问题
I'm using the following code to convert an Excel to a datatable using EPPlus:
public DataTable ExcelToDataTable(string path)
{
var pck = new OfficeOpenXml.ExcelPackage();
pck.Load(File.OpenRead(path));
var ws = pck.Workbook.Worksheets.First();
DataTable tbl = new DataTable();
bool hasHeader = true;
foreach (var firstRowCell in ws.Cells[1, 1, 1, ws.Dimension.End.Column])
{
tbl.Columns.Add(hasHeader ? firstRowCell.Text : string.Format("Column {0}", firstRowCell.Start.Column));
}
var startRow = hasHeader ? 2 : 1;
for (var rowNum = startRow; rowNum <= ws.Dimension.End.Row; rowNum++)
{
var wsRow = ws.Cells[rowNum, 1, rowNum, ws.Dimension.End.Column];
var row = tbl.NewRow();
foreach (var cell in wsRow)
{
row[cell.Start.Column - 1] = cell.Text;
}
tbl.Rows.Add(row);
}
pck.Dispose();
return tbl;
}
It creates the Excel, however, when I try to open it, it gives me the message that it is locked for editing by another user and that I can only open it in Read-Only mode.
I thought using:
pck.Dispose();
would solve the issue, however I'm still getting the same error.
Also, when I try to delete the file, I get the message: The action can't be completed because the file is open in WebDev.WebServer40.EXE.
Any ideas how to resolve this? Thanks in advance. :)
回答1:
I see, that's what i've posted recently here(now corrected). It can be improved since the ExcelPackage and the FileStream(from File.OpenRead) are not disposed after using.
public static DataTable GetDataTableFromExcel(string path, bool hasHeader = true)
{
using (var pck = new OfficeOpenXml.ExcelPackage())
{
using (var stream = File.OpenRead(path))
{
pck.Load(stream);
}
var ws = pck.Workbook.Worksheets.First();
DataTable tbl = new DataTable();
foreach (var firstRowCell in ws.Cells[1, 1, 1, ws.Dimension.End.Column])
{
tbl.Columns.Add(hasHeader ? firstRowCell.Text : string.Format("Column {0}", firstRowCell.Start.Column));
}
var startRow = hasHeader ? 2 : 1;
for (int rowNum = startRow; rowNum <= ws.Dimension.End.Row; rowNum++)
{
var wsRow = ws.Cells[rowNum, 1, rowNum, ws.Dimension.End.Column];
DataRow row = tbl.Rows.Add();
foreach (var cell in wsRow)
{
row[cell.Start.Column - 1] = cell.Text;
}
}
return tbl;
}
}
回答2:
A extension version of Tim Schmelter's answer.
public static DataTable ToDataTable(this ExcelWorksheet ws, bool hasHeaderRow = true)
{
var tbl = new DataTable();
foreach (var firstRowCell in ws.Cells[1, 1, 1, ws.Dimension.End.Column])
tbl.Columns.Add(hasHeaderRow ?
firstRowCell.Text : string.Format("Column {0}", firstRowCell.Start.Column));
var startRow = hasHeaderRow ? 2 : 1;
for (var rowNum = startRow; rowNum <= ws.Dimension.End.Row; rowNum++)
{
var wsRow = ws.Cells[rowNum, 1, rowNum, ws.Dimension.End.Column];
var row = tbl.NewRow();
foreach (var cell in wsRow) row[cell.Start.Column - 1] = cell.Text;
tbl.Rows.Add(row);
}
return tbl;
}
回答3:
I've created a method that converts an Excel file to a DataTable using EPPlus, and tried to maintain Type Safety. Also duplicate column names are handled and with a boolean you can tell the method wether the sheet has a row with headers. I've created it for a complex import process that has several steps after uploading that requires user input before committing to the database.
