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I just downloaded Visual Studio Code and my Intellisense is not automatically working.
The two settings that control this seem to be set correctly:
"editor.quickSuggestions": true,
"editor.suggestOnTriggerCharacters": true,
I do get an Intellisense menu when i start typing and press "CTRL + Space", but this gives me a list of everything and not things specifically for my object.
What am i doing wrong?
If you have a workspace and for some reason have multiple folders you may need to 'help' omnisharp a bit. I initially had a big project and added a solution for it further on - ending up with TWO workspace folders (one to a startup project and one to the solution). After composing that setup I experienced only the first project to have intellisense working.
Solution to get intellisense working was to make sure omnisharp worked its way from the solution instead of the project:
Ctrl + Shift + p
Write "OmniSharp: Select Project" and press Enter.
Choose the solution workspace entry.
Inspiration gotten from 'swaner':
https://github.com/OmniSharp/omnisharp-vscode/issues/1889
Visual Studio Code's more advanced editing features (IntelliSense, refactoring tools, etc.) only work in C# files if you have a project.json file or *.sln file that VSCode is aware of. Open the folder (i.e. open the File menu and click Open Folder...) with the *.sln file or project.json and VSCode will attempt to find all project/solution files in the folder. If there are multiple projects, you may need to select one from the projects button on the right side of the status bar (bottom of the window).
From the VSCode website:
Selecting a project.json-file is opening a DNX-project and VSCode will load that project plus the referenced projects
Selecting a *.sln-file is opening a MSBuild-project. It will load the referenced *.csproj-projects and sibling or descendant project.json-files but no other project files that are referenced from the solution file.
Selecting a folder will make VSCode scan for *.sln and project.json files and VSCode will attempt to load them all.
If you are start your project with c#, then some time you haven't download extension.
Process by written
Ctrl + Shift + p.
Write "OmniSharp: Select Project" and press Enter.
Choose the solution workspace entry.
Then enable the c# extension for "OmniSharp : Project".
Process by image
Downgrading to 1.23.9 of the C# VS Code extension fixed the intellisense for me. So if nothing else is working for you, perhaps try installing an older version of the extension (doesn't necessarily have to be that exact one I mentioned). You can do this by selecting this option in VS Code:
As of the 0.5 version I have found that I need to close and re-open my working files to get some new intellisense information to start working for my own files. This usually happens after I have a file open that needs to use type information from another file I just created. Until I close and re-open them (within the editor) the intellisense doesn't always work.
Hopefully this is something that'll get fixed as the app matures.
Inorder to make the intelligence working, the Visual Studio Code extension OmniSharp should be there along with Mono. When you open a project/solution folder, the OmniSharp gets the project dependencies from either project.json or from the dotnet solution file (if the project/solution created with other versions of visual studio).
So, when you look at the omnisharp's output window after immediately opening the project/ solution folder, you may see the following lines
Starting OmniSharp server at 2017-9-18 09:26:44
Target: /Users/{username}/Source/{Your Solution Folder}/{Your Solution
file}.sln
OmniSharp server started wth Mono
Path: /Users/{username}/.vscode/extensions/ms-vscode.csharp-1.12.1/.omnisharp/run
PID: 5808
post that, you may see couple of lines coming up like below,
[info]: OmniSharp.MSBuild.MSBuildProjectSystem
Update project: {Your Project1 Name}
[info]: OmniSharp.MSBuild.MSBuildProjectSystem
Update project: {Your Project2 Name}
....
they mean that your projects are getting recognised by OmniSharp Extension.
If you get any error message informing you about timeout, please get into the settings of the Visual Studio Code, and add a configuration override like the one below:
"omnisharp.projectLoadTimeout": 200
I know it is too long to wait for 200 seconds. But don't worry, this won't stop you anymore working with project files. But, remember that the IntelliSense will be automatically available once all the projects in the folder are successfully loaded.
Feel free to extend the Timeout setting since it will help you getting intellisense even-though you are not getting it immediately.
