PFQuery pinAllInBackground：block：永远不会完成 [英] PFQuery pinAllInBackground:block: never completes

问题描述

我有一个Parse应用程序，我想启用本地数据存储以进行缓存/脱机使用。在我的app委托中，我设置了 [Parse enableLocalDatastore]; 。

I have a Parse app and I want to enable local data store for caching/offline use. In my app delegate, I've set [Parse enableLocalDatastore];.

在我的查询中（到服务器） ），我正在进行正常查询，但是我在获取结果时固定结果：

In my query (to the server), I'm making a normal query, but I'm pinning the results upon fetch:

[followingsQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
    [PFObject pinAllInBackground:objects block:^(BOOL succeeded, NSError *error) {
        NSLog(@"er: %@", error);
    }];
    ... //rest of my handler
}];

然而，完成块（ NSLog（@er：％@） ，错误）; ）永远不会被调用。甚至没有错误。我到处都有断点。 pinAllInBackground：block：被调用，但它的完成处理程序从未被调用（我的应用程序已连续运行2分钟，它只固定100个对象，所以它应该是瞬时的）。我也试过 pinAllInBackground：withName：block：但没有区别。我试过 pinAll：并且它永远不会返回，阻塞调用线程（虽然它不消耗任何CPU）。我该如何解决这个问题？

However, the completion block (NSLog(@"er: %@", error);) is never called. Not even with an error. I've got breakpoints everywhere. pinAllInBackground:block: is called, but it's completion handler is never called (my app's been running for 2 minutes straight, it's pinning only 100 objects, so it should be instantaneous). I've also tried pinAllInBackground:withName:block: but no difference. I've tried pinAll: and it just never returns, blocking the calling thread (it doesn't consume any CPU though). How can I solve this problem?

推荐答案

这是我在运行嵌套在Parse中的另一个 inBackground -type方法中的inBackground -type方法。目前的解决方法是使用不同的调度方法，例如Grand Central Dispatch。

This is a known bug that I have experienced when running a nested inBackground-type method inside another inBackground-type method in Parse. The current workaround is to use a different dispatch method, such as Grand Central Dispatch.

试试这个：

[followingsQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
    dispatch_async(dispatch_get_main_queue(), ^{
        NSError *error = nil;
        id result = [PFObject pinAll:objects error:&error];
        if (error) {
            NSLog("error: %@", error);
        } 
    });
}];

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