Devtool can't copy directory if folder contains files, like .txt

  When I created a installer.exe and I need copy a folder that contains "sample.txt" to "D:
", I got this error "Can't create D:\\sample
sample.txt". So I used devtool.exe to test this, the command line: "devtool.exe operation DO,CopyDirectory,sample,D:
". The folder what name is sample contains a "sample.txt" and a subdirectory. Similarly, it shows "Can't create D:\\sample
sample.txt for output".

  Then, I downloaded source code qt-installer-framework-4.0.1.zip. I found "sourcecode\\src\\libs\\installer
[copydirectoryoperation.cpp|https://invent.kde.org/qt/installer-framework/installer-framework/-/blob/master/src/libs/installer/copydirectoryoperation.cpp]", some code below:

 } else {
            const QString absolutePath = targetDir.absoluteFilePath(relativePath);
            ...
            QFile file(sourceDir.absoluteFilePath(itemName));
            if (!file.copy(absolutePath)) {
                qDebug() << "Cannot copy file"
                         << QDir::toNativeSeparators(sourceDir.absoluteFilePath(itemName))
                         << QDir::toNativeSeparators(targetDir.absoluteFilePath(relativePath))
                         << file.errorString();
            }
 }

Yeah, I thought I got it. When I copy a directory contains some files not only subdirectory, it always copy files firstly, then copy subdirectory. If target directory doesn't exist, it will failed. Because QFile::copy(const QString &name) can't copy a file if the path of this file doesn't exist.

  Finally, I add some code below, it can work normally.

  const QString absolutePath = targetDir.absoluteFilePath(relativePath);
  ...
+ if (!QDir(QFileInfo(absolutePath).path()).exists())
+         targetDir.mkpath(QFileInfo(absolutePath).path());
  QFile file(sourceDir.absoluteFilePath(itemName));

    I also solved my question by another way. I changed my scripts before copy directory, like this:

  component.createOperations();
  if (systemInfo.productType === "windows") { 
+     component.addOperation ( "Mkdir","D:\\sample" ); 
      component.addOperation ( "CopyDirectory","@InstallerDirPath@\\sample","D:\\",    "forceOverwrite" );
  }