36

我正在使用以下代码使用 EPPlus 将 Excel 转换为数据表:

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;
}

它会创建 Excel,但是,当我尝试打开它时,它会提示我它已被其他用户锁定以供编辑,并且我只能在只读模式下打开它。

我想使用:

pck.Dispose();

可以解决问题,但是我仍然遇到同样的错误。

此外,当我尝试删除文件时,我收到消息:无法完成操作,因为文件已在 WebDev.WebServer40.EXE 中打开。

任何想法如何解决这个问题?提前致谢。:)

4

9 回答 9

105

我明白了,这就是我最近在这里发布的内容(现已更正)。由于使用后不处理theExcelPackage和 the FileStream(from ) ,因此可以改进它。File.OpenRead

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;
    }
}
于 2012-11-15T11:39:27.597 回答
12

Tim Schmelter 答案的扩展版本。

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;
}
于 2014-11-20T04:41:58.877 回答
6

我创建了一种使用 EPPlus 将 Excel 文件转换为 DataTable 的方法,并尝试维护类型安全。还会处理重复的列名,并且使用布尔值可以告诉方法工作表是否有带标题的行。我为一个复杂的导入过程创建了它,该过程在上传后有几个步骤,在提交到数据库之前需要用户输入。

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;
}

用于演示目的的网络表单按钮单击。

protected void Button1_Click(object sender, EventArgs e)
{
    if (FileUpload1.HasFile)
    {
        DataTable dt = ExcelToDataTable(FileUpload1.FileBytes, CheckBox1.Checked);

        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
}
于 2017-06-02T14:01:00.800 回答
5

这是对上述通用版本的改进。使用的是,如果您有一个具有以下属性的类,“姓名”、“姓氏”、“电话”、“传真”,并且您有一个具有相同名称的第一行的 excel 表,它会将 excel 行加载到类对象并将其弹出到列表中

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;
    }

现在,如果需要,您可以将列表用作数据绑定源...我给您的礼物... :) Daniel C. Vrey

更新它以使 toColumn 工作并添加 toRow 并遵循 Andreas 的建议。为安德烈亚斯竖起大拇指

于 2015-01-25T15:07:27.367 回答
5

VDWWD 上面的答案非常适合保持类型安全,我在此基础上进行了一些改进。

  • 方法直接从文件中读取。
  • 通过使用所有行而不是一个值来检测列类型。如果在列中找到多个类型,则将列类型设置为字符串。
  • 在字符串列表中返回的错误消息。

这是更新的版本:

    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;
    }
于 2019-03-19T17:19:11.763 回答
1
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;
            }
        }
于 2013-01-17T07:36:33.217 回答
1
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);

非常感谢提交代码的用户和 Andreas 的建议这里是完成以下更改,我是泛型新手,所以请原谅并纠正我的任何错误请在下面找到修改后的代码它可能对某人有所帮助

  • 添加了Display Annotation 实体模型以与Excel 列名进行映射,以便也可以处理带有空格的列名。
  • 有问题“T objT”,因为它在 for 循环之外,因此导致相同的值重复插入到 List 通过
    实例化循环内部修复它,即使用“new T()”
  • 通过使用“ws.Dimension.Columns”获取列计数而不是 ws.Cells.Count() 来修复列超出范围错误,因为它会导致超出范围列错误
  • 用于循环遍历行数据向它添加了 +1,因为 RowNum=1 正在读取标题名称,所以对“rowNum = fromRow + 1”进行了微小的更改
于 2017-12-20T11:25:19.923 回答
0

在这里,我分享如何阅读excel。您可以修改它以将每个日期存储在数据表中。

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());
            }
        }
    }
}

参考: http ://sforsuresh.in/read-data-excel-sheet-insert-database-table-c/

于 2018-08-23T10:52:16.940 回答
0

如果您想从 excel 中读取每个工作表的数据,以及工作表包含特定列的日期格式数据,请使用以下代码。

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;
    }
于 2019-11-21T10:32:14.057 回答