winform简单代码导出Execl

private void DataToExecl()
        {
            if (this.dgTemp.Rows.Count > 0)//dgTemp为DataGridView控件
            {
                SaveFileDialog sfd = new SaveFileDialog();
                sfd.Title = "导出到Execl";
                sfd.DefaultExt = "xls";
                sfd.Filter = "Execl文件(*.xls)|.xls";
                sfd.FilterIndex = 0;
                sfd.RestoreDirectory = true;
                sfd.CreatePrompt = true;
                sfd.FileName = "XXXX.xls";//导出xls的文件名
                sfd.ShowDialog();
                if (sfd.FileName == "")
                {
                    return;
                }
                Stream stream = sfd.OpenFile();
                StreamWriter sw = new StreamWriter(stream, System.Text.Encoding.GetEncoding(-0));
                try
                {
                    string str1 = "";
                    for (int i = 0; i < this.dgTemp.ColumnCount; i++)
                    {
                        if (str1 != "")
                        {
                            str1 += "\t";
                        }
                        str1 += dgTemp.Columns[i].HeaderText;
                    }
                    sw.WriteLine(str1);

                    for (int j = 0; j < dgTemp.Rows.Count; j++)
                    {
                        string str2 = "";
                        for (int k = 0; k < dgTemp.Columns.Count; k++)
                        {
                            if (str2 != "")
                            {
                                str2 += "\t";
                            }
                            str2 += dgTemp.Rows[j].Cells[k].Value.ToString();
                        }
                        sw.WriteLine(str2);
                    }
                    sw.Close();
                    stream.Close();
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.ToString());
                }
                finally 
                {
                    sw.Close();
                    stream.Close();
                }
            }
        }