def insertDomain(self, domain, indegree=0, outdegree=0):
		'''增加一个域名'''
		cur = self.conn.cursor()
		cur.execute("INSERT INTO Domains VALUES (NULL,?,?,?)", (domain, indegree, outdegree))
		# 写入到文件中
		self.conn.commit()
def draw_error(layout, message):
        lines = message.split("\n")
        box = layout.box()
        sub = box.row()
        sub.label(lines[0])
        sub.label(icon='ERROR')
        for l in lines[1:]:
            box.label(l)