c# setting a printer | 易学教程

问题

Hello and thank you for you time on this question, I'm trying change a Active Printer according to the choice that user chooses in excel. However I'm having some trouble. For some reason it keeps giving me the same error.

"An exception of type 'System.Runtime.InteropServices.COM Exception' occurred in DailyReport.dll but was not handled in user code Exception from HRESULT:0X800A03EC"

I've been goggling this error and im having a hard time finding anything, I did find a link COM Exception and they provided a link to another website but seems when I try to go that site it doesn't open.

I have Tried:

xlApp.ActivePrinter = "CORPPRT58-Copier Room on RR-PS1:";

xlApp.ActivePrinter = "\\RR-PS1\CORPPRT58-Copier Room"; 

xlApp.ActivePrinter = "CORPPRT58-Copier Room on RR-PS1";

I have checked to make sure that the printer is installed and it is. if someone could point me in the correct direction that would be great thanks!!

回答1:

The correct answer is (i.e.):

xlApp.ActivePrinter = "\\\\RR-PS1\\CORPPRT58-Copier Room on Ne00:";

An important part is the 'Ne00:' This is the port on which this printer can be found. This is different on each computer and can be found in registry at HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Devices.

Another problem is the concatenation string 'on'. This may be valid when working with an English excel but it's translated to other languages!

I had the same problem but there aren't many complete examples I could find so here is mine:

// Open excel document
var path = @"c:\path\to\my\doc.xlsx";

Microsoft.Office.Interop.Excel.Application _xlApp;
Microsoft.Office.Interop.Excel.Workbook _xlBook;
_xlApp = new Microsoft.Office.Interop.Excel.Application();
_xlBook = _xlApp.Workbooks.Open(path);
_xlBook.Activate();

var printer = @"EPSON LQ-690 ESC/P2";
var port = String.Empty;

// Find correct printerport
using (RegistryKey key = Registry.CurrentUser.OpenSubKey(path))
{
    if (key != null)
    {
        object value = key.GetValue(printer);
        if (value != null)
        {
            string[] values = value.ToString().Split(',');
            if (values.Length >= 2) port = values[1];
        }
    }
}

// Set ActivePrinter if not already set
if (!_xlApp.ActivePrinter.StartsWith(printer))
{
    // Get current concatenation string ('on' in enlgish, 'op' in dutch, etc..)
    var split = _xlApp.ActivePrinter.Split(' ');
    if (split.Length >= 3)
    {
        _xlApp.ActivePrinter = String.Format("{0} {1} {2}",
            printer, 
            split[split.Length - 2], 
            port);
    }
}

// Print document
_xlBook.PrintOutEx();

It's far for perfect since I'm not aware of any other translations. If 'on' is translated with spaces, above will fail. But i'm guessing that the solution will work for most clients. You can easily get the current concatenation string by looking at the currect value of ActivePrinter.

A more failproof method would be to strip the printer name and the assigned port and what remains is the concatenation string. But then you would have to loop through all installed printers and check for a match.

Another test I personally do it check if the printer is installed on the system:

if(PrinterSettings.InstalledPrinters.Cast<string>().ToList().Contains(printer)) {
    //Set active printer...
}

来源：https://stackoverflow.com/questions/29921150/c-sharp-setting-a-printer

标签

excel

printing