Here is another link with the same solution: https://github.com/OmniSharp/omnisharp-vscode/issues/1585
Hope my information helps you! Enjoy your VSCode!
This case was for an existing project that was working fine before. Opened via the vs code "recent" history.
For dotnet core. I opened my project's *.csprog file, made no changes, and saved it via the vs code editor.
As soon as I saved, all of the intellisense stuff starting working again in my other files within that project.
Another troubleshooting strategy to try if none of the above works out is uninstalling Mono, which is unnecessary anyways if you're using .NET Core. I also experienced a sudden disappearance of Intellisense after pulling changes to one of our enterprise repos that included an upgrade from ASP.NET Core 2.0 to 2.1. Strangely, at the same time, Intellisense was working fine in another C# project repo running ASP.NET Core 2.2.
For the project in question, I was puzzled to see successful logs for each reboot of the Omnisharp server as well as perfectly clean builds and runs. The puzzlement increased as I compared these Omnisharp logs to those from the 2.2 project and found them effectively identical.
Upon uninstalling Mono, the one detail that changed is how Omnisharp started. Now it boots up from a shell script located at ~/.vscode/extensions/ms-vscode.csharp-1.19.0/.omnisharp/1.32.18/run. Previously, Mono itself was booting the server from the executable at ~/.vscode/extensions/ms-vscode.csharp-1.19.0/.omnisharp/1.32.18/omnisharp/Omnisharp.exe.
Other troubleshooting I attempted in this instance though to no avail:
dotnet clean / Deleting bin and obj directories
Updating launch.json to point at the proper /bin/Debug/netcoreapp2.1 build
directory
Wiping my local nuget cache
Restarting Omnisharp
Uninstalling and reinstalling VS Code, as well as bumping back a version from 1.33.1 as the breakage coincided oddly with the March 2019 update
Uninstalling and reinstalling the C# VS Code extension, as well as bumping back a version from 1.19.0 given other users' reports of said version interfering with Intellisense for certain projects*
Adding a global.json file at project root to override default utilization of latest .NET Core SDK (mine was 2.2.105) and run instead using 2.1.302 in concert with the project's version
Wiping/rebuilding the project .sln file
Specs: VS Code 1.33.1, C# Extension 1.19.0, MacOS High Sierra 10.13.6.
*NB: As it turns out, in another .NET Core 2.1 project with the same issues in VS Code as described above, uninstalling Mono alone did not fix things. I also did wind up needing to bump back the C# extension to v. 1.18.0 to recover Intellisense. Weird.
The issue I had was OmniSharp was an older version. I set the flag to update to latest version in Settings.json file. This ensures the extension is always the latest version.
"omnisharp.path": "latest"
And restarted VS code. That fixed it for me.
Simply reinstall the extension and restart the VSCode/PC.
I use Task Manager and kill the Visual Studio Code process, then restart Visual Studio Code, the intellisense shows and fixed.
I've had some good experiences in C# with this extension so far:
https://marketplace.visualstudio.com/items?itemName=jchannon.csharpextensions
This extension traverses up the folder tree to find the project.json or *.csproj and uses that as the parent folder to determine namespaces.
Try "Install Extension" from command Pallete - probably if C# intellisense is not there:
https://code.visualstudio.com/docs/customization/colorizer
if intellisense in not working for react js or javascript or node js this solution will help for windows
uninistall type script by typing npm uninstall -g typescript
install specific version of type script that is 3.3 by typing npm install -g typescript#3.3
add the typescript location in vscode by navigating to file > Preferences > settings > here search for edit in setting.json then add this path "typescript.tsdk": "/Users/yourusename/AppData/Roaming/npm/node_modules/typescript/lib"
settings.json should look someting like this
{
"editor.suggestSelection": "first",
"vsintellicode.modify.editor.suggestSelection":"automaticallyOverrodeDefaultValue",
"typescript.tsdk": "/Users/yourusername/AppData/Roaming/npm/node_modules/typescript/lib"
}
I was able to fix this by changing the Api Compatibility Level from .Net Standard 2.0 to .NT 4.x. You can find this setting on Project Settings / Player.
