DataGridView数据导入到excel（C#）

Excel.Application app = new Excel.Application();
app.Visible = false;
Excel.Workbook wb = app.Workbooks.Add(true);
Excel.Worksheet ws = (Excel.Worksheet)wb.Worksheets.Add(Type.Missing, Type.Missing, Type.Missing,
Type.Missing);
DataTable dt = (DataTable)dgv.DataSource;
for (int i = 0; i ＜ dt.Columns.Count; i++)
{
ws.Cells[1, i + 1] = dt.Columns[i].ColumnName;
}
for (int j = 0; j ＜ dt.Rows.Count; j++)
{
for (int k = 0; k ＜ dt.Columns.Count; k++)
{
ws.Cells[j + 2, k + 1] = dt.Rows[j][k];
}
}
app.Visible = true;