EPPlus - Read Excel Table
Asked Answered
T

8

44

Using EPPlus, I want to read an excel table, then store all the contents from each column into its corresponding List. I want it to recognize the table's heading and categorize the contents based on that.

For example, if my excel table is as below:

Id    Name     Gender
 1    John     Male
 2    Maria    Female
 3    Daniel   Unknown

I want the data to store in List<ExcelData> where

public class ExcelData
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string Gender { get; set; }
}

So that I can call out the contents using the heading name. For example, when I do this:

foreach (var data in ThatList)
{
     Console.WriteLine(data.Id + data.Name + data.Gender);
}

It will give me this output:

1JohnMale
2MariaFemale
3DanielUnknown

This is really all I got:

var package = new ExcelPackage(new FileInfo(@"C:\ExcelFile.xlsx"));
ExcelWorksheet sheet = package.Workbook.Worksheets[1];

var table = sheet.Tables.First();

table.Columns.Something //I guess I can use this to do what I want

Please help :( I have spent long hours searching for sample code regarding this so that I can learn from it but to no avail. I also understand ExcelToLinQ is managed to do that but it can't recognize table.

Toitoiboid answered 15/4, 2016 at 3:44 Comment(2)
So much promise but so disappointing. It is completely logical to define your data in an excel table then import that into a SQL Table via EPPlus. Apparently not.Hosey
Here is a generic function in C# to import data from an excel file to onject's' collection. writeafunction.com/…Mccants
I
37

There is no native but what if you use what I put in this post:

How to parse excel rows back to types using EPPlus

If you want to point it at a table only it will need to be modified. Something like this should do it:

public static IEnumerable<T> ConvertTableToObjects<T>(this ExcelTable table) where T : new()
{
    //DateTime Conversion
    var convertDateTime = new Func<double, DateTime>(excelDate =>
    {
        if (excelDate < 1)
            throw new ArgumentException("Excel dates cannot be smaller than 0.");

        var dateOfReference = new DateTime(1900, 1, 1);

        if (excelDate > 60d)
            excelDate = excelDate - 2;
        else
            excelDate = excelDate - 1;
        return dateOfReference.AddDays(excelDate);
    });

    //Get the properties of T
    var tprops = (new T())
        .GetType()
        .GetProperties()
        .ToList();

    //Get the cells based on the table address
    var start = table.Address.Start;
    var end = table.Address.End;
    var cells = new List<ExcelRangeBase>();

    //Have to use for loops insteadof worksheet.Cells to protect against empties
    for (var r = start.Row; r <= end.Row; r++)
        for (var c = start.Column; c <= end.Column; c++)
            cells.Add(table.WorkSheet.Cells[r, c]);

    var groups = cells
        .GroupBy(cell => cell.Start.Row)
        .ToList();

    //Assume the second row represents column data types (big assumption!)
    var types = groups
        .Skip(1)
        .First()
        .Select(rcell => rcell.Value.GetType())
        .ToList();

    //Assume first row has the column names
    var colnames = groups
        .First()
        .Select((hcell, idx) => new { Name = hcell.Value.ToString(), index = idx })
        .Where(o => tprops.Select(p => p.Name).Contains(o.Name))
        .ToList();

    //Everything after the header is data
    var rowvalues = groups
        .Skip(1) //Exclude header
        .Select(cg => cg.Select(c => c.Value).ToList());

    //Create the collection container
    var collection = rowvalues
        .Select(row =>
        {
            var tnew = new T();
            colnames.ForEach(colname =>
            {
                //This is the real wrinkle to using reflection - Excel stores all numbers as double including int
                var val = row[colname.index];
                var type = types[colname.index];
                var prop = tprops.First(p => p.Name == colname.Name);

                //If it is numeric it is a double since that is how excel stores all numbers
                if (type == typeof(double))
                {
                    if (!string.IsNullOrWhiteSpace(val?.ToString()))
                    {
                        //Unbox it
                        var unboxedVal = (double)val;

                        //FAR FROM A COMPLETE LIST!!!
                        if (prop.PropertyType == typeof(Int32))
                            prop.SetValue(tnew, (int)unboxedVal);
                        else if (prop.PropertyType == typeof(double))
                            prop.SetValue(tnew, unboxedVal);
                        else if (prop.PropertyType == typeof(DateTime))
                            prop.SetValue(tnew, convertDateTime(unboxedVal));
                        else
                            throw new NotImplementedException(String.Format("Type '{0}' not implemented yet!", prop.PropertyType.Name));
                    }
                }
                else
                {
                    //Its a string
                    prop.SetValue(tnew, val);
                }
            });

            return tnew;
        });


