输出txt文本

SaveFileDialog sfd = new SaveFileDialog();
sfd.Filter  = "文本文件 (*.txt)|*.txt|所有文件 (*.*)|*.*";
if(sfd.ShowDialog() == DialogResult.Cancel)
    return;
bool bFileExisted = System.IO.File.Exists(sfd.FileName);
System.IO.StreamWriter f_name = new System.IO.StreamWriter(sfd.FileName, bFileExisted, System.Text.Encoding.Default);
//打印表头
if(!bFileExisted)
    f_name.WriteLine ("SJJK0101~~销售单据传入");
for(i_row=1;i_row<=outBlock.blk_info [1].row;i_row++)
{
    outBlock.BlockNow = 2;
    f_name.WriteLine ("//单据{0}",i_row);    
    f_name.WriteLine ("{0}~~{1}~~{2}~~{3}~~{4}~~{5}~~{6}~~{7}~~{8}",outBlock.GetColVal(i_row,"invoice_num_10").ToString(),outBlock.GetColVal(i_row,"invoice_seq_num").ToString(),outBlock.GetColVal(i_row,"settle_user_name").ToString(),outBlock.GetColVal(i_row,"tax_num").ToString(),outBlock.GetColVal(i_row,"sett_user_addr_name").ToString(),outBlock.GetColVal(i_row,"account_num").ToString(),outBlock.GetColVal(i_row,"all_remark").ToString(),efCB_shenhe.Text.ToString().Trim(),efCB_kaipiao.Text.ToString().Trim());
    invoice_num = outBlock.GetColVal(i_row,"invoice_num_10").ToString();
    for(r_row=1;r_row<=outBlock.blk_info[2].row;r_row++)
    {
        outBlock.BlockNow = 3;
        if(outBlock.GetColVal(r_row,"invoice_num_10").ToString() == invoice_num)
        {
            f_name.WriteLine ("{0}~~{1}~~{2}~~{3}~~{4}~~{5}~~{6}~~{7}~~{8}~~{9}~~{10}",outBlock.GetColVal(r_row,"chinese_prod_abbr").ToString()+outBlock.GetColVal(r_row,"sg_sign").ToString().Trim(),"吨",outBlock.GetColVal(r_row,"stand").ToString(),outBlock.GetColVal(r_row,"weight_ready_tot").ToString(),outBlock.GetColVal(r_row,"good_amount").ToString(),outBlock.GetColVal(r_row,"tax_rate").ToString(),"1601",outBlock.GetColVal(r_row,"interest").ToString(),outBlock.GetColVal(r_row,"amount_tax").ToString(),0,0);
        }
    }
}
f_name.Close();
this.EFMsgInfo = "写入txt成功！";