保存/恢复打印机 DevModes - wxPython / win32print

Question

到目前为止，我发现了两种不同的方法来访问我认为是等效的打印机 DevMode 版本，这些都是通过 wxPython 用户界面实现的：

window = wx.GetTopLevelWindows()[0].GetHandle()
name = self.itemMap['device'].GetValue() # returns a valid printer name.
handle = win32print.OpenPrinter(name)
dmin = None
dmout = pywintypes.DEVMODEType()
mode = DM_IN_BUFFER | DM_OUT_BUFFER | DM_IN_PROMPT

res = win32print.DocumentProperties(window, handle, name, dmout, dmin, mode)

if res == 1:
  print dmout.DriverData

还有一种方法是

dlg = wx.PrintDialog(self, dgData)

res = dlg.ShowModal()

if res == wx.ID_OK:
  print dlg.GetPrintDialogData().PrintData.GetPrivData()

这两种二进制结构似乎包含了控制设备输出行为所需的信息。这很好，但问题是，不能直接用这些存储的 devmode 数据来重新加载打印设置对话框。在第一种情况下，PyDEVMODE 对象包含了几十个需要手动设置的属性（PyDEVMODE 参考）。而在第二种情况下，有一些 Getter / Setter 方法可以控制部分属性，但并不是所有的属性都能控制（wxPrintData 参考）。有没有人知道如何从实际的 DevMode（二进制数据）创建一个 Python Devmode 对象？我对这两种方法都可以接受，差别不大。我希望能避免每次都手动存储或重置每个属性，以便对话框能够在正确的状态下重新打开。

Answer 1

你还可以通过一个新的命名对象来编辑 pDevMode 这个对象，方法是在 win32print.GetPrinter() 中进行操作。

    import win32print, os

    name = win32print.GetDefaultPrinter()
    printdefaults = {"DesiredAccess": win32print.PRINTER_ACCESS_USE}
    handle = win32print.OpenPrinter(name, printdefaults)
    level = 2
    attributes = win32print.GetPrinter(handle, level)   
    # http://timgolden.me.uk/pywin32-docs/PyDEVMODE.html
    # Note: All pDevMode settings are int() variables

    attributes['pDevMode'].Copies = 2    # Num of copies

    #attributes['pDevMode'].Color = 1    # Color
    attributes['pDevMode'].Color = 2    # Monochrome

    attributes['pDevMode'].Collate = 1    # Collate TRUE
    #attributes['pDevMode'].Collate = 2    # Collate FALSE

我在类似的问题中扩展了 Yuri Gendelman 提供的“属性”命名结构：通过 Python 打印 PDF 文件的双面模式

下面是我在代码中使用它的一个示例。

    import win32print, os

    def autoprint(user):                     
        name = win32print.GetDefaultPrinter()
        printdefaults = {"DesiredAccess": win32print.PRINTER_ACCESS_USE}
        handle = win32print.OpenPrinter(name, printdefaults)
        level = 2
        attributes = win32print.GetPrinter(handle, level)   # http://timgolden.me.uk/pywin32-docs/PyDEVMODE.html
                                       # All are int() variables
        attributes['pDevMode'].Duplex = 1    # no flip
        #attributes['pDevMode'].Duplex = 2    # flip up
        #attributes['pDevMode'].Duplex = 3    # flip over

        attributes['pDevMode'].Copies = 2    # Num of copies

        #attributes['pDevMode'].Color = 1    # Color
        attributes['pDevMode'].Color = 2    # Monochrome

        attributes['pDevMode'].Collate = 1    # Collate TRUE
        #attributes['pDevMode'].Collate = 2    # Collate FALSE

        try:
            win32print.SetPrinter(handle, level, attributes, 0)
        except:
            print("win32print.SetPrinter: settings could not be changed")

        try:
            newfile_name = max([downloadPath + "\\" + user["FULL_NAME"] + "PDFToBePrinted.pdf"])
            Print2Copies = win32api.ShellExecute(0, 'print', newfile_name, None, '.', 0)
            time.sleep(1)

            Print2Copies 
            print("Printing now...")
            win32print.ClosePrinter(handle)

            final_filename = max([downloadPath + "\\" + user["FULL_NAME"] + "Printed.pdf"])
            os.rename(newfile_name, final_filename)

        except Exception as e:
            print(str(e))
            print("--Failed to print--")
            time.sleep(5)

这是检查默认设置的代码：

win32print.GetPrinter(handle, level)['pDevMode'].Copies win32print.GetPrinter(handle, level)['pDevMode'].Duplex

In[115]: print(win32print.GetPrinter(handle, level)['pDevMode'].Copies)
Out[115]: 1

In[116]:win32print.GetPrinter(handle, level)['pDevMode'].Duplex
Out[116]: 1

In[117]:win32print.GetPrinter(handle, level)['pDevMode'].Color
Out[117]: 1

这里是你可以通过 pDevMode 更改的其他打印机设置：http://timgolden.me.uk/pywin32-docs/PyDEVMODE.html

Answer 2

看起来目前在Python中没有简单优雅的方法可以直接做到这一点。我能想到的最接近的办法是用C++写了一个dll文件，我可以调用它。这样我就能得到完整的二进制DevMode结构，并且可以从中重新加载。那个C++ dll的代码大概是这样的：

