This project is a port of Microsoft Reporting Services (Report Viewer) to .NET Core 3.1+. It is feature-complete and ready for production use, but keep in mind it is not officially supported by Microsoft.

For version history and recent fixes, see changelog.

With WinForms inclusion in .NET Core 3.1 and .NET 5 as a replacement for .NET Framework, it became feasible to port existing business desktop applications to .NET Core SDK to benefit from new C# and JIT features. Microsoft team stated on multiple occasions (dotnet/aspnetcore#1528, dotnet/aspnetcore#12666, dotnet/aspnetcore#22304, dotnet/docs#9607) that there are no plans to have official Reporting Services / ReportViewer package for .NET Core, which is a showstopper for applications using this technology for printing and reporting. The goal of this project is to provide transitional solution for such applications, until existing reports are reimplemented using more modern technology.

You should be able to replace references to Report Viewer in your WinForms project with ones provided in this repo and use Microsoft.Reporting.WinForms.ReportViewer as usual. See project ReportViewerCore.Sample.WinForms for a simplified example using local report processing and ReportViewerCore.Sample.WinFormsServer for remote processing using Reporting Services server.

For ASP.NET Core applications, add reference to Microsoft.Reporting.NETCore, which is based on WinForms version with stripped UI, and load/render report programmatically. See project ReportViewerCore.Console for an example or use following code as a starting point:

Stream reportDefinition; // your RDLC from file or resource
IEnumerable dataSource; // your datasource for the report

LocalReport report = new LocalReport();
report.LoadReportDefinition(reportDefinition);
report.DataSources.Add(new ReportDataSource("source", dataSource));
report.SetParameters(new[] { new ReportParameter("Parameter1", "Parameter value") });
byte[] pdf = report.Render("PDF");

For consuming Reporting Services (server-side) reports, use:

ServerReport report = new ServerReport();
report.ReportServerCredentials.NetworkCredentials = new NetworkCredential("login", "password", "DOMAIN");
report.ReportServerUrl = new Uri("http://localhost/ReportServer");
report.ReportPath = "/Invoice";
report.SetParameters(new[] { new ReportParameter("Date", DateTime.Now.Date.ToString()) });
byte[] pdf = report.Render("PDF");

or see project ReportViewerCore.WinFormsServer for more complete example.

There is no interactive, web-based report viewer provided in this project, but there are HTML4.0 and HTML5 rendering formats available. HTML5 format has been modified to also work without JavaScript. See ReportViewerCore.Sample.AspNetCore project for a simple demo.

Visual Studio 2019 (version 16.9 and similar) does not include Report Designer by default. There is an extension provided by Microsoft called "Microsoft RDLC Report Designer" you need to be able to open and modify your reports.

Even after installing the extension, new dataset wizard fails to show classes from your project and .NET Core projects don't have .datasource file support either. The workaround is to create and add .xsd file to your project with definitions of types you want to use in your reports. You can either create this file by hand or use the following snippet to produce one for all the classes you need:

var types = new[] { typeof(ReportItemClass1), typeof(ReportItemClass2), typeof(ReportItemClass3) };
var xri = new System.Xml.Serialization.XmlReflectionImporter();
var xss = new System.Xml.Serialization.XmlSchemas();
var xse = new System.Xml.Serialization.XmlSchemaExporter(xss);
foreach (var type in types)
{
    var xtm = xri.ImportTypeMapping(type);
    xse.ExportTypeMapping(xtm);
}
using var sw = new System.IO.StreamWriter("ReportItemSchemas.xsd", false, Encoding.UTF8);
for (int i = 0; i < xss.Count; i++)
{
    var xs = xss[i];
    xs.Id = "ReportItemSchemas";
    xs.Write(sw);
}

After including ReportItemSchemas.xsd file in your project, Report Designer should see a new datasource called ReportItemSchemas which you can use to add a dataset to your report.

Visual Studio 2022 does not support Report Designer as of 2022.01.

• RDLC file loading and compiling
• Local data sources
• Parameter passing
• PDF report rendering
• Microsoft Word rendering
• Microsoft Excel report rendering
• WinForms report preview
• Remote processing using Reporting Services
• Partial Linux / MacOS support
• MSChart control

• HTML4.0 / HTML5 / MHTML (works on Windows, Linux and Mac OS)
• PDF (Windows only)
• IMAGE (TIFF/EMF, Windows only)
• EXCEL (Microsoft Excel 97/2003, Windows only)
• EXCELOPENXML (Microsoft Excel Open XML - works on Windows, Linux and Mac OS)
• WORD (Microsoft Word 97/2003, Windows only)
• WORDOPENXML (Microsoft Word Open XML - works on Windows, Linux and Mac OS)

• Spatial SQL types. Those require Microsoft.SqlServer.Types package, which is available only in .NET Framework. Reports using SqlGeography won't load.
• Expression sandboxing and code security. Do not load and run reports from untrusted sources.
• Interactive web report preview. It is closely tied to WebForms and ASP.NET architecture and porting it to ASP.NET Core would involve rewriting significant portions of the codebase.
• IMAGE, PDF, DOC and XLS output format rendering in non-Windows systems due to GDI32 and OLE32 dependencies.
• WinForms control designer. To use ReportViewer in your WinForms project, add the control programmatically, as in ReportViewerCore.Sample.WinForms\ReportViewerForm.cs.
• Single .exe deployment. Roslyn needs to be able to reference .NET and ReportViewer assemblies at runtime. When compiled to a single file, those are unavailable and any non-trivial report won't compile.
• Map control. Not really tested, but included in project anyway.

If you get Version conflict detected for "Microsoft.CodeAnalysis.Common" error when adding this NuGet package, try first adding Microsoft.CodeAnalysis.CSharp.Workspaces 3.6.0 or Microsoft.CodeAnalysis.Common 3.6.0 (manually selecting version 3.6.0) package to your project. For .NET 5 use 3.8.0 version. For .NET 6 use 4.0.1.

Before reporting issue, please make sure that your problem occurs only when using this package, i.e. it doesn't happen on original Report Viewer. When filing an issue, include full exception stack trace and - where possible - provide relevant RDLC or a sample project.

Source code for this project comes from decompiling Report Viewer for WinForms, version 15.0.1404.0 using ILSpy. Original Reporting Services use external Visual Basic and System.CodeDom compilation, both of which are not available in .NET Core. Those have been replaced with Roslyn Visual Basic compiler. References to .NET Framework assemblies have been updated to NuGet packages where possible. References to unavailable assemblies, such as Microsoft.SqlServer.Types, have been removed along with functionalities that depend on them. Sources are intentionally left formatted as decompiled by ILSpy.

Project Microsoft.ReportViewer.WinForms is mostly one-to-one recompilation of original ReportViewer for WinForms. Project Microsoft.ReportViewer.NETCore is heavilly stripped down version suitable for web applications, web services and batch processing.

A precompiled package is available as ReportViewerCore.NETCore and ReportViewerCore.WinForms at nuget.org: ReportViewerCore.NETCore, ReportViewerCore.WinForms. Legal aspects of redistributing binary package are uncertain. Feel free to compile this project on your own. You'll need Visual Studio 2019 (Community version will do) and .NET Core SDK 3.1. Reference either Microsoft.ReportViewer.NETCore.dll or Microsoft.ReportViewer.WinForms.dll in your solution.

Reporting Services is a free Microsoft product. While decompiling and modifying it for compatibility reasons is legal in my local jurisdiction, redistributing modified version most likely is not. Use at your own risk.