利用 QPrinter 和html 生成 pdf文档
其中用html语句有显示图片的语句
但只能显示png格式的图片，不能显示jpg格式图片。
经过排查:语法，文件路径等都正确，最终在stack overflow 中找到 原因：在执行程序中没有安装 jpg图形格式的plugin
https://stackoverflow.com/questions/14878670/qt-does-not-load-jpg-just-png
{
Your executable is missing the jpg plugin. Optional means, that if your executable doesn't find the plugins (dlls) it will start, but without loading these image formats. It is the same with a lot of qt features (fe: slqdrivers)
You will find the folder "imageformats" in C:Qt4.8.4plugins (replace your installation dir and version), copy it to your executable path and it will show jpgs.
Probably, some environmental variables of your colleagues differ a bit from yours.
Take care with Qt plugins and the distribution of your application.
}
同样 在qlistwiget中以图标方式显示图片时也不能显示jpg格式文件。也用上面的方式解决。