[c#] How to open an Excel file in C#?

I am trying to convert some VBA code to C#. I am new to C#. Currently I am trying to open an Excel file from a folder and if it does not exist then create it. I am trying something like the following. How can I make it work?

Excel.Application objexcel;
Excel.Workbook wbexcel;
bool wbexists;
Excel.Worksheet objsht;
Excel.Range objrange;

objexcel = new Excel.Application();
if (Directory("C:\\csharp\\error report1.xls") = "")
{
    wbexcel.NewSheet();
}

else
{
    wbexcel.Open("C:\\csharp\\error report1.xls");
    objsht = ("sheet1");
}
objsht.Activate();

For opening a file, try this:

objexcel.Workbooks.Open(@"C:\YourPath\YourExcelFile.xls",
    missing, missing, missing, missing, missing, missing, missing,
    missing, missing, missing, missing, missing,missing, missing);

You must supply those stupid looking 'missing' arguments. If you were writing the same code in VB.Net you wouldn't have needed them, but you can't avoid them in C#.

Is this a commercial application or some hobbyist / open source software?

I'm asking this because in my experience, all free .NET Excel handling alternatives have serious problems, for different reasons. For hobbyist things, I usually end up porting jExcelApi from Java to C# and using it.

But if this is a commercial application, you would be better off by purchasing a third party library, like Aspose.Cells. Believe me, it totally worths it as it saves a lot of time and time ain't free.

It's easier to help you if you say what's wrong as well, or what fails when you run it.

But from a quick glance you've confused a few things.

The following doesn't work because of a couple of issues.

if (Directory("C:\\csharp\\error report1.xls") = "")

What you are trying to do is creating a new Directory object that should point to a file and then check if there was any errors.

What you are actually doing is trying to call a function named Directory() and then assign a string to the result. This won't work since 1/ you don't have a function named Directory(string str) and you cannot assign to the result from a function (you can only assign a value to a variable).

What you should do (for this line at least) is the following

FileInfo fi = new FileInfo("C:\\csharp\\error report1.xls");
if(!fi.Exists)
{
    // Create the xl file here
}
else
{
    // Open file here
}

As to why the Excel code doesn't work, you have to check the documentation for the Excel library which google should be able to provide for you.

For opening a file, try this:

objexcel.Workbooks.Open(@"C:\YourPath\YourExcelFile.xls",
    missing, missing, missing, missing, missing, missing, missing,
    missing, missing, missing, missing, missing,missing, missing);

You must supply those stupid looking 'missing' arguments. If you were writing the same code in VB.Net you wouldn't have needed them, but you can't avoid them in C#.

Imports

 using Excel= Microsoft.Office.Interop.Excel;
 using Microsoft.VisualStudio.Tools.Applications.Runtime;

Here is the code to open an excel sheet using C#.

    Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
    Microsoft.Office.Interop.Excel.Workbook wbv = excel.Workbooks.Open("C:\\YourExcelSheet.xlsx");
    Microsoft.Office.Interop.Excel.Worksheet wx = excel.ActiveSheet as Microsoft.Office.Interop.Excel.Worksheet;

    wbv.Close(true, Type.Missing, Type.Missing);
    excel.Quit();

Here is a video mate on how to open an excel worksheet using C# https://www.youtube.com/watch?v=O5Dnv0tfGv4

Is this a commercial application or some hobbyist / open source software?

I'm asking this because in my experience, all free .NET Excel handling alternatives have serious problems, for different reasons. For hobbyist things, I usually end up porting jExcelApi from Java to C# and using it.

But if this is a commercial application, you would be better off by purchasing a third party library, like Aspose.Cells. Believe me, it totally worths it as it saves a lot of time and time ain't free.

Is this a commercial application or some hobbyist / open source software?

I'm asking this because in my experience, all free .NET Excel handling alternatives have serious problems, for different reasons. For hobbyist things, I usually end up porting jExcelApi from Java to C# and using it.

But if this is a commercial application, you would be better off by purchasing a third party library, like Aspose.Cells. Believe me, it totally worths it as it saves a lot of time and time ain't free.