    //Send it back
    return collection;
}

Here is a test method:

[TestMethod]
public void Table_To_Object_Test()
{
    //Create a test file
    var fi = new FileInfo(@"c:\temp\Table_To_Object.xlsx");

    using (var package = new ExcelPackage(fi))
    {
        var workbook = package.Workbook;
        var worksheet = workbook.Worksheets.First();
        var ThatList = worksheet.Tables.First().ConvertTableToObjects<ExcelData>();
        foreach (var data in ThatList)
        {
            Console.WriteLine(data.Id + data.Name + data.Gender);
        }

        package.Save();
    }
}

Gave this in the console:

1JohnMale
2MariaFemale
3DanielUnknown

Just be careful if you Id field is an number or string in excel since the class is expecting a string.

Inerrant answered 15/4, 2016 at 12:13 Comment(6)
This is a very brittle solution since any empty cells will completely break this code.Purpose
In test method getting error as "Error 1 'OfficeOpenXml.Table.ExcelTable' does not contain a definition for 'ConvertTableToObjects' and no extension method 'ConvertTableToObjects' accepting a first argument of type 'OfficeOpenXml.Table.ExcelTable' could be found (are you missing a using directive or an assembly reference?)"Nard
@suresh the error is simply saying it can't find the extension method at all. Make sure you it is declared somewhere where the test can get to it.Inerrant
@Purpose You are right. I updated the code to better handle that. Anyone using this should still thoroughly test it. It is not 100% perfect (like most things on SO).Inerrant
Just be aware of the fact once there is a misspelling in file path or name, thera are no worksheets :-)Cathrin
@dinosaur What is the error? Maybe post as a question if you need to add alot of detail.Inerrant
N
49

Not sure why but none of the above solution work for me. So sharing what worked:

public void readXLS(string FilePath)
{
    FileInfo existingFile = new FileInfo(FilePath);
    using (ExcelPackage package = new ExcelPackage(existingFile))
    {
        //get the first worksheet in the workbook
        ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
        int colCount = worksheet.Dimension.End.Column;  //get Column Count
        int rowCount = worksheet.Dimension.End.Row;     //get row count
        for (int row = 1; row <= rowCount; row++)
        {
            for (int col = 1; col <= colCount; col++)
            {
                Console.WriteLine(" Row:" + row + " column:" + col + " Value:" + worksheet.Cells[row, col].Value?.ToString().Trim());
            }
        }
    }
}
Nard answered 22/8, 2018 at 9:23 Comment(4)
But how does this answer the OP's question? He was asking about taking a Table in Excel and converting into .NET objects - automagically with Generics. This traverses the rows/columns but would require manually mapping the values to properties.Inerrant
The line: ExcelWorksheet worksheet = package.Workbook.Worksheets[1]; is giving me exception: System.IndexOutOfRangeException: Worksheet position out of range.How is it possible? Can somebody help?Fractionize
@Noob, yes I did. But now it works fine. Thanks for trying to help me.Fractionize
+ Worksheet: begin Index at 0 + Row/Column: begin Index at 1 And note: EPPlus Version 4.x is free. From version 5 EPPlus changes the licence model using a dual license.Ephram
I
37

There is no native but what if you use what I put in this post:

How to parse excel rows back to types using EPPlus

If you want to point it at a table only it will need to be modified. Something like this should do it:

public static IEnumerable<T> ConvertTableToObjects<T>(this ExcelTable table) where T : new()
{
    //DateTime Conversion
    var convertDateTime = new Func<double, DateTime>(excelDate =>
    {
        if (excelDate < 1)
            throw new ArgumentException("Excel dates cannot be smaller than 0.");

        var dateOfReference = new DateTime(1900, 1, 1);

        if (excelDate > 60d)
            excelDate = excelDate - 2;
        else
            excelDate = excelDate - 1;
        return dateOfReference.AddDays(excelDate);
    });

    //Get the properties of T
    var tprops = (new T())
        .GetType()
        .GetProperties()
        .ToList();

    //Get the cells based on the table address
    var start = table.Address.Start;
    var end = table.Address.End;
    var cells = new List<ExcelRangeBase>();

