C＃使用Interop写入打开的Excel文件

Question

我有一个非常艰难的时间，但我需要能够使用Interop连接到一个打开的excel文件，然后写入该文件。

该文件由外部进程打开，然后此应用程序稍后将写入工作簿。我可以让它打开一个文件并写入活动工作簿。但我找不到连接到以前的工作簿并写入的方法。

我一直在使用Marshal.GetActiveObject，但我很快就会在打开多个文件的计算机上运行该应用程序，并且需要写入一个很可能不是活动文件的应用程序。

Answer 1

GetObject可以参考Microsoft.VisualBasic使用（如果需要，它也会打开文件）：

object o = Microsoft.VisualBasic.Interaction.GetObject(@"C:\x.xlsx", "Excel.Application");
var wb = o as Microsoft.Office.Interop.Excel.Workbook; 
if (wb != null) 
{ 
    Microsoft.Office.Interop.Excel.Application xlApp = wb.Application;
    // your code 
}

---

通过查看Microsoft.VisualBasic源代码GetObject可以避免参考https://github.com/Microsoft/referencesource/blob/master/Microsoft.VisualBasic/runtime/msvbalib/Interaction.vb#L1039

Answer 2

这似乎是C＃版本

using Excel = Microsoft.Office.Interop.Excel;
Excel.Application excel = null;
try
{
  excel = (Excel.Application)Marshal.GetActiveObject("Excel.Application");
}
catch (COMException exc)
{
// ....
}

显然假设该文件是由同一台机器上的excel应用程序打开的。

但问题是，Marshal.GetActiveObject将始终返回它在ROT（running object table）上找到的第一个实例。这是因为Office不会注册新对象。您必须从子窗口获取应用程序，就像在这个更复杂的answer中建议的那样。

Answer 3

试试这种方式。

Microsoft.Office.Interop.Excel.Application oXL;
Microsoft.Office.Interop.Excel._Workbook oWB;
Microsoft.Office.Interop.Excel._Worksheet oSheet;
Microsoft.Office.Interop.Excel.Range oRng;
object misvalue = System.Reflection.Missing.Value;
try
{
    //Start Excel and get Application object.
    oXL = new Microsoft.Office.Interop.Excel.Application();
    oXL.Visible = true;

    //Get a new workbook.
    oWB = (Microsoft.Office.Interop.Excel._Workbook)(oXL.Workbooks.Add(""));
    oSheet = (Microsoft.Office.Interop.Excel._Worksheet)oWB.ActiveSheet;

    //Add table headers going cell by cell.
    oSheet.Cells[1, 1] = "First Name";
    oSheet.Cells[1, 2] = "Last Name";
    oSheet.Cells[1, 3] = "Full Name";
    oSheet.Cells[1, 4] = "Salary";

    //Format A1:D1 as bold, vertical alignment = center.
    oSheet.get_Range("A1", "D1").Font.Bold = true;
    oSheet.get_Range("A1", "D1").VerticalAlignment =
        Microsoft.Office.Interop.Excel.XlVAlign.xlVAlignCenter;

    // Create an array to multiple values at once.
    string[,] saNames = new string[5, 2];

    saNames[0, 0] = "John";
    saNames[0, 1] = "Smith";
    saNames[1, 0] = "Tom";

    saNames[4, 1] = "Johnson";

    //Fill A2:B6 with an array of values (First and Last Names).
    oSheet.get_Range("A2", "B6").Value2 = saNames;

    //Fill C2:C6 with a relative formula (=A2 & " " & B2).
    oRng = oSheet.get_Range("C2", "C6");
    oRng.Formula = "=A2 & \" \" & B2";

    //Fill D2:D6 with a formula(=RAND()*100000) and apply format.
    oRng = oSheet.get_Range("D2", "D6");
    oRng.Formula = "=RAND()*100000";
    oRng.NumberFormat = "$0.00";

    //AutoFit columns A:D.
    oRng = oSheet.get_Range("A1", "D1");
    oRng.EntireColumn.AutoFit();

    oXL.Visible = false;
    oXL.UserControl = false;
    oWB.SaveAs("c:\\test\\test505.xls", Microsoft.Office.Interop.Excel.XlFileFormat.xlWorkbookDefault, Type.Missing, Type.Missing,
        false, false, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange,
        Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);

    oWB.Close();

从这里：

How to write some data to excel file(.xlsx)

另外，检查一下。

using System;
using System.Drawing;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel; 

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                System.Data.OleDb.OleDbConnection MyConnection ;
                System.Data.OleDb.OleDbCommand myCommand = new System.Data.OleDb.OleDbCommand();
                string sql = null;
                MyConnection = new System.Data.OleDb.OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0;Data Source='c:\\csharp.net-informations.xls';Extended Properties=Excel 8.0;");
                MyConnection.Open();
                myCommand.Connection = MyConnection;
                sql = "Insert into [Sheet1$] (id,name) values('5','e')";
                myCommand.CommandText = sql;
                myCommand.ExecuteNonQuery();
                MyConnection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show (ex.ToString());
            }
        }
   }
}