After that, intellisense started working again.
This is because of C# extension issue.
Reinstall the extension will work.
https://code.visualstudio.com/docs/editor/intellisense
https://marketplace.visualstudio.com/items?itemName=ms-dotnettools.csharp
I fixed this with a multiple project solution in .net5 / .net core 3.1 by
opening each project (not the sln folder) in VSCODE. This then prompts to add the resources/ .CSX? files to the project; enabling intellisense, per project. Finally close that window and reopen the solution folder and all works as expected.
See image
Add VSCode assets
Downgrading to 1.23.9 of C# for Visual Studio Code (powered by OmniSharp).
https://i.stack.imgur.com/VrdJl.png
After trying several things I looked at the OmniSharp logs only to realize that because I had two different sln files in my workspace. It had picked up the “other” one and thus wasn’t working. I deleted it, reopened vs code, and all is well again.
For me I had been working without internet for a long time. It had previously been working but then stopped. I closed+reopened VSCode with a stable wifi connection and the Output tab in VSCode popped up, displaying the the extensions were re-installing. After that it worked!
in my case , the extension wasn't enabled
I just had this happen (this being no code completion suggestions appearing). What resolved it for me was changing the VSCode Editor package in Unity to a previous version and then back to the current version.
For me, this was going from 1.2.0 to 1.1.3 and then back to 1.2.0. I believe removing and reinstalling 1.2.0 would have accomplished the same.
Window > Package Manager > Visual Studio Code Editor
I know this is probably the most obvious answer. But I had enough dealing with VS Code ridiculous bugs. You should be focusing on code, not the buggy IDE. Their documentation doesn't make it easy either to debug.
Steps for complete uninstallation:
Save your personalization files such as keybindings.json,
Just put it on GitHub or something so whenever you need have trouble with VS Code you simply just need to go to GitHub and copy-paste it.
Uninstall VS Code completely
When you uninstalled VS Code, it doesn't erase your extension files and some old settings. This is the cause of the re-installation ended up the same. Horrible move VS Code. For the list of the files that you must delete, you can check out this answer.
Go to their website and install the new one.
I hope this helps some people who are already had enough with the VS Code ridiculous bug.
In my case, the issue was not with VS Code settings. The error was due to a corrupted TEMP path configured in my PC's registry user profile environment settings.
I got this error from Help --> Toggle Developer Tools --> Console
The error was flagged in the console when I opened a new typescript file.
Unable to write file c:\Users\XXX\AppData\Local\Temp;C:\wamp64\bin\php\php5.6.25;C:\vufind-3.1.2\install.php\09cf49d8-af5b-42e9-8194-43f5b566be0f'
Obviously this path was corrupted. After updating the environment variables in registry settings, the VS code IntelliSense started working. Checking the console is a good start to find the root cause of this issue.
Earlier intellisense was working for Angular in VS-Code but for some reason (which I don't know) intellisense stopped working. I had extensions installed i.e. Angular Essentials and Angular Language Service etc. that were responsible for this intellisense and all that.
What I did?
I disabled the extensions, restarted VS Code and enabled them. It was all working fine as before.
If everything in VSCode is working ( No errors in output console, language server is working etc.) and built-in extensions are enabled. Still, if your IntelliSense is not working for normal .js files make sure variables are defined with a type identifier such as var d = new Date() or let d = new Date(). In my case, IntelliSense was not working for d = new Date() (No autocomplete for Date object 'd' APIs in this way) but started working fine when I specified a type before my variable names.
Download and install "Tool for Visual Studio 2019" as the C# extension under hood use the build tools: https://visualstudio.microsoft.com/downloads/
In my case, I had an extension installed (Explorer Exclude) to help me focus and hide certain files that I don't regularly work with within the Explorer.
I so happened to have disabled viewing *.sln, *.csproj and *.vsconfig files and folders, which apparently prevents VSCode from even knowing the file is there in the first place. Disabling these specific rules solved the problem instantly.
