例如：

private void Import() {

Excel.Application myExcel  = new Excel.Application();

myExcel.Workbooks.Add(openFileDialog1.FileName);

//........

//读取EXCEL文件，导入到数据库.

//清除excel垃圾进程

myExcel.Workbooks.Close();

myExcel.Quit();

System.Runtime.InteropServices.Marshal.ReleaseComObject(myExcel);

myExcel = null;

}

private void ExcelImport() {

Import();

GC.Collect();

}

//以下按button1按钮,使用多线程读取EXCEL文件，导入到数据库．

private void button1_Click(object sender, System.EventArgs e) {

if(openFileDialog1.ShowDialog() == DialogResult.OK) {

System.Threading.Thread t=new System.Threading.Thread(new System.Threading.ThreadStart(ExcelImport));

t.Start();

}

}