PrintDlgEx 无效参数，而 PrintDlg 有效答案

【问题标题】：PrintDlgEx invalid argument, while PrintDlg worksPrintDlgEx 无效参数，而 PrintDlg 有效
【发布时间】：2022-10-01 08:23:42
【问题描述】：

问题：我需要让PrintDlgEx 为我的项目工作，但选项或参数的组合对我不起作用。它为任何选项组合提供E_INVALIDARG，就像我从 Microsoft 示例或其他在线示例中复制的那样。

用PRINTDLG 替换PRINTDLGEX 和用PrintDlg 替换PrintDlgEx（并且只从PRINTDLGEX 中删除选项组）效果很好。

不幸的是，我需要PrintDlgEx，因为我真的需要Apply 按钮来更改打印机或属性表而不打印，用于设计和预览。

请帮我找出为什么我无法显示对话框。

代码：虽然我简化了部分，比如成功返回时应该发生的事情，或者设置DEVMODE 和DEVNAMES，但我完全尝试了这个函数，结果相同：无效参数。

#include <QDebug>
#include <QWindow>
#include <windows.h>
void showPrintDialog()
{
    // Simplifying the setup: real code passes in a QWidget *
    QWidget *caller = this;
    // Not returning a value or doing any work. I just want the dialog to pop up for now

    // Create the standard windows print dialog
    PRINTDLGEX printDialog;
    memset(&printDialog, 0, sizeof(PRINTDLGEX));
    printDialog.lStructSize = sizeof(PRINTDLGEX);

    printDialog.Flags = PD_RETURNDC |           // Return a printer device context. Without this, HDC may be undefined
                        PD_USEDEVMODECOPIESANDCOLLATE |
                        PD_NOSELECTION |        // Don\'t allow selecting individual document pages to print
                        PD_NOPAGENUMS |         // Disables some boxes
                        PD_NOCURRENTPAGE |      // Disables some boxes
                        PD_NONETWORKBUTTON |    // Don\'t allow networking  (but it show \"Find printer\") so what does this do ?
                        PD_HIDEPRINTTOFILE;     // Don\'t allow print to file

    // Only on PRINTDLGEX
        // Theis block copied from https://learn.microsoft.com/en-us/windows/win32/dlgbox/using-common-dialog-boxes?redirectedfrom=MSDN
        // I have tried multiple combinations of options, including none, I really don\'t want any of them
        printDialog.nStartPage = START_PAGE_GENERAL;
        printDialog.nPageRanges = 1;
        printDialog.nMaxPageRanges = 10;
        LPPRINTPAGERANGE pageRange = (LPPRINTPAGERANGE) GlobalAlloc(GPTR, 10 * sizeof(PRINTPAGERANGE));
        printDialog.lpPageRanges = pageRange;
        printDialog.lpPageRanges[0].nFromPage = 1;
        printDialog.lpPageRanges[0].nToPage = 1;
        printDialog.Flags2 = 0;
        printDialog.ExclusionFlags = 0;
        printDialog.dwResultAction = 0; // This will tell me if PRINT

        // Rest of options are also on PRINTDLG
        printDialog.nMinPage = 1;
        printDialog.nMaxPage = 10;

    // The only options I really need
    printDialog.nCopies = 1;
    printDialog.hDevMode = Q_NULLPTR;   // which will be better once this works
    printDialog.hDevNames = Q_NULLPTR;   // which will be better once this works
    printDialog.hwndOwner = reinterpret_cast<HWND>(caller->windowHandle()->winId());

    // Calling...
    int result = PrintDlgEx(&printDialog);
    qDebug() << (result == E_INVALIDARG ? \"Invalid Argument\\n\" : \"Success\\n\");

    // It always is E_INVALIDARG

    // Cleanup
    if (printDialog.hDevMode)
       GlobalFree(printDialog.hDevMode);
    if (printDialog.hDevNames)
       GlobalFree(printDialog.hDevNames);
    if (printDialog.hDC)
       DeleteDC(printDialog.hDC);
}

平台：Windows 10，最新更新；
Qt 版本：5.12.7 或更高（因为在 VM 中我有 5.15.1）
我在 Qt 中运行的事实应该是无关紧要的，因为这都是 WIN API，超出了 c++ 版本 (11)

标签： c++ windows winapi printing printdialog

【解决方案1】：

如果我删除 PD_NONETWORKBUTTON 标志，我可以让你的示例工作。

请注意，虽然它记录在 PRINTDLGA 结构中，但它并未在 PRINTDLGEXA 中列出

【讨论】：