Took me ages to figure out... The more you know.
I solved it by uninstalling all SDK's (not sure if this is needed)
and installed 4.7.1 developer pack
win 10, vscode 1.63.2, unity 2020.3.25f1
I fixed this by installing .NET Framework 4.7.1 Developer Pack:
https://dotnet.microsoft.com/en-us/download/dotnet-framework/net471
I am using Visual Studio Code and I have already loaded C# OMNISharp plugin to my system and it works all fine in my existing project/solutions.
However, I just created a new solution and a new project in Visual Studio code and it sounds like for this particular solution, the Intellisense or any other Omnisharp features are just not working. I have tried following things:
Restarting Visual Studio Code
Disabling and enabling my OmniSharp Plug-in
Also, one thing that I noticed is that when a solution is created in Visual studio, it has a lot of code which looks like following:
Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{AEA16303-6991-4FF1-A3A9-72D892D7968C}"
EndProject
Basically, these are all project references. However, when a solution is created by Visual Studio Code then there is not any section like that. This solution runs and compiles fine, just that it looks fundamentally different than how a Visual Studio solution looks like.
However, nothing seems to be working. Is there anything that I can try to make it work? Any ideas ?
It's caused by adding *.sln and *.csproj to your "files.exclude" setting.
Try this:
Code -> Preferences -> Settings -> "omnisharp.useMono": true/false
Remove from setting file.
Or, Open your project with MonoDevelop or Visual Studio 2015/2017 first, then reopen VS-Code.
Edit 1: Try setting "omnisharp.useGlobalMono": never and then restarting the omnisharp server.
Credit: The_Wolf and kao peter
How did you created the project?
For the Intellisense to work properly the project needs to have a specific structure.
Assuming you have the .net core sdk for mac and the omnisharp extension installed:
Try the following:
Open your integrated terminal (View => Integrated terminal)
Create some new directory to host a test project say "testproj" e.g => mkdir testproj
use the dotnet cli to initialize the project => dotnet new console
See if you got intellisense.
Also i'd recommend watching the .net core on Mac introduction video.
In VS Code v1.43.2 adding following line to settings worked for me:
"omnisharp.useGlobalMono": "never"
The setting's value "never" had to be double-quoted otherwise it would be flagged in red. Even with the quotes, it remained highlighted in yellow. Not sure why, as all other options/values in there are blue. I presume this indicates some sort of warning, but it works.
(As an aside, I would love to understand what a "Globally installed mono" is. However my only interest here was getting IntelliSense working, so re: omnisharp I'm pleading 'newb'.)
This worked for me
"omnisharp.useGlobalMono": "never"
Were your new solution and projects created in a "OneDrive" folder in Windows 10? In latest Windows 10 release, the C# plugin can't start up when a project resides in a OneDrive folder with "File On-Demand" feature on. Please take a look at this issue on Github
I my case, the problem came from the resource folder of my project.
I had added a visual studio .sln file in the ressources to be used as a template but I somehow "variabilized" it with custom tags. OmniSharp tried to parse it and obviously failed, but no error poped up in VSCode, it was only visible in OmniSharp output.
The solution was to rename the template from .sln to .txt to prevent OmniSharp from loading it.
In my case, after installing C# extension, I had to click the setting icon on the extension and then click "Add to workspace recormendations"
I had this problem in 2022 and nothing mentioned above worked for me.
For me the problem was caused by VS Code and C# plugin being updated (in my case c# plugin to v1.25.0+) because in this version they made this:
.NET Framework builds of OmniSharp no longer ship with Mono or the MSBuild tooling (See announcement omnisharp-roslyn#2339). To ensure that the C# > > extension remains usable out of the box for .NET SDK projects, we have > changed the default value of omnisharp.useModernNet to true.
If you still need Unity or .NET Framework support, you can set > omnisharp.useModernNet to false in your VS Code settings and restart OmniSharp.