private DataTable ExcelToDataTable(byte[] excelDocumentAsBytes, bool hasHeaderRow)
{
DataTable dt = new DataTable();
string errorMessages = "";
//create a new Excel package in a memorystream
using (MemoryStream stream = new MemoryStream(excelDocumentAsBytes))
using (ExcelPackage excelPackage = new ExcelPackage(stream))
{
ExcelWorksheet worksheet = excelPackage.Workbook.Worksheets[1];
//check if the worksheet is completely empty
if (worksheet.Dimension == null)
{
return dt;
}
//add the columns to the datatable
for (int j = worksheet.Dimension.Start.Column; j <= worksheet.Dimension.End.Column; j++)
{
string columnName = "Column " + j;
var excelCell = worksheet.Cells[1, j].Value;
if (excelCell != null)
{
var excelCellDataType = excelCell;
//if there is a headerrow, set the next cell for the datatype and set the column name
if (hasHeaderRow == true)
{
excelCellDataType = worksheet.Cells[2, j].Value;
columnName = excelCell.ToString();
//check if the column name already exists in the datatable, if so make a unique name
if (dt.Columns.Contains(columnName) == true)
{
columnName = columnName + "_" + j;
}
}
//try to determine the datatype for the column (by looking at the next column if there is a header row)
if (excelCellDataType is DateTime)
{
dt.Columns.Add(columnName, typeof(DateTime));
}
else if (excelCellDataType is Boolean)
{
dt.Columns.Add(columnName, typeof(Boolean));
}
else if (excelCellDataType is Double)
{
//determine if the value is a decimal or int by looking for a decimal separator
//not the cleanest of solutions but it works since excel always gives a double
if (excelCellDataType.ToString().Contains(".") || excelCellDataType.ToString().Contains(","))
{
dt.Columns.Add(columnName, typeof(Decimal));
}
else
{
dt.Columns.Add(columnName, typeof(Int64));
}
}
else
{
dt.Columns.Add(columnName, typeof(String));
}
}
else
{
dt.Columns.Add(columnName, typeof(String));
}
}
//start adding data the datatable here by looping all rows and columns
for (int i = worksheet.Dimension.Start.Row + Convert.ToInt32(hasHeaderRow); i <= worksheet.Dimension.End.Row; i++)
{
//create a new datatable row
DataRow row = dt.NewRow();
//loop all columns
for (int j = worksheet.Dimension.Start.Column; j <= worksheet.Dimension.End.Column; j++)
{
var excelCell = worksheet.Cells[i, j].Value;
//add cell value to the datatable
if (excelCell != null)
{
try
{
row[j - 1] = excelCell;
}
catch
{
errorMessages += "Row " + (i - 1) + ", Column " + j + ". Invalid " + dt.Columns[j - 1].DataType.ToString().Replace("System.", "") + " value: " + excelCell.ToString() + "<br>";
}
}
}
//add the new row to the datatable
dt.Rows.Add(row);
}
}
//show error messages if needed
Label1.Text = errorMessages;
return dt;
}
The webforms button click for demo purposes.
protected void Button1_Click(object sender, EventArgs e)
{
if (FileUpload1.HasFile)
{
DataTable dt = ExcelToDataTable(FileUpload1.FileBytes, CheckBox1.Checked);
GridView1.DataSource = dt;
GridView1.DataBind();
}
}
回答4:
This is an improvement to the generic one above. Use is if you have a class with the following properties, "Name", "Surname", "Telephone", "Fax" and you have a excel sheet with the first row with the same names, it will load the excel rows into a class object and pop it into a List
public static List<T> GetClassFromExcel<T>(string path, int fromRow, int fromColumn, int toRow = 0, int toColumn = 0)
{
if (toColumn != 0 && toColumn < fromColumn) throw new Exception("toColumn can not be less than fromColumn");
if (toRow != 0 && toRow < fromRow) throw new Exception("toRow can not be less than fromRow");
List<T> retList = new List<T>();
using (var pck = new ExcelPackage())
{
using (var stream = File.OpenRead(path))
{
pck.Load(stream);
}
//Retrieve first Worksheet
var ws = pck.Workbook.Worksheets.First();
//If the to column is empty or 0, then make the tocolumn to the count of the properties
//Of the class object inserted
toColumn = toColumn == 0 ? typeof(T).GetProperties().Count() : toColumn;
//Read the first Row for the column names and place into a list so that
//it can be used as reference to properties
Dictionary<string, int> columnNames = new Dictionary<string, int>();
// wsRow = ws.Row(0);
var colPosition = 0;
foreach (var cell in ws.Cells[1, 1, 1, toColumn == 0 ? ws.Dimension.Columns : toColumn])
{
columnNames.Add(cell.Value.ToString(), colPosition);
colPosition++;
}
//create a instance of T
T objT = Activator.CreateInstance<T>();
//Retrieve the type of T
Type myType = typeof(T);
//Get all the properties associated with T
PropertyInfo[] myProp = myType.GetProperties();
//Loop through the rows of the excel sheet
for (var rowNum = fromRow; rowNum <= (toRow == 0? ws.Dimension.End.Row : toRow); rowNum++)
{
var wsRow = ws.Cells[rowNum, fromColumn, rowNum, ws.Cells.Count()];
foreach (var propertyInfo in myProp)
{
if (columnNames.ContainsKey(propertyInfo.Name))
{
int position = 0;
columnNames.TryGetValue(propertyInfo.Name, out position);
//int position = columnNames.IndexOf(propertyInfo.Name);
//To prevent an exception cast the value to the type of the property.