Code :

 private void button1_Click(object sender, EventArgs e)
     {

        textBox1.Enabled=false;

            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "Excell File |*.xlsx;*,xlsx";
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                string extn = Path.GetExtension(ofd.FileName);
                if (extn.Equals(".xls") || extn.Equals(".xlsx"))
                {
                    filename = ofd.FileName;

                    if (filename != "")
                    {
                        try
                        {
                            string excelfilename = Path.GetFileName(filename);


                        }
                        catch (Exception ew)
                        {
                            MessageBox.Show("Errror:" + ew.ToString());
                        }
                    }
                }
            }

open Excel file

System.Diagnostics.Process.Start(@"c:\document.xls");

Imports

 using Excel= Microsoft.Office.Interop.Excel;
 using Microsoft.VisualStudio.Tools.Applications.Runtime;

Here is the code to open an excel sheet using C#.

    Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
    Microsoft.Office.Interop.Excel.Workbook wbv = excel.Workbooks.Open("C:\\YourExcelSheet.xlsx");
    Microsoft.Office.Interop.Excel.Worksheet wx = excel.ActiveSheet as Microsoft.Office.Interop.Excel.Worksheet;

    wbv.Close(true, Type.Missing, Type.Missing);
    excel.Quit();

Here is a video mate on how to open an excel worksheet using C# https://www.youtube.com/watch?v=O5Dnv0tfGv4

It's easier to help you if you say what's wrong as well, or what fails when you run it.

But from a quick glance you've confused a few things.

The following doesn't work because of a couple of issues.

if (Directory("C:\\csharp\\error report1.xls") = "")

What you are trying to do is creating a new Directory object that should point to a file and then check if there was any errors.

What you are actually doing is trying to call a function named Directory() and then assign a string to the result. This won't work since 1/ you don't have a function named Directory(string str) and you cannot assign to the result from a function (you can only assign a value to a variable).

What you should do (for this line at least) is the following

FileInfo fi = new FileInfo("C:\\csharp\\error report1.xls");
if(!fi.Exists)
{
    // Create the xl file here
}
else
{
    // Open file here
}

As to why the Excel code doesn't work, you have to check the documentation for the Excel library which google should be able to provide for you.

you should open like this

        Excel.Application xlApp ;
        Excel.Workbook xlWorkBook ;
        Excel.Worksheet xlWorkSheet ;
        object misValue = System.Reflection.Missing.Value;

        xlApp = new Excel.ApplicationClass();
        xlWorkBook = xlApp.Workbooks.Open("csharp.net-informations.xls", 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
        xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

source : http://csharp.net-informations.com/excel/csharp-open-excel.htm

ruden

Microsoft.Office.Interop.Excel.Application excapp;

excapp = new Microsoft.Office.Interop.Excel.Application();

object misval=System.Reflection.Missing.Value;

Workbook wrkbuk = new Workbook();

Worksheet wrksht = new Worksheet();

wrkbuk = excapp.Workbooks._Open(@"C:\Users\...\..._template_v1.0.xlsx", misval, misval, 
misval, misval, misval, misval, misval, misval, misval, misval, misval, misval);

wrksht = (Microsoft.Office.Interop.Excel.Worksheet)wrkbuk.Worksheets.get_Item(2);

FileInfo fi = new FileInfo("C:\\test\\report.xlsx");
if(fi.Exists)
{
    System.Diagnostics.Process.Start(@"C:\test\report.xlsx");
}
else
{
    //file doesn't exist
}

For opening a file, try this:

objexcel.Workbooks.Open(@"C:\YourPath\YourExcelFile.xls",
    missing, missing, missing, missing, missing, missing, missing,
    missing, missing, missing, missing, missing,missing, missing);

You must supply those stupid looking 'missing' arguments. If you were writing the same code in VB.Net you wouldn't have needed them, but you can't avoid them in C#.

It's easier to help you if you say what's wrong as well, or what fails when you run it.

But from a quick glance you've confused a few things.

The following doesn't work because of a couple of issues.

if (Directory("C:\\csharp\\error report1.xls") = "")

What you are trying to do is creating a new Directory object that should point to a file and then check if there was any errors.

What you are actually doing is trying to call a function named Directory() and then assign a string to the result. This won't work since 1/ you don't have a function named Directory(string str) and you cannot assign to the result from a function (you can only assign a value to a variable).

What you should do (for this line at least) is the following

FileInfo fi = new FileInfo("C:\\csharp\\error report1.xls");
if(!fi.Exists)
{
    // Create the xl file here
}
else
{
    // Open file here
}

As to why the Excel code doesn't work, you have to check the documentation for the Excel library which google should be able to provide for you.

