Steps to Reproduce:

The debug console is output only. The input field you see is for inspecting the environment available at a given stack frame. In your launch config you can specify what console your program should use. Set the console property to externalTerminal. internalTerminal should work as well.
@weinand I think we should look for a way to make more explicit that the input field is inspection only.
@kieferrm thank you for your reply, below is my launch.json file and I didn't find a property called console, only externalConsole, when it's set to true the keyboard input can be accepted but a new console opened for the debugging, I cannot find internalTerminal configuration option. I tried to switch to the Integrated Terminal while the app waits for the keyboard input but it's the command line there waiting for a command.
Anyway I still wonder if I can debug the app within the Visual Studio Code UI while making Console.ReadLine() to work correctly.
{
"version": "0.2.0",
"configurations": [
{
"name": ".NET Core Launch (console)",
"type": "coreclr",
"request": "launch",
"preLaunchTask": "build",
"program": "${workspaceRoot}\\bin\\Debug\\netcoreapp1.1\\hwapp.dll",
"args": [],
"cwd": "${workspaceRoot}",
"externalConsole": false,
"stopAtEntry": false,
"internalConsoleOptions": "openOnFirstSessionStart"
},
{
"name": ".NET Core Attach",
"type": "coreclr",
"request": "attach",
"processId": "${command.pickProcess}"
}
]
}
If you can get a modified launch.json to solve my problem that will be great.
@LiangZugeng you are using the coreCLR debugger. I'll move this issue to the corresponding repository.
This issue was moved to OmniSharp/omnisharp-vscode#1053
Properties>Application>Output type Select into ComboBox "Console Application"
Most helpful comment
The debug console is output only. The input field you see is for inspecting the environment available at a given stack frame. In your launch config you can specify what console your program should use. Set the
consoleproperty toexternalTerminal.internalTerminalshould work as well.