private void ToExcelbtn_Click(object sender, EventArgs e)
{
try
{
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = "Excel files (*.xls)|*.xls";
saveFileDialog.FilterIndex = 0;
saveFileDialog.RestoreDirectory = true;
saveFileDialog.Title = "导出属性表为Excel";
if (saveFileDialog.ShowDialog(this) == DialogResult.OK)
{
Stream myStream;
myStream = saveFileDialog.OpenFile();
StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding(-0));
string str = "";
try
{
//写标题
for (int i = 1; i < gridView1.Columns.Count; i++)
{
if (i > 1)
{
str += "\t";