    //Have to use for loops insteadof worksheet.Cells to protect against empties
    for (var r = start.Row; r <= end.Row; r++)
        for (var c = start.Column; c <= end.Column; c++)
            cells.Add(table.WorkSheet.Cells[r, c]);

    var groups = cells
        .GroupBy(cell => cell.Start.Row)
        .ToList();

    //Assume the second row represents column data types (big assumption!)
    var types = groups
        .Skip(1)
        .First()
        .Select(rcell => rcell.Value.GetType())
        .ToList();

    //Assume first row has the column names
    var colnames = groups
        .First()
        .Select((hcell, idx) => new { Name = hcell.Value.ToString(), index = idx })
        .Where(o => tprops.Select(p => p.Name).Contains(o.Name))
        .ToList();

    //Everything after the header is data
    var rowvalues = groups
        .Skip(1) //Exclude header
        .Select(cg => cg.Select(c => c.Value).ToList());

    //Create the collection container
    var collection = rowvalues
        .Select(row =>
        {
            var tnew = new T();
            colnames.ForEach(colname =>
            {
                //This is the real wrinkle to using reflection - Excel stores all numbers as double including int
                var val = row[colname.index];
                var type = types[colname.index];
                var prop = tprops.First(p => p.Name == colname.Name);

                //If it is numeric it is a double since that is how excel stores all numbers
                if (type == typeof(double))
                {
                    if (!string.IsNullOrWhiteSpace(val?.ToString()))
                    {
                        //Unbox it
                        var unboxedVal = (double)val;

                        //FAR FROM A COMPLETE LIST!!!
                        if (prop.PropertyType == typeof(Int32))
                            prop.SetValue(tnew, (int)unboxedVal);
                        else if (prop.PropertyType == typeof(double))
                            prop.SetValue(tnew, unboxedVal);
                        else if (prop.PropertyType == typeof(DateTime))
                            prop.SetValue(tnew, convertDateTime(unboxedVal));
                        else
                            throw new NotImplementedException(String.Format("Type '{0}' not implemented yet!", prop.PropertyType.Name));
                    }
                }
                else
                {
                    //Its a string
                    prop.SetValue(tnew, val);
                }
            });

            return tnew;
        });


    //Send it back
    return collection;
}

Here is a test method:

[TestMethod]
public void Table_To_Object_Test()
{
    //Create a test file
    var fi = new FileInfo(@"c:\temp\Table_To_Object.xlsx");

    using (var package = new ExcelPackage(fi))
    {
        var workbook = package.Workbook;
        var worksheet = workbook.Worksheets.First();
        var ThatList = worksheet.Tables.First().ConvertTableToObjects<ExcelData>();
        foreach (var data in ThatList)
        {
            Console.WriteLine(data.Id + data.Name + data.Gender);
        }

        package.Save();
    }
}

Gave this in the console:

1JohnMale
2MariaFemale
3DanielUnknown

Just be careful if you Id field is an number or string in excel since the class is expecting a string.

Inerrant answered 15/4, 2016 at 12:13 Comment(6)
This is a very brittle solution since any empty cells will completely break this code.Purpose
In test method getting error as "Error 1 'OfficeOpenXml.Table.ExcelTable' does not contain a definition for 'ConvertTableToObjects' and no extension method 'ConvertTableToObjects' accepting a first argument of type 'OfficeOpenXml.Table.ExcelTable' could be found (are you missing a using directive or an assembly reference?)"Nard
@suresh the error is simply saying it can't find the extension method at all. Make sure you it is declared somewhere where the test can get to it.Inerrant
@Purpose You are right. I updated the code to better handle that. Anyone using this should still thoroughly test it. It is not 100% perfect (like most things on SO).Inerrant
Just be aware of the fact once there is a misspelling in file path or name, thera are no worksheets :-)Cathrin
@dinosaur What is the error? Maybe post as a question if you need to add alot of detail.Inerrant
P
4

This is my working version. Note that the resolvers code is not shown but are a spin on my implementation which allows columns to be resolved even though they are named slightly differently in each worksheet.

public static IEnumerable<T> ToArray<T>(this ExcelWorksheet worksheet, List<PropertyNameResolver> resolvers) where T : new()
{

  // List of all the column names
  var header = worksheet.Cells.GroupBy(cell => cell.Start.Row).First();

  // Get the properties from the type your are populating
  var properties = typeof(T).GetProperties().ToList();


  var start = worksheet.Dimension.Start;
  var end = worksheet.Dimension.End;

