dbms_sanya/python/plugins/FileManage/plugin.py

from .widgets.toolbar import SiweiToolbar
class Siwei:
    def __init__(self, iface):
        self.iface = iface
        self.toolbar = SiweiToolbar(self.iface)
        self.initGui()

    def initGui(self):
        self.iface.addToolBar(self.toolbar)


    def unload(self):
        """Unload from the QGIS interface"""
        self.toolbar.remove_dock()
        mw = self.iface.mainWindow()
        mw.removeToolBar(self.toolbar)
        self.toolbar.deleteLater()