So entier problem was in omnisharp.useModernNet being set to true by default which renders entire plugin unfunctional but doing what they said and setting
omnisharp.useModernNet to false manually in .vscode > settings.json file solved this problem for me!
For more info, you can also read the entire official VS Code C# Plugin announcement under plugins Details section in VS Code or on this webpage as well!
I'm running my .NET 4.0 (C#) project in debug mode after I start VS2013. It runs just fine.
The second time I start it from VS, I get the Dialog box that says "Error while trying to run project: Unable to start program C:\path\to\file.exe"
The process is still alive in the Taskmanager when I dismiss the dialog box.
From Windows Explorer, I can run the program just fine. And after closing it, the process is gone too from the Task Manager.
A rebuild doesn't help.
Is this a common problem with a known solution?
I had an issue similar to this and I had to clear the component cache instruction can be found Here.
Hope this helps.
For my case, it cause by Platform target, you could force choose it to x86 or x64 which your project is:
Each Project's Properties > Build > Platform target
As I pointed out also here, the only solution that worked for me was to disable the ConEmu integration:
ConEmu → Settings → Integration → Default term → disable Force ConEmu as default terminal for console applications
Some users reported that it was enough for them to disable the Aggressive mode in that same settings tab; that wasn't the case for me though.
The topic is old, but this might help someone else.
So in my case I made a file in Visual Studio with .cp extension (accidentally deleted the last 'p') this made visual studio just "include" the the file and not mark it as a compilation unit, thus not compiling it, I looked the *.vcxproj file in a text editor and found out about this, so if you open the project file in a notepad or something just find your file at the bottom usually and change from <Item .../> to <ClCompile .../>
I was getting similar errors. I just had to restart visual studio. Sometime couple times a day.
I had a similar error and resolved it by cleaning the solution. Right-click the solution name in Solution Explorer and choose Clean Solution.
I found a solution here:
Please check "Use Managed Compatibility Mode" under Tools|->Options->Debugging->General.
I'm Brazilian, I don't speak English very well. I did this translation on google translator.
I know the topic is old, but it can still help someone.
I had this same problem in the following situation, I have a dual boot computer (linux debian 11 and windows 10). Inside debian, on my NTFS D disk, I created a folder to perform programming tests. After accessing that same folder with windows, I created a new project in visual studio inside that same folder that I had created in linux. The creation of the project went without problems, however when I tried to run the project (F5), I received the same error from this topic. I tried all the solutions I found on the internet, and nothing worked. I gave all permissions to my admin user and it still didn't work. Then I realized that even going straight to the folder where the application's executable was and clicking directly on it, I still received the access denied error message. So, I took the project out of the folder I had created in linux, and it worked. So, what I could conclude, is that because the folder where my project was was created in linux, for some reason, my windows didn't trust this folder, so it didn't allow running executables from inside that folder, even this one executable having been created by visual studio from within windows.
Just simply create a folder name as "projects" in c drive and copy paste the newly created project in it. Run the project by doing clean & Build or Rebuild method . It will work
open the folder which contains the solution in visual studio.
again, open your *.sln file by double clicking it inside the solution explore once opened try running the solution or rebuild the solution. once rebuild gets completed, it will open without error from next time.
My way of solving the error : error while trying to load project : Unable to start program and c:\Path\to\file.exe was simply by
First restart Visual Studio
Click the build icon
Select the rebuild option
Run the Program or Debug the Program
This was a weird one. Going to put what happened to me here because it might happen to someone else. Everything was fine with the app until suddenly after some fairly insignificant code changes I suddenly started getting this error. Visual Studio was compiling the executable just fine. But, the moment I tried to run it (either from Visual Studio or directly) the executable file would be automatically deleted right out of the Debug folder. Super odd--never seen anything like it. I began to get suspicious that perhaps an anti-virus or the OS was somehow identifying a checksum or some signature in the executable as "dangerous". Or perhaps some obscure compilation bug was corrupting the executable. So on a hunch I made another innocuous change (added a couple of lines of code to color code some text in a rich text box) and the problem went away.