  // Resulting list
  var list = new List<T>();

  // Iterate the rows starting at row 2 (ie start.Row + 1)
  for (int row = start.Row + 1; row <= end.Row; row++)
  {
    var instance = new T();
    for (int col = start.Column; col <= end.Column; col++)
    {
      object value = worksheet.Cells[row, col].Text;

      // Get the column name zero based (ie col -1)
      var column = (string)header.Skip(col - 1).First().Value;

      // Gets the corresponding property to set
      var property = properties.Property(resolvers, column);

      try
      {
        var propertyName = property.PropertyType.IsGenericType
          ? property.PropertyType.GetGenericArguments().First().FullName
          : property.PropertyType.FullName;


        // Implement setter code as needed. 
        switch (propertyName)
        {
          case "System.String":
            property.SetValue(instance, Convert.ToString(value));
            break;
          case "System.Int32":
            property.SetValue(instance, Convert.ToInt32(value));
            break;
          case "System.DateTime":
            if (DateTime.TryParse((string) value, out var date))
            {
              property.SetValue(instance, date);
            }
            property.SetValue(instance, FromExcelSerialDate(Convert.ToInt32(value)));
            break;
          case "System.Boolean":
            property.SetValue(instance, (int)value == 1);
            break;
        }
      }
      catch (Exception e)
      {
        // instance property is empty because there was a problem.
      }

    } 
    list.Add(instance);
  }
  return list;
}

// Utility function taken from the above post's inline function.
public static DateTime FromExcelSerialDate(int excelDate)
{
  if (excelDate < 1)
    throw new ArgumentException("Excel dates cannot be smaller than 0.");

  var dateOfReference = new DateTime(1900, 1, 1);

  if (excelDate > 60d)
    excelDate = excelDate - 2;
  else
    excelDate = excelDate - 1;
  return dateOfReference.AddDays(excelDate);
}
Purpose answered 8/5, 2018 at 3:58 Comment(1)
I know it is a little late on this. Although this seems to be working for me, there seems to be an issue converting a DateTime. If the value can be parsed as a DateTime, you set the property value, and then try to set it again using the FromExcelSerialDate function, which then throws an error. Although the property is still set the right value, is there any reason there isn't an else in there ??Natator
V
1

Below code will read excel data into a datatable, which is converted to list of datarows.

if (FileUpload1.HasFile)
{
    if (Path.GetExtension(FileUpload1.FileName) == ".xlsx")
    {
        Stream fs = FileUpload1.FileContent;
        ExcelPackage package = new ExcelPackage(fs);
        DataTable dt = new DataTable();
        dt= package.ToDataTable();
        List<DataRow> listOfRows = new List<DataRow>();
        listOfRows = dt.AsEnumerable().ToList();

    }
}
using OfficeOpenXml;
using System.Data;
using System.Linq;

 public static class ExcelPackageExtensions
    {
        public static DataTable ToDataTable(this ExcelPackage package)
        {
            ExcelWorksheet workSheet = package.Workbook.Worksheets.First();
            DataTable table = new DataTable();
            foreach (var firstRowCell in workSheet.Cells[1, 1, 1, workSheet.Dimension.End.Column])
            {
                table.Columns.Add(firstRowCell.Text);
            }

            for (var rowNumber = 2; rowNumber <= workSheet.Dimension.End.Row; rowNumber++)
            {
                var row = workSheet.Cells[rowNumber, 1, rowNumber, workSheet.Dimension.End.Column];
                var newRow = table.NewRow();
                foreach (var cell in row)
                {
                    newRow[cell.Start.Column - 1] = cell.Text;
                }
                table.Rows.Add(newRow);
            }
            return table;
        }

    }
Vinaigrette answered 13/6, 2016 at 16:48 Comment(3)
getting the error 'ExcelPackage' does not contain a definition for 'ToDataTable' and no extension method 'ToDataTable' accepting a first argument of type 'ExcelPackage' could be found (are you missing a using directive or an assembly reference?)Selangor
@FenilPatel, which Spreadsheet library are you using, Interrop or EPPlus?Fractionize
@noobprogrammer EPPLusVinaigrette
M
1

Yet another way to do it.

I used Ernie S solution but it didn't work if I had empty cells in the first data row (it wasn't able to guess the data type from it).
So instead of getting a data type from Excel table I get it from the T parameter class properties using reflection.

