDB")));

For UseSQLserver keyword, you need to include Nuget package.

Microsoft.EntityFrameworkcore.SQLServer

5. System.InvalidOperationException: 'No service for type 'Microsoft.AspNetCore.Mvc.ViewFeatures.ITempDataDictionaryFactory' has been registered.'

This means you have not registered MVC views in Program.cs file. Just add the below line in program.cs file. 

builder.Services.AddControllersWithViews();

6. No web page was found for the web address: http://localhost:5242/hotel/index

This error will occur if you have not registered routing in the program.cs file. Include the below line and it will work.

 

app.MapControllerRoute(

    name: "default",

    pattern: "{controller=Hotel}/{action=Index}/{id?}");

This will resolve the issue. I hope you like the article.

Ajax Form in Asp.Net Core MVC and Validations

Let's learn how to send a request to the Controller using Ajax. Sending requests to the Controller is a common need. Here we will learn how we can send the request through ajax. The first step is to include scripts in the folder.

Include Ajax Scripts

First, you need to ensure you have ajax-unobtrusive scripts in the folder. If not please download and add to the wwwroot or you can right-click on Wwwroot
Add-->Client Side Library

Search for ajax and install it. It will automatically add all the scripts in the www root.

Add Ajax in the form tag

 <form method="post" data-ajax="true" data-ajax-complete="mycompelte" data-ajax-success="mysuccess"  asp-action="AddHotel" asp-controller="Hotel" data-ajax-loading="#myloader">

data-ajax="true"

data-ajax-complete="mycompelte" (Complete Event, create javascript method of any name)

data-ajax-success="mysuccess" (Success Event, create javascript method of any name, In this example, I have used mysuccess method name)

asp-action="AddHotel" (MVC Method Name)

asp-controller="Hotel"  (MVC Controller Name)

data-ajax-loading="#myloader" (For Loader)

<div class="d-flex justify-content-center">

                <div role="Status" class="spinner-border" id="myloader" style="display:none;">

                    <span class="sr-only">Loading....</span>

                </div>

 </div>

Once you press the submit button it automatically sends the request to Add Hotel method asynchronously. Once the work is done it runs the success and completes the javascript method.

Now, let's learn how to add validation.

 public class HotelModel

    {

        public int HotelId { get; set; }

      

        [Required(ErrorMessage = "*")]

        public string HotelName { get; set; }

       

        [Required(ErrorMessage = "*")]

        public string Address { get; set; }      

}

For this, you need to use asp-validation-for property in the span tag, shown below. For input control, you can use @Html.TextBoxFor or input asp-for.

  <input asp-for="HotelName" />

 <span asp-validation-for="HotelName" class="text-danger"></span>

 @Html.TextBoxFor(d => d.Address,new{style="width:75%;"})

<span asp-validation-for="Address" class="text-danger"></span>

Also, you need to include the necessary files to run the validations.

1. JQuery
2. JQuery.Validate
3. JQuery.Validate. unobtrusive

<script src="~/lib/jquery/dist/jquery.min.js"></script>

<script src="~/lib/jquery-validation/dist/jquery.validate.min.js"></script>

<script src="~/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.min.js"></script>

<script type="text/javascript">

  function mysuccess(data) {

    }

</script>

That's all about this article.

Revert Git Changes Through Terminal / Command Prompt

 If you accidentally commit your code then don't worry you can revert your changes with a few commands. you can easily go to your last commit. Let's learn


Here is my code below. I have added one comment below in one of the files and I'll commit that.

I am saving that file with the below comment. Once its saved then let's run few commands.

1. Let's run the first command on the cmd prompt/terminal

 git log

It will give you the commit Id as shown in the snapshot below. Now we need to revert that changes.

2.  Copy the commit Id and run the second command.

git revert 59186cf31db4c520a6cf68343fb55843d0a369b8

You can see the comment has been removed from the code

3. Git changes will show you revert changes. You need to commit to that and that's it.

If you permanently delete the changes and remove them from history as well then follow the next article.

https://setiasunny.blogspot.com/2023/01/git-remove-last-commit-or-go-to.html

Hope you will like the article.

GIT remove last commit or go to previous commit

 If you commit the changes by mistake and want to remove that commit or want to go to the last commit then here are some simple commands.

In my example, I have added comments in the code and committed it.

Step 1: Run the command on Command Prompt / Terminal

    git log --oneline

It will display all the recent commits. In my example, I have recently committed "7897e22". Not, I want to go to the previous commits.


Step 2: Run the next command
    

            git reset head~1  (or)

            git reset 0e18a7c

Either you can go to the previous commit by (head~1) or you can specify the Id by checking from the git log.

You can use any one of the above commands.

Step 3: Once you run this command, you can see your changes in the Git Changes. If you want to delete all the changes then You can run the reset hard command. Please run this command carefully. If will remove all the recent changes.

       git reset --hard

Now, if you will check the git log again, you can see recent commit has been removed from the log.

If you only want to revert the changes and do not want to delete them from the log then you can follow the below article.

https://setiasunny.blogspot.com/2023/01/revert-git-changes-through-terminal.html

I hope you like the article. Thank you for reading this.