在要WinForms 應用（.NET 8.0）中，顯示RDLC報表，就要使用ReportViewerCore.WinForms。原來的ReportViewer只能在.NET Framework框架下運行。

1.ReportViewerCore.WinForms 程序包說明

SQL Server Reporting Services ReportViewer WinForms control decompiled and recompiled for .NET Core. Based on ReportViewer 15.0.1404.0

2.主要程序ReportViewerForms.cs

using Microsoft.Reporting.WinForms;
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;namespace ReportViewerCore
{class ReportViewerForm : Form{private readonly ReportViewer reportViewer;public ReportViewerForm(){Text = "ReportViewerCore.WinForms示例(目標框架.NET 8.0)";//WindowState = FormWindowState.Maximized;this.Width = 1000;this.Height = 600;reportViewer = new ReportViewer();reportViewer.Dock = DockStyle.Fill;Controls.Add(reportViewer);// 設置打印布局模式,顯示物理頁面大小this.reportViewer.SetDisplayMode(Microsoft.Reporting.WinForms.DisplayMode.PrintLayout);// 縮放模式為百分比,以100%方式顯示this.reportViewer.ZoomMode = Microsoft.Reporting.WinForms.ZoomMode.Percent;this.reportViewer.ZoomPercent = 100;}protected override void OnLoad(EventArgs e){Report.Load(reportViewer.LocalReport);reportViewer.RefreshReport();base.OnLoad(e);}private void ReportViewerForm_Load(object sender, EventArgs e){}private void InitializeComponent(){SuspendLayout();// // ReportViewerForm// ClientSize = new System.Drawing.Size(784, 472);Name = "ReportViewerForm";StartPosition = FormStartPosition.CenterScreen;Load += ReportViewerForm_Load;ResumeLayout(false);}}
}

using Microsoft.Reporting.WinForms;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;namespace ReportViewerCore
{class Report{public static void Load(LocalReport report){var items = new[] { new ReportItem { Description = "Widget 6000", Price = 104.99m, Qty = 1 }, new ReportItem { Description = "Gizmo MAX", Price = 1.41m, Qty = 25 } };var parameters = new[] { new ReportParameter("Title", "Invoice 4/2020") };using var fs = new FileStream("Report.rdlc", FileMode.Open);report.LoadReportDefinition(fs);report.DataSources.Add(new ReportDataSource("Items", items));report.SetParameters(parameters);}}
}

3.實例窗口