Opening an Excel file in C# using Process.Start

Question

I'm trying to open an excel file using a button click. And for some reason it's not working. I've tried several things. Any ideas why they are not working?

Method 1 I have tried. This opens the file manager but does not open the proper file. It is definitely using the proper path to the file and the file does exist

private string fileCopy;

public RepairResultsControl()
{
    InitializeComponent();
}

public void Show(PSRepair.AnalysisResults analysis, string pathNameCopy)
{
    fileCopy = pathNameCopy;
    Show();
}

private void btnGoToFile_Click(object sender, EventArgs e)
{
    Process.Start("explorer.exe", "/select,"+ fileCopy);
}

Method 2. This just didn't open anything not sure why

System.Diagnostics.Process.Start(@"C:\Users\username\Documents\newTest.xlsx");

Answer 1

Normally, Process.Start(@"C:\Users\username\Documents\newTest.xlsx"); would open your document in Excel.

However, you say in a comment that you are doing this from an Excel add-in which runs in the background. The solution needs to take this into account (the code sample assumes that you have a VSTO add-in, otherwise you need to adjust accordingly):

// make the running Excel instance visible
Globals.ThisAddIn.Application.Visible = true;

// open the workbook using Excel interop
Globals.ThisAddIn.Application.Workbooks.Open(fileName);