导入导出功能，在调用ShowDialog时的错误，解决办法如下：
WinForm窗体的入口点：
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
private static void Main(String[] args)
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new LoginForm());
}
报错页面程序如下：
public string importPath=""; //全局变量，用于显示导入文件路劲
private void btnImport_Click(object sender, EventArgs e)
{
Thread importThread = new Thread(new ThreadStart(ImportDialog));
importThread.SetApartmentState(ApartmentState.STA); //重点
importThread.Start();
txtImportPath.Text = importPath;
}
public void ImportDialog()
{
OpenFileDialog open = new OpenFileDialog();
open.Filter = "Excel文件|*.xls;*.xlsx";
if (open.ShowDialog() == DialogResult.OK)
{
importPath = open.FileName;
ReadExcelToTable(importPath);
UpdateArea();
}
}