使用C#读取Excel文件会导致应用程序在显示结果之前冻结几秒钟？

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

public class ExcelReader
{
    private string filePath;
    private Thread thread;

    public ExcelReader(string filePath)
    {
        this.filePath = filePath;
    }

    public void ReadExcel()
    {
        thread = new Thread(() =>
        {
            Excel.Application excelApp = new Excel.Application();
            Excel.Workbook workbook = excelApp.Workbooks.Open(filePath);
            Excel.Worksheet worksheet = workbook.Sheets[1];

            // 读取Excel文件的操作

            workbook.Close();
            excelApp.Quit();
        });

        thread.Start();
    }

    public void WaitForCompletion()
    {
        thread.Join();
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        string filePath = "path/to/excel/file.xlsx";
        ExcelReader reader = new ExcelReader(filePath);
        reader.ReadExcel();

        // 执行其他操作

        reader.WaitForCompletion();

        // 显示结果
    }
}