Develop Reference

VSCode C# missing suggestions documentation tooltip while typing

I'm missing the suggestions documentation tooltip while doing C# in VSCode and having the C# Omnisharp extension installed.
What is this tooltip called? How can I turn this on?
Current behavior: https://i.stack.imgur.com/kD9E1.png
Wanted behaviour:https://i.stack.imgur.com/qdWYT.jpg
Note that I can see documentation, but only when I hover my mouse over it. Not while I'm typing: https://i.stack.imgur.com/PS1ft.png
C:\>code --list-extensions
77qingliu.sas-syntax
alexiv.vscode-angular2-files
Angular.ng-template
casualjim.theme-desertex
christian-kohler.path-intellisense
CoenraadS.bracket-pair-colorizer
Darfka.vbscript
eg2.tslint
esbenp.prettier-vscode
formulahendry.auto-rename-tag
infinity1207.angular2-switcher
ionceflorin.copy-current-file-path
jchannon.csharpextensions
jmrog.vscode-nuget-package-manager
johnpapa.Angular2
ms-vscode.csharp
msjsdiag.debugger-for-chrome
PKief.material-icon-theme
redhat.java
Shan.code-settings-sync
sohibe.java-generate-setters-getters
vscjava.vscode-java-debug
vscjava.vscode-java-pack
vscjava.vscode-java-test
vscjava.vscode-maven
vscodevim.vim

Finally found it. Tap ctrl + space twice! after the dot (.) while typing.
https://code.visualstudio.com/docs/editor/intellisense
"As provided by the language service, you can see quick info for each
method by either pressing Ctrl+Space or clicking the info icon. The
accompanying documentation for the method will now expand to the
side. The expanded documentation will stay so and will update as you
navigate the list.
You can close this by pressing Ctrl+Space again
or by clicking on the close icon."

Can I jump back from the definition to the previous reference?

When debugging in Visual Studio 2015, after jumping from a reference of an identity to its definition, can I jump back from the definition to the previous reference?
Thanks.

Yup. There is a "Navigate backwards" command that will do what you want.
You can see where it is for me and it is part of the "Standard" shortcut bar. It can also be found under the "View" menu or the keyboard shortcut is ctrl+-.

You could try Cntrl + -.
This would bring you to the last position of the cursor.
The original Answer is here
Did I get you right?
For more information on navigation by shortcuts this post is quite helpfull

Assuming that you have been doing things in sequence, you can Navigate Backwards
Keyboard Shortcut
Hitting Ctrl + - (Ctrl and minus at the same time)
Visual Studio Toolbar GUI
Alternatively, you can also do this by hitting the back button on the toolbar
Mouse Shortcut
Lastly, the "3rd" mouse button if you have one, usually on the left side. (The same mouse button that gets your browser to navigate backwards)

Is there a "Go To Variable Type Declaration" function for C# in Visual Studio 2015 or a free plugin which does it?

void MagicalFunction(MagicalType magic)
{
...
magic.Poof("something");
...
var foo = magic.GetFoo();
...
}
Pressing the hotkey on variable magic would navigate to definition of type MagicalType.
Pressing the hotkey on foo would go to definition of type Foo which is not directly visible here because of type-inference.
Resharper plugin has this functionality (called Go To Type of Symbol) , but is there a built-in alternative or a free-extension that does this?

Right click on the "var" keyword, select "Go to definition" from context menu, and it will take you to the type definition of the inferred type of the variable. I have some tools installed, like Productivity Power Tools which were mentioned, so not sure if this option is available through clean VS2015.
Edit:
You can also with cursor on the "var" keyword press Ctrl-F12 (Go to Implementation), if you prefer to use keyboard. Ref: https://www.youtube.com/watch?v=xWcQhF-1hxA

Sort of.
You could press F12 on "magic" to get to its definition, and then F12 again to get to its class.
Also, while you can't get anything meaningful by F12 on "foo" since it would just highlight the line you're already on, if you F12 from the "var" immediately prior to foo, it will jump you to the Foo class, even though that type is being inferred.

The function you are looking for is "Navigate To".
For some weird reason, the keyboard shortcut was removed from VS 2015. You can see this by going into the Edit menu. The option will be there but has no shortcut assigned to it.
You can fix this manually. The default was:
CTRL + ,
Go to Tools > Options > Environment > Keyboard, search for "Edit.NavigateTo" and reassign the shortcut. You can then place the cursor on the variable and hit the shortcut and a tiny window will overlay on the top right hand corner with possible candidates, one of them being the type definition.

