windows: add extra link libraries for static qwindows plugin

README.md

@@ -76,6 +76,6 @@ Some C++ idioms that were difficult to project were omitted from the binding. Bu
 1. Build the necessary docker container for cross-compilation:
 	- `docker build -t miqt/win64-cross:latest -f win64-cross-go1.23-qt5.15-static.Dockerfile .`
 2. Build your application:
-	- `docker run --rm -v $(pwd):/src -w /src miqt/win64-cross:latest go build -buildvcs=false -ldflags '-s -w -H windowsgui'`
+	- `docker run --rm -v $(pwd):/src -w /src miqt/win64-cross:latest go build -buildvcs=false --tags=windowsqtstatic -ldflags '-s -w -H windowsgui'`
 
 For repeated builds, the compile speed can be improved if you also bind-mount the Docker container's `GOCACHE` directory: `-v $(pwd)/container-build-cache:/root/.cache/go-build`

qt/cflags_windowsqtstatic.cpp

@@ -0,0 +1,6 @@
+#ifdef MIQT_WINDOWSQTSTATIC
+
+#include <QtPlugin>
+Q_IMPORT_PLUGIN (QWindowsIntegrationPlugin);
+
+#endif

qt/cflags_windowsqtstatic.go

@@ -0,0 +1,17 @@
+//go:build windowsqtstatic
+// +build windowsqtstatic
+
+package qt
+
+// Some extra libraries should be linked to make a proper static build.
+// Otherwise, it can cause "No Qt platform plugin could be initialized" error.
+// @ref https://github.com/mappu/miqt/issues/25
+// @ref https://stackoverflow.com/a/16776116
+// @ref https://stackoverflow.com/a/58648193
+// @ref https://stackoverflow.com/a/57374635
+
+/*
+#cgo windowsqtstatic CXXFLAGS: -DMIQT_WINDOWSQTSTATIC
+#cgo LDFLAGS: -L/usr/lib/mxe/usr/x86_64-w64-mingw32.static/qt5/plugins/platforms -lqwindows -lQt5FontDatabaseSupport -lQt5EventDispatcherSupport -lQt5ThemeSupport -lQt5PlatformCompositorSupport -lQt5AccessibilitySupport -lQt5WindowsUIAutomationSupport -lwtsapi32
+*/
+import "C"