Question

protected override void OnBeforeInstall(IDictionary savedState)
{
    base.OnBeforeInstall(savedState);
    DialogResult result = DialogResult.None;
    if (isExcelIsRunning())
    {
        result = MessageBox.Show("Excel is still running. Please save your work and close Excel, and then click \"Retry\" button to continue with installation.", "", MessageBoxButtons.RetryCancel, MessageBoxIcon.Warning);
    }
    while (result == DialogResult.Retry)
    {
        if (!isExcelIsRunning())
        {
            break;
        }
    }
}


//check if excel is currently running
private bool isExcelIsRunning()
{
    bool flag = false;
    Process[] xlProc = Process.GetProcessesByName("excel");
    if (xlProc != null)
        flag = true;
    return flag;
}

The above is the code I am about to use for my Installer Class.

What I want to achieve here is that I need the installer to check whether or not Excel is currently running during the installation. And if it is running, then there should be a pop-up message at the start of installation to alert user to close off Excel and the installer should pause until there’s no Excel instance found in the process list any more.

Back to the code, I don’t think that while block is quite right, as it could cause an endless loop after user clicks “Retry” button if in the mean time Excel is still running.

So what’d be the better approach? Would anyone here take a look at the above code and see where I can improve?

Answer 1

I think your code would be something like this:

while(isExcelRunning())
{
    var result = MessageBox.Show("Excel is still running. Please save your work and close Excel, and then click \"Retry\" button to continue with installation.", "", MessageBoxButtons.RetryCancel, MessageBoxIcon.Warning);
    if (result != DialogResult.Retry)
    {
         //Handle Cancel
         break;
    }
}

This will keep displaying the alert in a loop, either until Excel exits, or they press cancel, at which you can do whatever you need to do; then we exit the loop (or you could return entirely out of the method).

The key here is display the alert repetitively, either until Excel is gone or they choose to cancel. If you need to do some code after the loop based on the response; perhaps something like this:

var userHasCancelled = false;
while(!userHasCancelled && isExcelRunning())
{
    var result = MessageBox.Show("Excel is still running. Please save your work and close Excel, and then click \"Retry\" button to continue with installation.", "", MessageBoxButtons.RetryCancel, MessageBoxIcon.Warning);
    if (result != DialogResult.Retry)
    {
         userHasCancelled = true;
    }
}
if (userHasCancelled)
{
    //User cancelled...
}
else
{
    //Continue.
}