Several methods of importing excel file data by C ＃

Method 1 ： utilize OleDb Direct connection Excel File to read data .

// obtain Excel route 
        string fileUrl = GetExcel(fuImportStudent);

        // Suitable for the old version xls file 
        const string cmdText = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=1;\"";
        // Suitable for new version xlsx file 
        //const string cmdText = "Provider=Microsoft.Ace.OleDb.12.0;Data Source={0};Extended Properties='Excel 12.0; HDR=Yes; IMEX=1'";

        System.Data.DataTable dt = null;
        // Establishing a connection 
        OleDbConnection connOleDb = new OleDbConnection(string.Format(cmdText, fileUrl));

        // Open the connection 
        if (connOleDb.State == ConnectionState.Broken || connOleDb.State == ConnectionState.Closed)
        {
            connOleDb.Open();
        }

        System.Data.DataTable schemaTable = connOleDb.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

        // obtain Excel One of the first Sheet name 
        string sheetName = schemaTable.Rows[0]["TABLE_NAME"].ToString().Trim();

        // Inquire about sheet Data in 
        string strSql = "select * from [" + sheetName + "]";
        OleDbDataAdapter da = new OleDbDataAdapter(strSql, connOleDb);
        DataSet ds = new DataSet();
        da.Fill(ds);
        // take Excel The data is translated into DataTable
        dt = ds.Tables[0];

        // Close the connection 
        connOleDb.Close();

        if (dt.Rows.Count > 0)
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                // Write to the database here 
                // get data ：dt.Rows[i][" Header name "].ToString()
            }
        }

If it is to use Microsoft.Jet.OLEDB.4.0 Connected , Need to set up IIS allow 32 Bit program ：

advantage ： Suitable for simple fixed format Excel form , As long as the header name is on the top , Don't worry about the order .

shortcoming ： If read directly MyXls Derived Excel There will be a problem that only the first column can be read （ Edit again or save as xls It can also solve this problem ）.

Method 2 ： utilize MyXls Read Excel data .

        // obtain Excel route 
        string fileUrl = GetExcel(fuImportContact);

        // Load the to be imported Excel
        XlsDocument xls = new XlsDocument(fileUrl);
        // get Excel Specify a work page in 
        Worksheet sheet = xls.Workbook.Worksheets[0];
        // Reading data   Cycle every sheet Every line of the work page , Before not reading 1 That's ok 
        for (int i = 2; i < sheet.Rows.Count; i++)
        {
            // Write to the database here 
            // get data ：sheet.Rows[ushort.Parse(i.ToString())].GetCell(1).Value.ToString()
        }

advantage ： Not server dependent , Can read MyXls Derived Excel file .

shortcoming ： Must follow Excel Get field data in the order of columns , Strict requirements for time format , The date in numeric format will appear , It needs to be changed . If the data of the column is empty, it may also cause that the column cannot be read , It's not stable .

Method 3 ： call Microsoft.Office.Interop.Excel Component read Excel data .

Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();

            Microsoft.Office.Interop.Excel.Workbook workbook;

            Microsoft.Office.Interop.Excel.Worksheet worksheet;

            object oMissing = System.Reflection.Missing.Value;// Quite a null

            workbook = excel.Workbooks.Open(filename, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing);

            worksheet = (Worksheet)workbook.Worksheets[1];

            //int rowCount = int.Parse(txtRow1.Text.Trim()) + 1;// worksheet.UsedRange.Rows.Count;

            int colCount = worksheet.UsedRange.Columns.Count;

            Microsoft.Office.Interop.Excel.Range range1;

            System.Data.DataTable dt = new System.Data.DataTable();

            for (int i = 0; i < colCount; i++)
            {
                range1 = worksheet.Range[worksheet.Cells[1, i + 1], worksheet.Cells[1, i + 1]];

                if (range1.Value2 != null)
                {
                    dt.Columns.Add(range1.Value2.ToString());
                }
            }

            for (int j = 1; j < rowCount; j++)
            {
                SetCount(j, label);

                DataRow dr = dt.NewRow();

                for (int i = 0; i < colCount; i++)
                {
                    range1 = worksheet.Range[worksheet.Cells[j + 1, i + 1], worksheet.Cells[j + 1, i + 1]];

                    if (range1.Value2 != null)
                    {
                        dr[i] = range1.Value2.ToString();
                    }
                }

                dt.Rows.Add(dr);

            }

            excel.Quit();

        if (dt.Rows.Count > 0)
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                // Write to the database here 
                // get data ：dt.Rows[i][" Header name "].ToString()
            }
        }

advantage ： Can read complex Excel Tabular data , Read columns regardless of order .

shortcoming ： Rely on server components , The server needs to be installed Excel Components .

If the time field becomes a number , Such as ：

It needs to be changed ：

private string ToDateTimeValue(string strNumber)
        {
            if (!string.IsNullOrWhiteSpace(strNumber))
            {
                Decimal tempValue;
                // First check   Is it a number ;
                if (Decimal.TryParse(strNumber, out tempValue))
                {
                    // Days , integer 
                    int day = Convert.ToInt32(Math.Truncate(tempValue));
                    // I don't know why .  If it's less than 32, Then subtract 1, Otherwise, decrease 2
                    // Date from 1900-01-01 Start accumulating  
                    // day = day < 32 ? day - 1 : day - 2;
                    DateTime dt = new DateTime(1900, 1, 1).AddDays(day < 32 ? (day - 1) : (day - 2));

                    // Hours : Subtract days , This number converts hours :(* 24) 
                    Decimal hourTemp = (tempValue - day) * 24;// Get hours 
                                                              // integer . Hours 
                    int hour = Convert.ToInt32(Math.Truncate(hourTemp));
                    // minute : Lose hours ,( * 60)
                    // Round here , Otherwise, the value will have 1 Minute error .
                    Decimal minuteTemp = Math.Round((hourTemp - hour) * 60, 2);// Get minutes 
                    int minute = Convert.ToInt32(Math.Truncate(minuteTemp));
                    // second : Lose minutes ,( * 60)
                    // Round here , Otherwise, the value will have 1 Second error .
                    Decimal secondTemp = Math.Round((minuteTemp - minute) * 60, 2);// Get seconds 
                    int second = Convert.ToInt32(Math.Truncate(secondTemp));

                    // Time format :00:00:00
                    string resultTimes = string.Format("{0}:{1}:{2}",
                            (hour < 10 ? ("0" + hour) : hour.ToString()),
                            (minute < 10 ? ("0" + minute) : minute.ToString()),
                            (second < 10 ? ("0" + second) : second.ToString()));

                    if (day > 0)
                        return string.Format("{0} {1}", dt.ToString("yyyy-MM-dd"), resultTimes);
                    else
                        return resultTimes;
                }
            }
            return string.Empty;
        }