propertyInfo.SetValue(objT, Convert.ChangeType(wsRow[rowNum, position + 1].Value, propertyInfo.PropertyType));
}
}
retList.Add(objT);
}
}
return retList;
}
now you can use the list as a databinding source if you need... A give from me to you... :) Daniel C. Vrey
Updated it for toColumn to work and added toRow and followed Andreas suggestions. Thumbs up for Andreas
回答5:
VDWWD's answer above works great to keep type safety, and I built upon it with some improvements.
- Method reads from a file directly.
- Column type detection by using all rows and not just one value. Column type is set to String if more than type is found in the column.
- Error Messages returned in a list of strings.
Here is the updated version:
public static DataTable ExcelToDataTable(string path, ref List<string> errorList, bool hasHeaderRow = true )
{
DataTable dt = new DataTable();
errorList = new List<string>();
//create a new Excel package
using (ExcelPackage excelPackage = new ExcelPackage())
{
using (var stream = File.OpenRead(path))
{
excelPackage.Load(stream);
}
ExcelWorksheet worksheet = excelPackage.Workbook.Worksheets[1];
//check if the worksheet is completely empty
if (worksheet.Dimension == null)
{
return dt;
}
//add the columns to the datatable
for (int j = worksheet.Dimension.Start.Column; j <= worksheet.Dimension.End.Column; j++)
{
string columnName = "Column " + j;
//Build hashset with all types in the row
var columnTypes = new HashSet<Type>();
for (int i = worksheet.Dimension.Start.Row + Convert.ToInt32(hasHeaderRow); i <= worksheet.Dimension.End.Row; i++)
{
//Only add type if cell value not empty
if (worksheet.Cells[i, j].Value != null)
{
columnTypes.Add(worksheet.Cells[i, j].Value.GetType());
}
}
var excelCell = worksheet.Cells[1, j].Value;
if (excelCell != null)
{
Type excelCellDataType = null;
//if there is a headerrow, set the next cell for the datatype and set the column name
if (hasHeaderRow == true)
{
columnName = excelCell.ToString();
//check if the column name already exists in the datatable, if so make a unique name
if (dt.Columns.Contains(columnName) == true)
{
columnName = columnName + "_" + j;
}
}
//Select input type for the column
if (columnTypes.Count == 1)
{
excelCellDataType = columnTypes.First();
}
else
{
excelCellDataType = typeof(string);
}
//try to determine the datatype for the column (by looking at the next column if there is a header row)
if (excelCellDataType == typeof(DateTime))
{
dt.Columns.Add(columnName, typeof(DateTime));
}
else if (excelCellDataType == typeof(Boolean))
{
dt.Columns.Add(columnName, typeof(Boolean));
}
else if (excelCellDataType == typeof(Double))
{
//determine if the value is a decimal or int by looking for a decimal separator
//not the cleanest of solutions but it works since excel always gives a double
if (excelCellDataType.ToString().Contains(".") || excelCellDataType.ToString().Contains(","))
{
dt.Columns.Add(columnName, typeof(Decimal));
}
else
{
dt.Columns.Add(columnName, typeof(Int64));
}
}
else
{
dt.Columns.Add(columnName, typeof(String));
}
}
else
{
dt.Columns.Add(columnName, typeof(String));
}
}
//start adding data the datatable here by looping all rows and columns
for (int i = worksheet.Dimension.Start.Row + Convert.ToInt32(hasHeaderRow); i <= worksheet.Dimension.End.Row; i++)
{
//create a new datatable row
DataRow row = dt.NewRow();
//loop all columns
for (int j = worksheet.Dimension.Start.Column; j <= worksheet.Dimension.End.Column; j++)
{
var excelCell = worksheet.Cells[i, j].Value;