#include "stdafx.h"
#include <iobind/base64_policy.hpp>

#include <string>
#ifdef _UNICODE
    typedef std::wstring string_t;
#else
    typedef std::string string_t;
#endif
typedef std::string cstring;


extern "C" BOOL WINAPI DllMain( HMODULE hModule, DWORD dwReason, LPVOID lpReserved ) {
    switch ( dwReason ){
        case DLL_PROCESS_ATTACH:
            DisableThreadLibraryCalls( hModule );
            break;
        case DLL_PROCESS_DETACH:
            break;
    }

    return TRUE;
}


extern "C" DOEXPORT int CleanupA( char *output ) {
    if ( output ) {
        free( output );
        output = NULL;
    }
    return 0;
}


extern "C" DOEXPORT int CleanupW( wchar_t *output ) {
    if ( output ) {
        free( output );
        output = NULL;
    }
    return 0;
}


extern "C" DOEXPORT int printer_setup( 
        void *handle, const TCHAR *printer_in, const char *input,
        int local_only, TCHAR **printer, char **output ) 
{
    HWND hwnd = (HWND)handle;   
    HRESULT hResult = 0;

    LPPRINTDLG pPD = NULL;
    LPPRINTPAGERANGE pPageRanges = NULL;

    // Allocate structure.
    pPD = (LPPRINTDLG)GlobalAlloc(GPTR, sizeof(PRINTDLG));
    if (!pPD) return E_OUTOFMEMORY;

    //  Initialize structure.
    pPD->lStructSize = sizeof(PRINTDLG);
    pPD->hwndOwner = hwnd;

    pPD->hDevMode = NULL;
    if ( input ){
        std::string dec = iobind::encode( input, iobind::from_base64_p );
        if ( !dec.empty() ) {
            HGLOBAL devmode = pPD->hDevMode = ::GlobalAlloc(GPTR, dec.size());
            if ( devmode ){         
                LPDEVMODE src = (LPDEVMODE)&dec[0];
                memcpy( devmode, src, dec.size() );
            }
        }
    }

    pPD->hDevNames = NULL;
    if ( printer_in ){
        HGLOBAL printer = pPD->hDevNames = ::GlobalAlloc(GPTR, sizeof(DEVNAMES)+_tcslen(printer_in)*sizeof(TCHAR)+sizeof(TCHAR));
        if ( printer ){
            LPDEVNAMES dv = (LPDEVNAMES)printer;
            dv->wDefault = 0;
            dv->wDriverOffset = 0;
            dv->wOutputOffset = 0;
            dv->wDeviceOffset = sizeof(DEVNAMES)/sizeof(TCHAR);
            TCHAR *dest = (TCHAR *)(unsigned long)dv + dv->wDeviceOffset;
            _tcscpy( dest, printer_in );
        }
    }

    pPD->hDC = NULL;
    pPD->Flags = PD_PRINTSETUP;

    if ( local_only ) {
        pPD->Flags |= /*PD_ENABLESETUPHOOK |*/ PD_NONETWORKBUTTON;
    }

    pPD->nMinPage = 1;
    pPD->nMaxPage = 1000;
    pPD->nCopies = 1;
    pPD->hInstance = 0;
    pPD->lpPrintTemplateName = NULL;

    //  Invoke the Print property sheet.
    hResult = PrintDlg(pPD);
    if ( hResult != 0 ) {
        if ( pPD->hDevMode ) {
            LPDEVMODE devmode = (LPDEVMODE)::GlobalLock( pPD->hDevMode );
            size_t size = devmode->dmSize + devmode->dmDriverExtra;
            if ( output ) {
                std::string tmp;
                tmp.resize( size );
                memcpy( &tmp[0], devmode, tmp.size() );

                std::string enc = iobind::encode( tmp, iobind::to_base64_p );
                *output = _strdup( enc.c_str() );
            }
            ::GlobalUnlock( pPD->hDevMode );
        }

        if ( pPD->hDevNames ) {
            LPDEVNAMES devnames = (LPDEVNAMES)::GlobalLock( pPD->hDevNames );
            TCHAR *device = (TCHAR *)(unsigned long)devnames + devnames->wDeviceOffset;
            *printer = _tcsdup(device);
            ::GlobalUnlock( pPD->hDevNames );
        }
    }
    else {
        DWORD dlgerr = ::CommDlgExtendedError();
        hResult = dlgerr;
    }

    if (pPD->hDC != NULL) {
        DeleteDC( pPD->hDC );
    }
    if (pPD->hDevMode != NULL) { 
        GlobalFree( pPD->hDevMode );
    }
    if (pPD->hDevNames != NULL) {
        GlobalFree( pPD->hDevNames );
    }
    return hResult;
}

在Python中调用它的方式是这样的：

client = ctypes.cdll.LoadLibrary(os.path.join(myDir, 'rpmclient.dll'))
client.printer_setup.argtypes = [ctypes.c_void_p,
                                 ctypes.c_wchar_p,
                                 ctypes.c_char_p,
                                 ctypes.c_int32,
                                 ctypes.POINTER(ctypes.c_wchar_p),
                                 ctypes.POINTER(ctypes.c_char_p)]

client.printer_setup.restype = ctypes.c_int32
client.CleanupA.argtypes = [ctypes.c_char_p]
client.CleanupA.restype = ctypes.c_int32
client.CleanupW.argtypes = [ctypes.c_wchar_p]
client.CleanupW.restype = ctypes.c_int32

p_in = ctypes.c_wchar_p(self.itemMap['device'].GetValue())
p_out = ctypes.c_wchar_p()

d_in = ctypes.c_char_p(getattr(self, 'devmode', ''))
d_out = ctypes.c_char_p()

res = client.printer_setup(self.GetHandle(),
                           p_in,
                           d_in,
                           False,
                           p_out,
                           d_out)

if res == 0:
  return

if res > 1:
  # Error display code here.

  return

self.devmode = d_out.value