如何在c＃中删除网络打印机连接

Question

我的最终目标是在本地工作站上取消映射特定的网络打印机。我尝试过WMI，Windows Script Host和Winspool.drv Win32 API。我对任何方向的想法持开放态度。

使用WMI时，我有以下简化函数，主要是从http://www.codeproject.com/Articles/80680/Managing-Printers-Programatically-using-C-and-WMI复制的：

    public void unmapPrinter()
    {
        ManagementClass win32Printer = new ManagementClass("Win32_Printer");
        ManagementObjectCollection printers = win32Printer.GetInstances();
        foreach (ManagementObject printer in printers)
        {
            printer.Delete();
        }
    }

在Windows 8.1上以示例用户之一或管理员身份执行此操作将返回“Access Denied”，其中包含以下堆栈跟踪：

at System.Management.ManagementException.ThrowWithExtendedInfo(ManagementStatus errorCode)
at System.Management.ManagementObject.Delete(DeleteOptions options)
at System.Management.ManagementObject.Delete()
at PrintCentralClient.Workstation.unmapPrinter(Printer printerToRemove) in C:\projects\PrintCentralClient\PrintCentralClient\Workstation.cs:line 247
at PrintCentralClient.Program.unmapPrinters(FileLogger log, Workstation workstation) in C:\projects\PrintCentralClient\PrintCentralClient\Program.cs:line 310
at PrintCentralClient.Program.Main(String[] args) in C:\projects\PrintCentralClient\PrintCentralClient\Program.cs:line 75
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()

PowerShell中的相同想法，抓取Win32_Printer实例并对它们执行删除工作。

$printers = gwmi Win32_Printer
$printers[i].Delete()

有关我为什么使用我的C＃代码拒绝访问的任何想法？在代码的其他地方，我成功使用了Win32_Printer.AddPrinterConnection（）方法。

谢谢。

编辑1：使用Windows Scripting Host错误“此网络连接不存在”。

演示功能：

    public void unmapPrinterViaWSH()
    {
        IWshNetwork_Class network = new IWshNetwork_Class();
        network.RemovePrinterConnection(@"\\<server>\<printerName>", true, true);
    }

我尝试了一些变化，包括将删除行更改为：

network.RemovePrinterConnection("\\\\<server>\\<printerName>", true, true)

我还尝试枚举打印机连接并使用确切的名称字符串进行删除：

    public void unmapPrinterViaWSH(Printer printerToRemove)
    {
        IWshNetwork_Class network = new IWshNetwork_Class();
        IWshCollection printers = network.EnumPrinterConnections();
        foreach (object printer in printers)
        {
            if (printer.ToString() == printerToRemove.mappedNameToString())
            {
                network.RemovePrinterConnection(printer.ToString(), true, true);
            }
        }
    }

这失败了同样的“网络连接不存在”错误。

Answer 1

四个蛮力：

我错过了ConnectionsOptions。最初提供的代码示例与它们没有任何关系。在进行早期测试时，我总是先创建范围，然后选择选项。我发现的另一个参考是反过来的。这似乎有效。下面是一个适合我的代码示例：

public void unmapPrinter()
{
    ConnectionOptions options = new ConnectionOptions();
    options.EnablePrivileges = true;
    ManagementScope scope = new ManagementScope(ManagementPath.DefaultPath, options);
    scope.Connect();
    ManagementClass win32Printer = new ManagementClass("Win32_Printer");
    ManagementObjectCollection printers = win32Printer.GetInstances();
    foreach (ManagementObject printer in printers)
    {
        printer.Delete();
    }
}

Answer 2

如果您只想删除特定的打印机，可以执行以下操作：

using (var printer = new ManagementObject($"Win32_Printer.DeviceID='{printerPath}'"))
    printer.Delete();