//Write the relation between user pin and short message id(FileName:udata.dat) private void btnUDataWrite_Click(object sender, EventArgs e) { UDisk udisk = new UDisk(); int iCount = lvUData.Items.Count; byte[] byDataBuf = new byte[iCount * 4]; saveFileDialog1.Filter = "udata(*.dat)|*.dat"; saveFileDialog1.FileName = "udata.dat"; if (saveFileDialog1.ShowDialog() == DialogResult.OK) { int iDataBufIndex = 0; for (int i = 0; i < iCount; i++) { int iPIN = Convert.ToInt32(lvUData.Items[i].SubItems[0].Text.Trim()); int iSmsID = Convert.ToInt32(lvUData.Items[i].SubItems[1].Text.Trim()); byte[] byUDataInfo = null; udisk.SetUDataToDat(out byUDataInfo, iPIN, iSmsID); Array.Copy(byUDataInfo, 0, byDataBuf, iDataBufIndex, 4); iDataBufIndex += 4; } } File.WriteAllBytes(saveFileDialog1.FileName, byDataBuf); }