ios – ReactiveCocoa问题

概述我试图在我的项目中使用Reactive Cocoa来处理UITableView的填充. 当我加载数据时,如果没有,我想将tableView.backgroundView的隐藏属性设置为false.这是我到目前为止所拥有的： func loadData() { let dataSource = tableView.dataSource as! BlockedTableViewDataSour 我试图在我的项目中使用Reactive Cocoa来处理UItableVIEw的填充.

当我加载数据时,如果没有,我想将tableVIEw.backgroundVIEw的隐藏属性设置为false.这是我到目前为止所拥有的：

func loadData() {    let dataSource = tableVIEw.dataSource as! BlockedtableVIEwDataSource    let load = dataSource.load(currentUser) # RACSignal    load.map {        return (
func load(user: User) -> RACSignal {    return self.getBlocks(user).doNext {        self.blocks = 
2015-04-28 08:20:02.612 ohio[90547:2154845] *** Terminating app due to uncaught exception 'NSInternalinconsistencyException',reason: 'This query has an outstanding network connection. You have to wait until it's done.'*** First throw call stack:(    0   CoreFoundation                      0x000000010b840c65 __exceptionPreprocess + 165    1   libobjc.A.dylib                     0x000000010bc5dbb7 objc_exception_throw + 45    2   CoreFoundation                      0x000000010b840b9d +[NSException raise:format:] + 205    3   ohio                                0x0000000107facb1b -[PFquery checkIfCommandisRunning] + 77    4   ohio                                0x0000000107facb71 -[PFquery markAsRunning:] + 46    5   ohio                                0x0000000107fad105 -[PFquery _findobjectsAsync:after:] + 234    6   ohio                                0x0000000107faf0a0 -[PFquery findobjectsInBackgrounDWithBlock:] + 288    7   ohio                                0x0000000107d9532d _TFFE4ohioCSo7PFquery15rac_findobjectsFS0_FT_CSo9RACSignalU_FGSQPSo13RACSubscriber__GSQCSo13RACdisposable_ + 205    8   ohio                                0x0000000107d6639e _TTRXFo_oGSQPSo13RACSubscriber___oGSQCSo13RACdisposable__XFo_iGSQPS____iGSQS0___ + 30    9   ohio                                0x0000000107d944c1 _TPA__TTRXFo_oGSQPSo13RACSubscriber___oGSQCSo13RACdisposable__XFo_iGSQPS____iGSQS0___ + 81    10  ohio                                0x0000000107d663d4 _TTRXFo_iGSQPSo13RACSubscriber___iGSQCSo13RACdisposable__XFo_oGSQPS____oGSQS0___ + 36    11  ohio                                0x0000000107d66418 _TTRXFo_oGSQPSo13RACSubscriber___oGSQCSo13RACdisposable__XFdCb_dGSQPS____aGSQS0___ + 56    12  ohio                                0x0000000107eeacca __30-[RACDynamicSignal subscribe:]_block_invoke + 74    13  ohio                                0x0000000107f35b8e -[RACSubscriptionScheduler schedule:] + 478    14  ohio                                0x0000000107eeab9d -[RACDynamicSignal subscribe:] + 765    15  ohio                                0x0000000107f28f1d -[RACSignal(Subscription) subscribeNext:error:completed:] + 1133    16  ohio                                0x0000000107f004cc __32-[RACSignal(Operations) doNext:]_block_invoke + 396    17  ohio                                0x0000000107eeacca __30-[RACDynamicSignal subscribe:]_block_invoke + 74    18  ohio                                0x0000000107f35b8e -[RACSubscriptionScheduler schedule:] + 478    19  ohio                                0x0000000107eeab9d -[RACDynamicSignal subscribe:] + 765    20  ohio                                0x0000000107f2999e -[RACSignal(Subscription) subscribeError:completed:] + 766    21  ohio                                0x0000000107dc5fdb _TFC4ohio26BlockedtableVIEwController8loadDatafS0_FCS_4UserT_ + 3083    22  ohio                                0x0000000107dc6775 _TFC4ohio26BlockedtableVIEwController11vIEwDIDLoadfS0_FT_T_ + 501    23  ohio                                0x0000000107dc7702 _TToFC4ohio26BlockedtableVIEwController11vIEwDIDLoadfS0_FT_T_ + 34    24  UIKit                               0x000000010a142210 -[UIVIEwController loadVIEwIfrequired] + 738    25  UIKit                               0x000000010a14240e -[UIVIEwController vIEw] + 27    26  UIKit                               0x000000010a167297 -[UINavigationController _startCustomTransition:] + 633    27  UIKit                               0x000000010a1733bf -[UINavigationController _startDeferredTransitionIfNeeded:] + 386    28  UIKit                               0x000000010a173f0e -[UINavigationController __vIEwWillLayoutSubvIEws] + 43    29  UIKit                               0x000000010a2be715 -[UILayoutContainerVIEw layoutSubvIEws] + 202    30  UIKit                               0x000000011915093e -[UILayoutContainerVIEwAccessibility layoutSubvIEws] + 43    31  UIKit                               0x000000010a091a2b -[UIVIEw(CALayerDelegate) layoutSublayersOfLayer:] + 536    32  QuartzCore                          0x0000000109d12ec2 -[CALayer layoutSublayers] + 146    33  QuartzCore                          0x0000000109d076d6 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380    34  QuartzCore                          0x0000000109d07546 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24    35  QuartzCore                          0x0000000109c73886 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242    36  QuartzCore                          0x0000000109c74a3a _ZN2CA11Transaction6commitEv + 462    37  QuartzCore                          0x0000000109c750eb _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 89    38  CoreFoundation                      0x000000010b773ca7 __CFRUNLOOP_IS_CALliNG_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23    39  CoreFoundation                      0x000000010b773c00 __CFRunLoopDoObservers + 368    40  CoreFoundation                      0x000000010b769a33 __CFRunLoopRun + 1123    41  CoreFoundation                      0x000000010b769366 CFRunLoopRunspecific + 470    42  GraphiCSServices                    0x000000010cfc8a3e GSEventRunModal + 161    43  UIKit                               0x000000010a011900 UIApplicationMain + 1282    44  ohio                                0x0000000107d86df7 main + 135    45  libdyld.dylib                       0x000000010c3c1145 start + 1    46  ???                                 0x0000000000000001 0x0 + 1)libc++abi.dylib: terminating with uncaught exception of type NSException
 as! [Block]    }}private func getBlocks(fromUser: User) -> RACSignal {    let query = Block.query()!    query.whereKey("fromUser",equalTo: fromUser)    query.includeKey("toUser")    return query.rac_findobjects()}
 as! [AnyObject]).count > 0    }.startWith(true).distinctUntilChanged().setKeyPath("hIDden",onObject: tableVIEw.backgroundVIEw!)    load.subscribeError({ error in        println(error)    },completed: {        self.tableVIEw.reloadData()        self.refreshControl?.endRefreshing()    })}

然而,错误说我需要等待网络请求完成.我正在使用Parse来获取数据,但我认为我的ReactiveCocoa代码没有正确设置并导致此错误.如果我注释掉load.map …部分,表格将按预期填充.

如何以“反应方式”实现这一目标？

更新#1

这是dataSource的加载函数

let load = dataSource.load(currentUser).publish().autoconnect()

更新#2

解决方法 方法rac_findobjects()返回 cold signal.这意味着每次有人订阅此信号时,将重复其副作用(即执行底层网络请求).而且似乎PFquery doesn’t allow to send more than one simultaneous request,因此出现错误消息.

在您的情况下,您正在为加载信号进行两次订阅,因为调用setKeyPath也会创建一个.因此,网络请求会被执行两次,从而导致您发布的错误.

如链接的GitHub问题所示,您可以使用RACMulticastConnection确保副作用(网络请求)仅执行一次,无论有多少订阅者.例如：

总结

以上是内存溢出为你收集整理的ios – ReactiveCocoa问题全部内容，希望文章能够帮你解决ios – ReactiveCocoa问题所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。