In Visual Studio 2010, I have just one project that cannot be published using the "Publish Now" button.
If I publish using the menu option instead, it works fine. I can then increment the version number, click "Publish Now" (or use "Publish Wizard..."), and get this error:
Cannot publish because a project failed to build.
However, no other error message is given. I managed to get screenshots of the output screen before it clears and flips to the Error List tab, but there is no mention there of any error. Clean & Rebuild doesn't fix the problem.
What do these two options do differently? Why is the build failing one way but not the other?
Since "rebuild solution" and "clean Solution" are not solving these issues, it might be either logs or assemblies in Bin.
This error seems to be caused by various issues :
Solution 1. set the build log verbosity to Diagnostic from the menu Tools->Options->Project and Solutions->Build and Run in Visual Studio 2010.
After that, if you build and publish your project, you can see the detailed build log from the Output window. From there, we should get futher information about why it failed to build.
Solution 2. Do you have Google Desktop by chance? If you do, close the sidebar and try once.
Solution 3. Click here for an another solution
Solution 4. Do you work with people from other timezones ? Files modified in future time may also cause this issue. check this utility
Solution 5.
I suggest you to try running the Visual Studio in safemode that will force the visual studio loading only the default environment and services, and shipped versions of third party packages. If the problem disappears you may stuck with some version of IDE tools with bugs. update them then.
If nothing seems to work, try this.
*Solution 6*
After researching it, it appears that the built in build/publish script that Visual Studio (2010 in our case) uses has a flaw in the order that it does things. Most importantly it runs a cleanup on the OBJ directory deleting the target EXE file before the publish step can grab it.
The solution
This is somewhat of a hacky workaround, but it solved the problem for me.
The fix is to copy the file back to the /obj/ folder from the /bin/ folder right before the publish step. Unfortunately there is no way that I know to specify a BeforePublish event through the IDE, so you will have to edit the .vbproj file in a text editor.
Add the following section just before the final tag.
<Target Name="BeforePublish">
<Copy SourceFiles="$(TargetPath)" DestinationFolder="$(IntermediateOutputPath)" />
</Target>
Clean and Rebuild worked for me. It seems like Google desktop and some browser extenstions causing this bug often. looking for a security update is good way to go with this.
I eventually created a new branch, and that branch did not have this problem. I never discovered what the actual cause was.
Just recently, my Visual Studio 2010 stopped displaying IntelliSense suggestions automatically while I am typing. I can still press ctrl+space to get it to work, but it doesn't automatically show a list of suggestions like it used to. I have already tried disabling all my extensions, restarting VS and the computer, and I have checked all the appropriate settings (Options -> Text Editor -> C# -> IntelliSense) to make sure that it is set to offer suggestions after a character is typed.
Has anyone seen this behavior before? Does anyone have any other suggestions for how I can get IntelliSense to go back to the way things were before? If not, I might just have to do a fresh reinstall of VS...
In prose, in case you can't see the above image:
Open Tools > Options > Text Editor. If you're only having this issue with one language, find that language; if it's for everything, click "All Languages". Right at the top, there'll be a few options labeled "Auto list members", "Hide advanced members", and "Parameter information". Make sure all of those are enabled (though the second may be disabled; if so, ignore it).
I have found that at times even verifying the settings under Options --> Statement Completion (the answer above) doesn't work. In this case, saving and restarting Visual Studio will re-enable Intellisense.
Finally, this link has a list of other ways to troubleshoot Intellisense, broken down by language (for more specific errors).
http://msdn.microsoft.com/en-us/library/vstudio/ecfczya1(v=vs.100).aspx
I'll start off my noting that this hasn't happened since I upgraded my RAM. I was at 4GB and would often have multiple instances of VS open along with SSMS. I have since gone to 8GB and then 16GB.
Here's the steps I go through when I lose intellisense.
If only one file/window appears to be affected, close/reopen that file. If that doesn't work, try below.