/// <summary>
///     Converts table to list of T objects
/// </summary>
/// <typeparam name="T">The type to return</typeparam>
/// <param name="table">Data source</param>
/// <returns>List of T objects</returns>
public static IEnumerable<T> ConvertToObjects<T>(this ExcelTable table) where T : new()
{
    ExcelCellAddress start = table.Address.Start;
    ExcelCellAddress end = table.Address.End;
    List<ExcelRange> cells = new();

    for (int r = start.Row; r <= end.Row; r++)
        for (int c = start.Column; c <= end.Column; c++)
            cells.Add(table.WorkSheet.Cells[r, c]);

    List<IGrouping<int, ExcelRange>> allRows = cells
        .GroupBy(cell => cell.Start.Row)
        .OrderBy(cell => cell.Key)
        .ToList();

    IEnumerable<PropertyInfo> typeProperties = typeof(T).GetProperties();

    IGrouping<int, ExcelRangeBase> header = allRows.First();

    Dictionary<PropertyInfo, int> columns = new();

    foreach (ExcelRangeBase col in header)
    {
        string propName = col.GetValue<string>();
        PropertyInfo propInfo = typeProperties.FirstOrDefault(x => x.Name.Equals(propName));
        if (propInfo != null)
        {
            columns.Add(propInfo, col.Start.Column);
        }                    
    }

    IEnumerable<IGrouping<int, ExcelRangeBase>> rows = allRows.Skip(1);

    List<T> objects = new();

    foreach (IGrouping<int, ExcelRangeBase> row in rows)
    {
        T obj = new();
        foreach (KeyValuePair<PropertyInfo, int> colInfo in columns)
        {
            ExcelRangeBase col = row.First(x => x.Start.Column == colInfo.Value);

            if (col.Value == null)
                continue;

            object value = Convert.ChangeType(col.Value, Nullable.GetUnderlyingType(colInfo.Key.PropertyType) ?? colInfo.Key.PropertyType);
            colInfo.Key.SetValue(obj, value);
        }
        objects.Add(obj);
    }

    return objects;
}
Margarine answered 4/12, 2021 at 21:27 Comment(0)
C
0

I have got an error on the first answer so I have changed some code line.

Please try my new code, it's working for me.

using OfficeOpenXml;
using OfficeOpenXml.Table;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

public static class ImportExcelReader
{
    public static List<T> ImportExcelToList<T>(this ExcelWorksheet worksheet) where T : new()
    {
        //DateTime Conversion
        Func<double, DateTime> convertDateTime = new Func<double, DateTime>(excelDate =>
        {
            if (excelDate < 1)
            {
                throw new ArgumentException("Excel dates cannot be smaller than 0.");
            }

            DateTime dateOfReference = new DateTime(1900, 1, 1);

            if (excelDate > 60d)
            {
                excelDate = excelDate - 2;
            }
            else
            {
                excelDate = excelDate - 1;
            }

            return dateOfReference.AddDays(excelDate);
        });

        ExcelTable table = null;

        if (worksheet.Tables.Any())
        {
            table = worksheet.Tables.FirstOrDefault();
        }
        else
        {
            table = worksheet.Tables.Add(worksheet.Dimension, "tbl" + ShortGuid.NewGuid().ToString());

            ExcelAddressBase newaddy = new ExcelAddressBase(table.Address.Start.Row, table.Address.Start.Column, table.Address.End.Row + 1, table.Address.End.Column);

            //Edit the raw XML by searching for all references to the old address
            table.TableXml.InnerXml = table.TableXml.InnerXml.Replace(table.Address.ToString(), newaddy.ToString());
        }

        //Get the cells based on the table address
        List<IGrouping<int, ExcelRangeBase>> groups = table.WorkSheet.Cells[table.Address.Start.Row, table.Address.Start.Column, table.Address.End.Row, table.Address.End.Column]
            .GroupBy(cell => cell.Start.Row)
            .ToList();

        //Assume the second row represents column data types (big assumption!)
        List<Type> types = groups.Skip(1).FirstOrDefault().Select(rcell => rcell.Value.GetType()).ToList();

        //Get the properties of T
        List<PropertyInfo> modelProperties = new T().GetType().GetProperties().ToList();

        //Assume first row has the column names
        var colnames = groups.FirstOrDefault()
            .Select((hcell, idx) => new
            {
                Name = hcell.Value.ToString(),
                index = idx
            })
            .Where(o => modelProperties.Select(p => p.Name).Contains(o.Name))
            .ToList();