Productivity Power Tools has a feature "Ctrl + Click Go To Definition
This extension gives the editor a web browser by adding clickable hyperlinks to symbols in your code as you hold down the Ctrl key."
https://visualstudiogallery.msdn.microsoft.com/d0d33361-18e2-46c0-8ff2-4adea1e34fef
it deosn't work in the first case but it works very well when you ctrl click "var" in the second case

Resharper - Disable 'help' when using "prop" shortcut in C#

I'm getting quite annoyed with a feature of Resharper that I just cannot find how to disable independently.
With Resharper turned off, whenever I type prop in VS2015 and press TAB, I get the following auto-generated code:
public int MyProperty { get; set; }
and I'm then able to switch between int and MyProperty repeatedly by pressing TAB again.
I'm also able to use autocomplete to fill in the variable type as I type.
For example, lets say I wanted to create a property called "test" of type "string", I would do the following:
type prop
press TAB to generate the property code template
type stri
press TAB to autocomplete the variable type with string
press TAB to move to the variable name placeholder
type test
press Return to finish
perfect.
However, with Resharper enabled, whilst steps 1,2 and 3 still work, it all goes to pot after that!
If I press TAB to try and autocomplete the variable type, the cursor simply moves over to the variable name, leaving the variable type as stri.
If I then press TAB (or even SHIFT+TAB) again to try and get back to it, it simply finishes the line.
To make things clearer, I've included two gifs demonstrating my problem.
This first one shows what happens with Resharper disabled:
Whilst this one illustrates the frustration I'm currently experiencing with Resharper enabled:

I understand this is an old(er) question and already has an answer; however, I wanted to provide a solution for future SO readers that would allow one to continue using Visual Studio's IntelliSense as opposed to Resharper's.
I had the same issue as the OP (original poster) and found the issue to be caused by a conflict with Resharper's Live Templates. With Resharper enabled, the resolution of prop after Tab + Tab, resolves Resharper's prop Live Template and not Visual Studio's prop snippet. You might have notice that in OP's 2nd screen cap (the one with Resharper enabled) that the resolution of prop has a datatype shown as TYPE instead of int. This is because Resharper's Live Template has set this parameter name to TYPE, while Visual Studio's snippet has the same parameter set to int by default. This is what lead me to look at Resharper's Live Templates for a resolution; lo and behold turning off the prop Live Template fixes the issue.
Go to Resharper's Template Explorer (Resharper -> Tools -> Templates Explorer) you will see there is a Live Template named prop. Simply clear the check box for the prop Live Template and Visual Studio's prop snippet resolution, and datatype resolution for that matter, will start working again.

It looks like you have an intellisense setting conflict.
Re-Enable Resharper and then change this setting:
Resharper->Options->IntelliSense->General
Change the selection from "Visual Studio" to "Resharper", hit Save and the desired behaviour should be yours.

I find those shortcuts still work without disabling anything however sometimes this functionality stops working.
Currently using R# 2018.2 with the default keyboard mappings set to IntelliJ IDEA scheme (as I also use java) and the shortcuts are all available, but when they stop working closing all tabs and reopening the tab you are working on normally fixes it.
No restart or reset is needed.

allowing to insert breakpoint in visual studio editor extension

Add Syntax Highlighting to IElisonBuffer
I follow this question and implement my visual studio editor extension.
I got everything working fine: syntax highlight, completion...but I cannot add breakpoint even thought the options was there in the right context menu (disabled)
Is there anything else I need to do to enable this feature for my editor?

Well, for the breakpoint to actually do anything, you'll need to implement a debugger (via the AD7 interfaces, etc.).
But to just get the actual breakpoint toggling working, all you need to do is implement the IVsLanguageDebugInfo interface (and optionally IVsLanguageDebugInfo2 and IVsLanguageDebugInfo3 too for more control). (I suggest you do so on the your language info object that's already implementing IVsLanguageInfo.) Don't forget to register your implementation so that VS knows about it.
ValidateBreakpointLocation() will be called when the user presses F9, etc., and in it you should set the breakpoint span to the appropriate bounds of the line (or portion of the line depending on your language, e.g. you might be in a lambda or want to highlight a statement except for any trailing comments on the line), then return VSConstants.S_OK.