如何清空UIPageViewController（删除里面的ViewControllers）

Question

设置一个PageViewController之后我想删除里面的视图控制器，把它留空。

我该怎么做？

我尝试了 // code omitted for brevity Server.withRouter() { case GET(p"/authenticatedEndpoint") => Action { request => request.headers.get(authHeader) match { case Some(authHeaderValue) => Results.Ok(expectedResult) case _ => Results.Forbidden } } } { implicit port => implicit val materializer = Play.current.materializer WsTestClient.withClient { client => val authenticatedClient: AuthenticatedClient = new AuthenticatedClient(client,filter) val result: String = Await.result(authenticatedClient.getStuff(), Duration.Inf) result must beEqualTo(expectedResult) } } } 方法在viewControllers param中传递setViewControllers:direction:animated:completion:或空数组，但它崩溃了。

我该怎么做？

Answer 1

如果>>>soup.find('a',{'class': 'follow_card'}).getText() u'Alex Key' 为setViewControllers:direction:animated:completion:参数的nil调用崩溃，请尝试将视图控制器设置为具有单个空视图控制器的数组。

viewControllers

Answer 2

String query = "CREATE TABLE " + TABLE + " (" +
                COLUMN_CONDUCTIVITY+ " FLOAT, " +
                COLUMN_OXYGEN+ " INTEGER, " +
                COLUMN_PH + " FLOAT, " +
                COLUMN_USERNAME+ " STRING PRIMARY KEY, " +
                COLUMN_PASSWORD + " TEXT," +
                COLUMN_MOISTURE+ " INTEGER "+
                ");";