export class PagedQueryModel {
  constructor(
    // ...
    public filterByColumn: string,
    public filterByValue: string,
  ) { }
}

  doFilter() {
    this.queryModel.page = 1;
    this.getPagedProductsList();
  }

  resetFilter() {
    this.queryModel.page = 1;
    this.queryModel.filterByColumn = "";
    this.queryModel.filterByValue = "";
    this.getPagedProductsList();
  }

<div class="panel panel-default">
  <div class="panel-body">
    <div class="form-group">
      <input type="text" [(ngModel)]="queryModel.filterByValue" placeholder="Search For ..."
        class="form-control" />
    </div>
    <div class="form-group">
      <select class="form-control" name="filterColumn" [(ngModel)]="queryModel.filterByColumn">
        <option value="">Filter by ...</option>
        <option *ngFor="let column of columns" [value]="column.propertyName">
          {{ column.title }}
        </option>
      </select>
    </div>
    <button class="btn btn-primary" type="button" (click)="doFilter()">Search</button>
    <button class="btn btn-default" type="button" (click)="resetFilter()">Reset</button>
  </div>
</div>

    public interface IPagedQueryModel
    {
    // ....
        string FilterByColumn { get; set; }
        string FilterByValue { get; set; }
    }

    public class ProductQueryViewModel : IPagedQueryModel
    {
        // ... other properties ...

// ...
        public string FilterByColumn { get; set; }
        public string FilterByValue { get; set; }
    }

    public static class IQueryableExtensions
    {
        public static IQueryable<T> ApplyFiltering<T>(
          this IQueryable<T> query,
          IPagedQueryModel model,
          IDictionary<string, Expression<Func<T, object>>> columnsMap)
        {
            if (string.IsNullOrWhiteSpace(model.FilterByValue) || !columnsMap.ContainsKey(model.FilterByColumn))
            {
                return query;
            }

            var func = columnsMap[model.FilterByColumn].Compile();
            return query.Where(x => func(x).ToString() == model.FilterByValue);
        }

var columnsMap = new Dictionary<string, Expression<Func<Product, object>>>()
            {
                ["productId"] = p => p.ProductId,
                ["productName"] = p => p.ProductName,
                ["isAvailable"] = p => p.IsAvailable,
                ["price"] = p => p.Price
            };
query = query.ApplyFiltering(queryModel, columnsMap);
query = query.ApplyOrdering(queryModel, columnsMap);

 Predefined type 'System.Void' is not defined or imported #1855

[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Located 2 MSBuild instance(s)
            1: Visual Studio Enterprise 2017 15.0.26228.4 - "e:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin"
            2: StandAlone 15.0 - "C:\Users\xyz\.vscode\extensions\ms-vscode.csharp-1.13.0\.omnisharp\msbuild\15.0\Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
        Registered MSBuild instance: Visual Studio Enterprise 2017 15.0.26228.4 - "e:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin"

VS Code ->  select View->Output -> select "OmniSharp Log"

<Target Name="PostcompileScript" AfterTargets="Build">
    <Exec Command="dotnet pack --no-build --configuration $(Configuration)" />
</Target>

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
    <Version>1.1.1</Version>
    <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
  </PropertyGroup>
</Project>

dotnet pack -c release

<Project>
  …
  <ItemGroup>
    <Content Include="README.txt">
      <Pack>true</Pack>
      <PackagePath>README.txt</PackagePath>
    </Content>
  </ItemGroup>
  …
</Project>

{  
  "apps": [
    {
 //...
      "assets": [
        "assets",
        "favicon.ico",
        "config.json"
      ],
 //...
}