部署的Qt5应用程序不打印或显示打印对话框 [英] Deployed Qt5 Application Doesn't Print or Show Print Dialog

问题描述

我遇到了Qt4到Qt5的麻烦。在我的应用程序中，当用户单击打印按钮时，应该发生两件事情，一种是将PDF写入磁盘（在新版本中仍然可以正常工作，因此我知道某些打印功能正常工作），另一种则是是一个QPrintDialog应该exec（），然后发送到连接的打印机。

当我从我的开发机器启动时，我看到对话框。应用程序在部署的机器上启动，但是QPrintDialog从不显示，文档不会打印。

我包含打印支持。

  QT + =核心gui网络webkitwidgets小部件printsupport 
  

我一直在使用Process Explorer来查看应用程序在我的开发机器上使用的DLL，我相信一切都存在。我的应用程序包包括：

• {myAppPath} \MyApp [MyApp.exe，Qt5PrintSupport.dll，...]


• {myAppPath} \plugins\printsupport\windowsprintersupport.dll


• {myAppPath} \plugins\imageformats [qgif.dll，qico.dll， qjpeg.dll，qmng.dll，qtga.dll，qtiff.dll，qwbmp.dll]

以下是相关的代码段：

  void PrintableForm :: printFile（）
 {
 //将PDF写入磁盘环境
 pdfCopy（）; 
 
 //纸张复制只适用于我的开发机器
 QPrinter paperPrinter; 
 QPrintDialog printDialog（& paperPrinter，this）; 
 
 if（printDialog.exec（）== QDialog :: Accepted）{
 view-> print（& paperPrinter）; 
} 
 this-> accept（）; 
} 
  

我的第一个想法是相关的DLL没有被发现是打印时间，这意味着我的应用程序文件系统不正确，但是我没有找到任何可以显示不同文件结构的东西。我在正确的轨道上还是有其他错误的设置？

解决方案

这是另一个经典的Windows / Qt5部署问题将错误的插件和插件的组合放在不正确的位置。通过使用环境变量QT_DEBUG_PLUGIN并将PROIG + = CONSOLE添加到我的PRO文件中，我可以看到在我的开发机器上的应用程序正在加载我没有发货的qminimal.dll。

我定义为{myAppPath} \的应用程序根是插件的根目录。因此，正确的文件结构是：

• {myAppPath} \MyApp [MyApp.exe，Qt5PrintSupport.dll，...] li>
  
• {myAppPath} \platforms [qwindows.dll，qminimal.dll]


• {myAppPath} \printsupport *


• {myAppPath} \imageformats *


• {myAppPath} \bearer *

I'm experiencing Qt4 to Qt5 troubles. In my application when the user clicks the print button two things should happen, one is that a PDF gets written to disk (which still works fine in the new version, so I know that some of the printing functions are working properly) and the other is that a QPrintDialog should exec() and then send to a connected printer.

I see the dialog when I launch from my development machine. The application launches on the deployed machine, but the QPrintDialog never shows and the document never prints.

I am including print support.

QT += core gui network webkitwidgets widgets printsupport

I have been using Process Explorer to see what DLLs the application uses on my development machine, and I believe that everything is present. My application bundle includes:

• {myAppPath}\MyApp[MyApp.exe, Qt5PrintSupport.dll, ...]
• {myAppPath}\plugins\printsupport\windowsprintersupport.dll
• {myAppPath}\plugins\imageformats[ qgif.dll, qico.dll,qjpeg.dll, qmng.dll, qtga.dll, qtiff.dll, qwbmp.dll ]

The following is the relevant code snippet:

void PrintableForm::printFile()
{
    //Writes the PDF to disk in every environment
    pdfCopy();

    //Paper Copy only works on my dev machine
    QPrinter paperPrinter;
    QPrintDialog printDialog(&paperPrinter,this);

    if( printDialog.exec() == QDialog::Accepted ) {
        view->print(&paperPrinter);
    }
    this->accept();
}

My first thought is that the relevant DLLs are not being found come print time, and that means that my application file system is incorrect, but I have not found anything that shows me a different file structure. Am I on the right track or is there something else wrong with this setup?

解决方案

This was another classic Windows/Qt5 deployment problem with a combination of missing plugins and plugins placed in incorrect places. By using the environmental variable QT_DEBUG_PLUGIN and adding CONFIG += CONSOLE to my PRO file I was able to see that on my development machine the application was loading qminimal.dll which I was not shipping.

The application root which I have defined as {myAppPath}\ is the root directory for plugins. Therefore the correct file structure is:

• {myAppPath}\MyApp[MyApp.exe, Qt5PrintSupport.dll, ...]
• {myAppPath}\platforms[qwindows.dll,qminimal.dll]
• {myAppPath}\printsupport*
• {myAppPath}\imageformats*
• {myAppPath}\bearer*

Thanks peppe for the lead.

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