//add cell value to the datatable
if (excelCell != null)
{
try
{
row[j - 1] = excelCell;
}
catch
{
errorList.Add("Row " + (i - 1) + ", Column " + j + ". Invalid " + dt.Columns[j - 1].DataType.ToString().Replace("System.", "") + " value: " + excelCell.ToString() );
}
}
}
//add the new row to the datatable
dt.Rows.Add(row);
}
}
return dt;
}
回答6:
public static List<T> GetClassFromExcel<T>(string path, int fromRow, int fromColumn, int toRow = 0, int toColumn = 0) where T: class, new()
{
if (toColumn != 0 && toColumn < fromColumn) throw new Exception("toColumn can not be less than fromColumn");
if (toRow != 0 && toRow < fromRow) throw new Exception("toRow can not be less than fromRow");
List<T> retList = new List<T>();
using (var pck = new ExcelPackage())
{
using (var stream = File.OpenRead(path))
{
pck.Load(stream);
}
//Retrieve first Worksheet
var ws = pck.Workbook.Worksheets.First();
toColumn = toColumn == 0 ? typeof(T).GetProperties().Count() : toColumn; //If the to column is empty or 0, then make the tocolumn to the count of the properties Of the class object inserted
//Read the first Row for the column names and place into a list so that
//it can be used as reference to properties
Dictionary<string, int> columnNames = new Dictionary<string, int>();
// wsRow = ws.Row(0);
var colPosition = 0;
foreach (var cell in ws.Cells[1, 1, 1, toColumn == 0 ? ws.Dimension.Columns : toColumn])
{
columnNames.Add(cell.Value.ToString(), colPosition);
colPosition++;
}
//Retrieve the type of T
Type myType = typeof(T);
//Get all the properties associated with T
PropertyInfo[] myProp = myType.GetProperties();
//Loop through the rows of the excel sheet
for (var rowNum = fromRow + 1; rowNum <= (toRow == 0 ? ws.Dimension.End.Row : toRow); rowNum++) // fromRow + 1 to read from next row after columnheader
{
//create a instance of T
//T objT = Activator.CreateInstance<T>();
T objT = new T();
// var wsRow = ws.Cells[rowNum, fromColumn, rowNum, ws.Cells.Count()]; //ws.Cells.Count() causing out of range error hence using ws.Dimension.Columns to get last column index
var wsRow = ws.Cells[rowNum, fromColumn, rowNum, ws.Dimension.Columns];
foreach (var propertyInfo in myProp)
{
var attribute = propertyInfo.GetCustomAttributes(typeof(DisplayNameAttribute), true).Cast<DisplayNameAttribute>().SingleOrDefault();
string displayName = attribute != null && !string.IsNullOrEmpty(attribute.DisplayName) ? attribute.DisplayName : propertyInfo.Name; // If DisplayName annotation not used then get property name itself
if (columnNames.ContainsKey(displayName))
{
int position = 0;
columnNames.TryGetValue(displayName, out position);
////int position = columnNames.IndexOf(propertyInfo.Name);
////To prevent an exception cast the value to the type of the property.
propertyInfo.SetValue(objT, Convert.ChangeType(wsRow[rowNum, position + 1].Value, propertyInfo.PropertyType));
}
}
retList.Add(objT);
}
}
return retList;
}
//IMPLEMENTATION DONE BY PLACING Code IT IN SEPARATE Helpers.CS file and
//Consuming it in this manner
List<CustomerExcelModel> records =
Helpers.GetClassFromExcel<CustomerExcelModel>(filelocation, 1, 1);
Thanks a lot to the user who Submitted code and Andreas for suggestion Here are the Following changes done, i am new to generics so forgive and correct me for any mistakes please find modified code below it might help someone
- Added Display Annotation entity model to map with the Excel Column name so that Column Name with spaces can also be handled.
