C #/. NET 4.0 new features generate Excel documents

Directly run the Code:

using MSExcel = Microsoft.Office.Interop.Excel;public class ExcelHelper{    /// <summary>    /// Creates the excel file by column.    /// </summary>    /// <param name="filename">The filename.</param>    /// <param name="columns">The columns.</param>    public static void CreateExcelFileByColumn (string filename, IEnumerable<ColumnData> columns)    {        createExcelFile (filename, excelApp =>        {            //Write data into the workbook by column.            int columnIndex = 1;            foreach (var column in columns)            {                //Write the header.                excelApp.Cells[1, columnIndex].Value = column.Header;                //Write the following lines in this column.                int rowIndex = 2;                foreach (var cell in column.Data)                {                    excelApp.Cells[rowIndex++, columnIndex].Value = cell;                }                columnIndex++;            }        });    }    /// <summary>    /// Creates the excel file by row.    /// </summary>    /// <param name="filename">The filename.</param>    /// <param name="rows">The rows.</param>    public static void CreateExcelFileByRow (string filename, IEnumerable<IEnumerable> rows)    {        createExcelFile (filename, excelApp =>        {            //Write data into the workbook by row.            int rowIndex = 1;            foreach (var row in rows)            {                int columnIndex = 1;                foreach (var cell in row)                {                    excelApp.Cells[rowIndex, columnIndex++].Value = cell;                }                rowIndex++;            }        });    }    /// <summary>    /// Creates the excel file and perform the specified action.    /// </summary>    /// <param name="filename">The filename.</param>    /// <param name="action">The action.</param>    private static void createExcelFile (string filename, Action<MSExcel.Application> action)    {        //Create the excel application and set it to run in background.        var excelApp = new MSExcel.Application ();        excelApp.Visible = false;        //Add a new workbook.        excelApp.Workbooks.Add ();        //Perform the action.        action (excelApp);        //Save the workbook then close the file.        excelApp.ActiveWorkbook.SaveAs (Filename: filename,             FileFormat: MSExcel.XlFileFormat.xlWorkbookNormal);        excelApp.ActiveWorkbook.Close ();        //Exit the excel application.        excelApp.Quit ();    }}

 

This class provides two methods: Creating an excel file by column data and creating an excel file by row data.

Note that the return value of excelApp. Cells [row, column] is already the dynamic type introduced in. NET 4.0,
Instead of the original object type, you can directly call the. Value () method above, which is dynamically parsed by DLR;
In the past, we had to first convert the returned value to Range and write it:

((MSExcel.Range)excelApp.Cells[row, column]).Value2 = value;

In addition, the introduction of the named parameters and optional parameters in C #4.0 makes the method call to the COM Object equivalent.
Concise, only look at the last SaveAs method. In the past, a bunch of Type. Missing objects must be passed to indicate that this parameter is not passed.
Number or use the default value, such:

excelApp.ActiveWorkbook.SaveAs (filename,    MSExcel.XlFileFormat.xlWorkbookNormal,    Type.Missing, Type.Missing, Type.Missing,    Type.Missing, MSExcel.XlSaveAsAccessMode.xlNoChange,    Type.Missing, Type.Missing, Type.Missing,    Type.Missing, Type.Missing); 

 

It is a headache. Now you only need to specify the parameter to be given with the name parameter. Other parameters are automatically used because they are optional.
Default Value:

excelApp.ActiveWorkbook.SaveAs (Filename: filename,    FileFormat: MSExcel.XlFileFormat.xlWorkbookNormal);

 

The meaning is very clear.

Finally, add the definition of the simple ColumnData class:

/// <summary>/// Represents the header and data of a column./// </summary>public class ColumnData{    /// <summary>    /// Gets or sets the header.    /// </summary>    /// <value>The header.</value>    public string Header { get; set; }    /// <summary>    /// Gets or sets the data.    /// </summary>    /// <value>The data.