In Visual Studio:
Click Tools->Options->Text Editor->All Languages->General
Uncheck "Auto list members"
Uncheck "Parameter information"
Check "Auto list members" (yes, the one you just unchecked)
Check "Parameter information" (again, the one you just unchecked)
Click OK
If this doesn't work, here's a few more steps to try:
Close all VS documents and reopen
If still not working, close/reopen solution
If still not working, restart VS.
For C++ projects:
MSDN has a few things to try: MSDN suggestions
The corrupt .ncb file seems most likely.
From MSDN:
Close the solution.
Delete the .ncb file.
Reopen the solution. (This creates a new .ncb file.)
Notes:
This issue does not appear to be specific to C# as C++ and VB users
report the same issue
Tested in VS 2013/2015
Steps to fix are:
Tools
Import and Export Settings
Reset all settings
Back up your config
Select your environment settings and finish
I also faced the same issue but in VS2013.
I did the below way to fix, It was worked fine.
Close all the opened Visual studio instance.
Then, go to "Developer command prompt" from visual studio tools,
Type it as devenv.exe /resetuserdata
Restart the machine, Open the Visual studio then It will ask you to choose the development settings from initial onwards, thereafter open any solution/project. You'll be amazed.
Hope, it might helps you :)
Deleted the .suo file in solution folder to solve the problem.
Sometimes i've found Intellisense to be slow. Hit the . and wait for a minute and see if it appears after a delay. If so, then I believe there may be a cache that can be deleted to get it to rescan.
I hit this today after the following sequence:
Added a new class to my project.
Closed Visual Studio, but accidentally selected No when it asked if I wanted to save changes.
Reopened Visual Studio, and found that it reopened the new file automatically but without my previous changes (as expected). However, IntelliSense was no longer working in the new file.
The problem was in addition to not saving changes to the new file, it didn't save changes to the project, so after reopening Visual Studio the file was not part of the project. The Show All Files command in Solution Explorer, or Add → Existing Item..., resolved the problem.
I had the file excluded from the project so i was not able to debug and have intellisense on that file.
Including the file back into the project solved my problem! :)
A new cause for this in the .net core era is having a project loaded for an unsupported .net core version. For instance if you loaded a project from GitHub that was set to use:
<PropertyGroup>
<TargetFramework>netcoreapp2.2</TargetFramework>
<AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
</PropertyGroup>
But you only have 2.1 installed or find yourself using Visual Studio 2017 then the compiler wont be able to find the SDK code and thus provide intellisense.
The solution in that case might be to right click on your project and select Edit MyProject.csproj from the context menu and change the target framework as necessary:
<PropertyGroup>
<TargetFramework>netcoreapp2.1</TargetFramework>
<AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
</PropertyGroup>
This assumes whatever project you loaded can actually be run under a lesser target framework.
I simply closed all pages of visual studio and reopened ..it worked.
Deleting the .vs folder in the solution solved my issue. You have to exit from Visual Studio and then delete the .vs folder and start Visual Studio again.
Closed all my VS windows
Started the Visual Studio Installer and clicked 'Modify'.
Under 'Individual components' > 'Code Tools' > Deselected NuGet package manager and re-selected it.
After modifying and restarting VS, IntelliSense was working correctly again.
Found my answer on https://developercommunity.visualstudio.com/content/problem/130597/unity-intellisense-not-working-after-creating-new-1.html
[Tools -> Options -> Text Editor -> All Languages -> CodeLens]
Check if check box "Enable CodeLens" is checked
I have just come to about this problem while installing one of the extensions and its file was deleted by my anti virus so I just disabled my anti virus and reinstalled visual studio. Suggestions are working properly without any changes made after installation.
At the bottommost right look at the blue line where Ln, Col, Spaces, UTF, CRLF,..... here the language is specified.
Check that your language and the language specified there are the same.
In my case, it was Django Python while I was trying to use HTML.
This may be due to the solution configuration changed to Release Mode instead of debug. Right click on solution -> Properties -> Configuration Properties -> Set Configuration To Debug if it is in Release.