For opening a file, try this:

objexcel.Workbooks.Open(@"C:\YourPath\YourExcelFile.xls",
    missing, missing, missing, missing, missing, missing, missing,
    missing, missing, missing, missing, missing,missing, missing);

You must supply those stupid looking 'missing' arguments. If you were writing the same code in VB.Net you wouldn't have needed them, but you can't avoid them in C#.

For editing Excel files from within a C# application, I recently started using NPOI. I'm very satisfied with it.

private void btnChoose2_Click(object sender, EventArgs e)
{
  OpenFileDialog openfileDialog1 = new OpenFileDialog();
  if (openfileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
  {
    this.btnChoose2.Text = openfileDialog1.FileName;
    String filename = DialogResult.ToString();

    var excelApp = new Excel.Application();
    excelApp.Visible = true;
    excelApp.Workbooks.Open(btnChoose2.Text);
  }
}

It's easier to help you if you say what's wrong as well, or what fails when you run it.

But from a quick glance you've confused a few things.

The following doesn't work because of a couple of issues.

if (Directory("C:\\csharp\\error report1.xls") = "")

What you are trying to do is creating a new Directory object that should point to a file and then check if there was any errors.

What you are actually doing is trying to call a function named Directory() and then assign a string to the result. This won't work since 1/ you don't have a function named Directory(string str) and you cannot assign to the result from a function (you can only assign a value to a variable).

What you should do (for this line at least) is the following

FileInfo fi = new FileInfo("C:\\csharp\\error report1.xls");
if(!fi.Exists)
{
    // Create the xl file here
}
else
{
    // Open file here
}

As to why the Excel code doesn't work, you have to check the documentation for the Excel library which google should be able to provide for you.

Code :

 private void button1_Click(object sender, EventArgs e)
     {

        textBox1.Enabled=false;

            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "Excell File |*.xlsx;*,xlsx";
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                string extn = Path.GetExtension(ofd.FileName);
                if (extn.Equals(".xls") || extn.Equals(".xlsx"))
                {
                    filename = ofd.FileName;

                    if (filename != "")
                    {
                        try
                        {
                            string excelfilename = Path.GetFileName(filename);


                        }
                        catch (Exception ew)
                        {
                            MessageBox.Show("Errror:" + ew.ToString());
                        }
                    }
                }
            }

open Excel file

System.Diagnostics.Process.Start(@"c:\document.xls");

you should open like this

        Excel.Application xlApp ;
        Excel.Workbook xlWorkBook ;
        Excel.Worksheet xlWorkSheet ;
        object misValue = System.Reflection.Missing.Value;

        xlApp = new Excel.ApplicationClass();
        xlWorkBook = xlApp.Workbooks.Open("csharp.net-informations.xls", 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
        xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

source : http://csharp.net-informations.com/excel/csharp-open-excel.htm

ruden

FileInfo fi = new FileInfo("C:\\test\\report.xlsx");
if(fi.Exists)
{
    System.Diagnostics.Process.Start(@"C:\test\report.xlsx");
}
else
{
    //file doesn't exist
}

private void btnChoose2_Click(object sender, EventArgs e)
{
  OpenFileDialog openfileDialog1 = new OpenFileDialog();
  if (openfileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
  {
    this.btnChoose2.Text = openfileDialog1.FileName;
    String filename = DialogResult.ToString();

    var excelApp = new Excel.Application();
    excelApp.Visible = true;
    excelApp.Workbooks.Open(btnChoose2.Text);
  }
}

Microsoft.Office.Interop.Excel.Application excapp;

excapp = new Microsoft.Office.Interop.Excel.Application();

object misval=System.Reflection.Missing.Value;

Workbook wrkbuk = new Workbook();

Worksheet wrksht = new Worksheet();

wrkbuk = excapp.Workbooks._Open(@"C:\Users\...\..._template_v1.0.xlsx", misval, misval, 
misval, misval, misval, misval, misval, misval, misval, misval, misval, misval);

wrksht = (Microsoft.Office.Interop.Excel.Worksheet)wrkbuk.Worksheets.get_Item(2);

For editing Excel files from within a C# application, I recently started using NPOI. I'm very satisfied with it.

Is this a commercial application or some hobbyist / open source software?

I'm asking this because in my experience, all free .NET Excel handling alternatives have serious problems, for different reasons. For hobbyist things, I usually end up porting jExcelApi from Java to C# and using it.

But if this is a commercial application, you would be better off by purchasing a third party library, like Aspose.Cells. Believe me, it totally worths it as it saves a lot of time and time ain't free.