在非 GUI 环境中使用 QPainter
Using QPainter in non-GUI environment
在非 GUI 环境中使用 QPainter 可能会有用 f.e。在（网络）服务器上生成 PDF。
但是 QPainter 依赖于 QGuiApplication，这会导致运行时错误：
qt.qpa.screen: QXcbConnection: Could not connect to display
Could not connect to any X display.
如何在非 GUI 环境中使用 QPainter（没有可用的输出屏幕）？
您应该使用以下命令行参数启动您的应用程序：-platform minimal:
minimal is provided as an examples for developers who want to write their own platform plugins. However, you can use the plugin to run GUI applications in environments without a GUI, such as servers.
注意 -platform offscreen 似乎需要支持字体，即绘制文本，否则会显示黑色方块而不是实际文本。
进一步阅读和参考
- Getting font metrics without GUI (console mode)
- https://lists.qt-project.org/pipermail/interest/2016-June/022942.html
- QPainter.drawText() SIGSEGV Segmentation fault
- What is the use of various Qt platform plugins?
在非 GUI 环境中使用 QPainter 可能会有用 f.e。在（网络）服务器上生成 PDF。
但是 QPainter 依赖于 QGuiApplication，这会导致运行时错误：
qt.qpa.screen: QXcbConnection: Could not connect to display Could not connect to any X display.
如何在非 GUI 环境中使用 QPainter（没有可用的输出屏幕）？
您应该使用以下命令行参数启动您的应用程序：-platform minimal:
minimal is provided as an examples for developers who want to write their own platform plugins. However, you can use the plugin to run GUI applications in environments without a GUI, such as servers.
注意 -platform offscreen 似乎需要支持字体，即绘制文本，否则会显示黑色方块而不是实际文本。
进一步阅读和参考
- Getting font metrics without GUI (console mode)
- https://lists.qt-project.org/pipermail/interest/2016-June/022942.html
- QPainter.drawText() SIGSEGV Segmentation fault
- What is the use of various Qt platform plugins?