获取txt文本

string str;
string invoice_num_10;
string invoice_num_9;
double invoice_amount_9=0;
double invoice_tax_9=0;
int i;
if(openFileDialog1.ShowDialog()  == DialogResult.Cancel)
    return;
System.IO.StreamReader f_name = new System.IO.StreamReader(openFileDialog1.FileName,System.Text.Encoding.Default);
while((str = f_name.ReadLine()) != null)  //读取每一行的信息
{
    if(str.StartsWith("//"))
    {
        str = f_name.ReadLine();
        //int nRowCount = Convert.ToInt32(str[3]);
        str = str.Replace("~~", "~");
        string[] mychar = str.Split('~');
        int nRowCount = Convert.ToInt16(mychar[5]);
        invoice_num_9 = mychar[3]+mychar[4];
        invoice_num_10 = mychar[8];
        invoice_amount_9= Convert.ToDouble(mychar[9]);
        invoice_tax_9= Convert.ToDouble(mychar[11]);
        // MessageBox.Show(invoice_num_9);
    
        for(i=1;i<=efGrid1.EFRows -1;i++)  //循环Grid每一行，找到与读取invoice_num_10相同的行，并赋值
        {
            if(efGrid1.GetDataDisplay(i,"invoice_num_10").ToString().Trim() == invoice_num_10.Trim())
            {
                efGrid1[i,"check_option"] = true;
                efGrid1[i,"invoice_num_9"] = invoice_num_9;
                efGrid1[i,"invoice_amount_9"] =invoice_amount_9;
                efGrid1[i,"tax_amount_9"] =invoice_tax_9;
            }
        }
        for(int iRow=0; iRow<nRowCount; iRow++)
        {
            str = f_name.ReadLine();
        }
    }
}
f_name.Close();