c#大量二维数组数据导出到excel，先弹框选择文件地址，再将文件保存到指定地址，使用多个线程来分块写入数据，从而提高生成速度，代码示例

以下是一个基于C#的多线程写入Excel的示例代码，可以将大量二维数组数据导出到Excel中，同时弹出文件保存对话框让用户选择保存路径：

using System;
using System.Threading;
using System.Threading.Tasks;
using Excel = Microsoft.Office.Interop.Excel;
using Microsoft.Win32;

namespace ExcelExporter
{
    class Program
    {
        static void Main(string[] args)
        {
            // Show file dialog to let user select save path
            SaveFileDialog saveFileDialog = new SaveFileDialog();
            saveFileDialog.Filter = "Excel files (*.xlsx)|*.xlsx|All files (*.*)|*.*";
            if (saveFileDialog.ShowDialog() != true)
            {
                return;
            }
            string savePath = saveFileDialog.FileName;

            // Create a new Excel workbook and worksheet
            Excel.Application excel = new Excel.Application();
            Excel.Workbook workbook = excel.Workbooks.Add();
            Excel.Worksheet worksheet = workbook.Sheets[1];

            // Generate some sample data
            int rowCount = 10000; // Total row count
            int chunkSize = 100; // Rows to write per thread
            int threadCount = rowCount / chunkSize;
            int[][] data = new int[rowCount][];
            for (int i = 0; i < rowCount; i++)
            {
                data[i] = new int[] { i, i * 2, i * 3 };
            }

            // Write data to Excel using multiple threads
            Parallel.For(0, threadCount, i =>
            {
                int startRow = i * chunkSize + 1; // Excel row index starts from 1
                int endRow = Math.Min((i + 1) * chunkSize, rowCount);
                for (int j = startRow; j <= endRow; j++)
                {
                    for (int k = 0; k < data[j - 1].Length; k++)
                    {
                        worksheet.Cells[j, k + 1] = data[j - 1][k];
                    }
                }
            });

            // Save Excel file
            workbook.SaveAs(savePath);
            workbook.Close();
            excel.Quit();
            Console.WriteLine("Excel file saved!");
        }
    }
}

这个示例程序会弹出文件保存对话框让用户选择Excel文件保存路径，然后使用多个线程并行写入数据到Excel文件中，最终保存并关闭Excel文件。可以根据具体情况修改代码中的数据生成方式、行数、线程数和写入方式等参数。