        //Everything after the header is data
        List<List<object>> rowvalues = groups
            .Skip(1) //Exclude header
            .Select(cg => cg.Select(c => c.Value).ToList()).ToList();

        //Create the collection container
        List<T> collection = new List<T>();
        foreach (List<object> row in rowvalues)
        {
            T tnew = new T();
            foreach (var colname in colnames)
            {
                //This is the real wrinkle to using reflection - Excel stores all numbers as double including int
                object val = row[colname.index];
                Type type = types[colname.index];
                PropertyInfo prop = modelProperties.FirstOrDefault(p => p.Name == colname.Name);

                //If it is numeric it is a double since that is how excel stores all numbers
                if (type == typeof(double))
                {
                    //Unbox it
                    double unboxedVal = (double)val;

                    //FAR FROM A COMPLETE LIST!!!
                    if (prop.PropertyType == typeof(int))
                    {
                        prop.SetValue(tnew, (int)unboxedVal);
                    }
                    else if (prop.PropertyType == typeof(double))
                    {
                        prop.SetValue(tnew, unboxedVal);
                    }
                    else if (prop.PropertyType == typeof(DateTime))
                    {
                        prop.SetValue(tnew, convertDateTime(unboxedVal));
                    }
                    else if (prop.PropertyType == typeof(string))
                    {
                        prop.SetValue(tnew, val.ToString());
                    }
                    else
                    {
                        throw new NotImplementedException(string.Format("Type '{0}' not implemented yet!", prop.PropertyType.Name));
                    }
                }
                else
                {
                    //Its a string
                    prop.SetValue(tnew, val);
                }
            }
            collection.Add(tnew);
        }

        return collection;
    }
}

How to call this function? please view below code;

private List<FundraiserStudentListModel> GetStudentsFromExcel(HttpPostedFileBase file)
    {
        List<FundraiserStudentListModel> list = new List<FundraiserStudentListModel>();
        if (file != null)
        {
            try
            {
                using (ExcelPackage package = new ExcelPackage(file.InputStream))
                {
                    ExcelWorkbook workbook = package.Workbook;
                    if (workbook != null)
                    {
                        ExcelWorksheet worksheet = workbook.Worksheets.FirstOrDefault();
                        if (worksheet != null)
                        {
                            list = worksheet.ImportExcelToList<FundraiserStudentListModel>();
                        }
                    }
                }
            }
            catch (Exception err)
            {
                //save error log
            }
        }
        return list;
    }

FundraiserStudentListModel here:

 public class FundraiserStudentListModel
{
    public string Name { get; set; }
    public string Email { get; set; }
    public string Phone { get; set; }
}
Cutis answered 12/2, 2019 at 6:0 Comment(0)
S
0

Working solution with validate email,mobile number

 public class ExcelProcessing
        {
            public List<ExcelUserData> ReadExcel()
            {
                string path = Config.folderPath + @"\MemberUploadFormat.xlsx";
    
                using (var excelPack = new ExcelPackage())
                {
                    //Load excel stream
                    using (var stream = File.OpenRead(path))
                    {
                        excelPack.Load(stream);
                    }
    
                    //Lets Deal with first worksheet.(You may iterate here if dealing with multiple sheets)
                    var ws = excelPack.Workbook.Worksheets[0];
    
                    List<ExcelUserData> userList = new List<ExcelUserData>();
    
                    int colCount = ws.Dimension.End.Column;  //get Column Count
                    int rowCount = ws.Dimension.End.Row;
                       
                    for (int row = 2; row <= rowCount; row++) // start from to 2 omit header
                    {
                       
                        bool IsValid = true;
                        ExcelUserData _user = new ExcelUserData();
    
                        for (int col = 1; col <= colCount; col++)
                        {
                            if (col == 1)
                            {
                                _user.FirstName = ws.Cells[row, col].Value?.ToString().Trim();
                                if (string.IsNullOrEmpty(_user.FirstName))
                                {
                                    _user.ErrorMessage += "Enter FirstName <br/>";
                                    IsValid = false;
                                }
                            }
                            else if (col == 2)
                            {
                                _user.Email = ws.Cells[row, col].Value?.ToString().Trim();
    