- had issue "T objT " as it was outside of for loop and hence caused
same value repeatedly inserted into List fixed it by
instantiating inside loop i.e using "new T()" - Fixed Column out of range error by using "ws.Dimension.Columns" to get Column count , instead of ws.Cells.Count() as it caused out range column error
- for looping through row data added +1 to it ,as RowNum=1 was reading header name also so done minor change of "rowNum = fromRow + 1"
回答7:
public static List<T> getClassFromExcel<T>(string path, int fromRow, int fromColumn, int toColumn = 0) where T : class
{
using (var pck = new OfficeOpenXml.ExcelPackage())
{
List<T> retList = new List<T>();
using (var stream = File.OpenRead(path))
{
pck.Load(stream);
}
var ws = pck.Workbook.Worksheets.First();
toColumn = toColumn == 0 ? typeof(T).GetProperties().Count() : toColumn;
for (var rowNum = fromRow; rowNum <= ws.Dimension.End.Row; rowNum++)
{
T objT = Activator.CreateInstance<T>();
Type myType = typeof(T);
PropertyInfo[] myProp = myType.GetProperties();
var wsRow = ws.Cells[rowNum, fromColumn, rowNum, toColumn];
for (int i = 0; i < myProp.Count(); i++)
{
myProp[i].SetValue(objT, wsRow[rowNum, fromColumn + i].Text);
}
retList.Add(objT);
}
return retList;
}
}
回答8:
Here I am sharing how you can read the excel. You can modify it to store each date in datatables.
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++)
{
//You can update code here to add each cell value to DataTable.
Console.WriteLine(" Row:" + row + " column:" + col + " Value:" + worksheet.Cells[row, col].Value.ToString().Trim());
}
}
}
}
Reff: http://sforsuresh.in/read-data-excel-sheet-insert-database-table-c/
回答9:
Use below code if you want to read data of each worksheet from excel, as well if worksheet contain date format data for particular column.
public static DataSet ReadExcelFileToDataSet2(string filePath, bool isFirstRowHeader=true)
{
DataSet result = new DataSet();
Excel.ExcelPackage xlsPackage = new Excel.ExcelPackage(new FileInfo(filePath)); //using Excel = OfficeOpenXml; <--EPPLUS
Excel.ExcelWorkbook workBook = xlsPackage.Workbook;
try
{
for (int count = 1; count <= workBook.Worksheets.Count; count++)
{
Excel.ExcelWorksheet wsworkSheet = workBook.Worksheets[count];
if (wsworkSheet.Name.ToLower() == "sheetName")
{
wsworkSheet.Column(4).Style.Numberformat.Format = "MM-dd-yyyy"; // set column value to read as Date Type or numberformat
}
DataTable tbl = new DataTable();
// wsworkSheet.Dimension - (It will return cell dimesion like A1:N7 , means returning the worksheet dimesions.)
// wsworkSheet.Dimension.End.Address - (It will return right bottom cell like N7)
// wsworkSheet.Dimension.End.Columns - (It will return count from A1 to N7 like here 14)
foreach (var firstRowCell in wsworkSheet.Cells[1, 1, 1, wsworkSheet.Dimension.End.Column]) //.Cells[Row start, Column Start, Row end, Column End]
{
var colName = "";
colName = firstRowCell.Text;
tbl.Columns.Add(isFirstRowHeader ? colName : string.Format("Column {0}", firstRowCell.Start.Column)); //Geth the Column index (index starting with 1) from the left top.
}
var startRow = isFirstRowHeader ? 2 : 1;
for (int rowNum = startRow; rowNum <= wsworkSheet.Dimension.End.Row; rowNum++)
{
var wsRow = wsworkSheet.Cells[rowNum, 1, rowNum, wsworkSheet.Dimension.End.Column]; // wsworkSheet.Cells[Row start, Column Start, Row end, Column End]
DataRow row = tbl.Rows.Add();
foreach (var cell in wsRow)
{
row[cell.Start.Column - 1] = cell.Text;
}
}
tbl.TableName = wsworkSheet.Name;
result.Tables.Add(tbl);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
return result;
}
来源：https://stackoverflow.com/questions/13396604/excel-to-datatable-using-epplus-excel-locked-for-editing