                                if (string.IsNullOrEmpty(_user.Email))
                                {
                                    _user.ErrorMessage += "Enter Email <br/>";
                                    IsValid = false;
                                }
                                else if (!IsValidEmail(_user.Email))
                                {
                                    _user.ErrorMessage += "Invalid Email Address <br/>";
                                    IsValid = false;
                                }
                            }
                            else if (col ==3)
                            {
                                _user.MobileNo = ws.Cells[row, col].Value?.ToString().Trim();
    
                                if (string.IsNullOrEmpty(_user.MobileNo))
                                {
                                    _user.ErrorMessage += "Enter Mobile No <br/>";
                                    IsValid = false;
                                }
                                else if (_user.MobileNo.Length != 10)
                                {
                                    _user.ErrorMessage += "Invalid Mobile No <br/>";
                                    IsValid = false;
                                }
    
                            }
                            else if (col == 4)
                            {
                                _user.IsAdmin = ws.Cells[row, col].Value?.ToString().Trim();
    
                                if (string.IsNullOrEmpty(_user.IsAdmin))
                                {
                                    _user.IsAdmin = "0";
                                }
                            }
    
                            _user.IsValid = IsValid;
                        }
                        userList.Add(_user);
                    }
                    return userList;
                }
            }
            public static bool IsValidEmail(string email)
            {
                Regex regex = new Regex(@"^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$",
                 RegexOptions.CultureInvariant | RegexOptions.Singleline);
    
                return regex.IsMatch(email);
            }
        }
Satire answered 15/11, 2020 at 13:47 Comment(0)
T
0

With this code you won't get an error because a cell is null. it will also cast the data type according to the properties in your class!

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using OfficeOpenXml;

public static class ReadExcel
    {
        public static List<T> ReadExcelToList<T>(this ExcelWorksheet worksheet) where T : new()
        {
            List<T> collection = new List<T>();
            try
            {
                DataTable dt = new DataTable();
                foreach (var firstRowCell in new T().GetType().GetProperties().ToList())
                {
                    //Add table colums with properties of T
                    dt.Columns.Add(firstRowCell.Name);
                }
                for (int rowNum = 2; rowNum <= worksheet.Dimension.End.Row; rowNum++)
                {
                    var wsRow = worksheet.Cells[rowNum, 1, rowNum, worksheet.Dimension.End.Column];
                    DataRow row = dt.Rows.Add();
                    foreach (var cell in wsRow)
                    {
                        row[cell.Start.Column - 1] = cell.Text;
                    }
                }
                
                //Get the colums of table
                var columnNames = dt.Columns.Cast<DataColumn>().Select(c => c.ColumnName).ToList();
                
                //Get the properties of T
                List<PropertyInfo> properties = new T().GetType().GetProperties().ToList();

                collection = dt.AsEnumerable().Select(row =>
                {
                    T item = Activator.CreateInstance<T>();
                    foreach (var pro in properties)
                    {
                        if (columnNames.Contains(pro.Name) || columnNames.Contains(pro.Name.ToUpper()))
                        {
                            PropertyInfo pI = item.GetType().GetProperty(pro.Name);
                            pro.SetValue(item, (row[pro.Name] == DBNull.Value) ? null : Convert.ChangeType(row[pro.Name], (Nullable.GetUnderlyingType(pI.PropertyType) == null) ? pI.PropertyType : Type.GetType(pI.PropertyType.GenericTypeArguments[0].FullName)));
                        }
                    }
                    return item;
                }).ToList();

            }
            catch (Exception ex)
            {
                //Save error log
            }

            return collection;
        }
    }

How to call this function? please view below code;

public List<Users> GetStudentsFromExcel(HttpPostedFileBase file)
{
    List<Users> list = new List<Users>();
    if (file != null)
    {
        try
        {
            using (ExcelPackage package = new ExcelPackage(file.InputStream))
            {
                ExcelWorkbook workbook = package.Workbook;
                if (workbook != null)
                {
                    ExcelWorksheet worksheet = workbook.Worksheets.FirstOrDefault();
                    if (worksheet != null)
                    {
                        list = worksheet.ReadExcelToList<Users>();
                        //Your code
                    }
                }
            }
        }
        catch (Exception ex)
        {
            //Save error log
        }
    }
    return list;
}

public class Users
{
    public string Code { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
    public string Phone { get; set; }
    public string Address { get; set; }
    public DateTime CreatedAt { get; set; }
}

Hope to help someone!

Thrombokinase answered 7/9, 2021 at 14:27 Comment(0)

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