Question

我试图获取当前登录用户正在关注的用户的数组，以便我可以在UICollectionView中显示它们。

我已经设置了一个活动类，其中包含指向用户的指针（在＆＃34; fromUser＆＃34;＆＃34; toUser＆＃34;列）。然后我尝试使用includeKey方法从User类获取每个用户的数据，这似乎不起作用。

这是我的代码：

 - (void)queryParseForFollowingUsers {

// Create query for users being followed by the current user
PFQuery *followingUsers = [PFQuery queryWithClassName:@"activity"];
[followingUsers whereKey:@"fromUser" equalTo: [PFUser currentUser]];
[followingUsers whereKey:@"activityType" equalTo:@"follow"];
[followingUsers includeKey:@"toUser"];

[followingUsers findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {

    // For each object from the query
    for (PFObject *followedUser in objects) {

        PFObject *userData = followedUser[@"toUser"];

        // Add object to the array of followedUsers

        [profilesArray addObject:userData];
        [profilesCollection reloadData];

    };

}];

NSLog(@"ARRAY RIGHT AFTER CREATION ######## %@", profilesArray);

}

奇怪的是，当我在块外部检查它的状态时，数组没有用任何内容更新，但是当我在循环中NSLog它的当前内容时它返回数据就好了。 profilesArray对象在.h文件中定义。

有没有人知道如何解决这个问题？我将不得不寻求任何帮助。

Answer 1

我破解了它：

 - (void)queryParseForFollowingUsers {

// Create query for users being followed by the current user
PFQuery *followingUsers = [PFQuery queryWithClassName:@"activity"];
[followingUsers whereKey:@"fromUser" equalTo: [PFUser currentUser]];
[followingUsers whereKey:@"activityType" equalTo:@"follow"];
[followingUsers includeKey:@"toUser"];

[followingUsers findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
    if (!error) {

        // Create an empty array for comparison
        NSArray *emptyArray = [[NSArray alloc] init];
        if ([objects isEqualToArray:emptyArray]) {
            [profilesArray removeAllObjects];

            // do something if there are no users followed by the current user

        } else {

            for (PFObject *followedUser in objects) {
                PFObject *userData = followedUser[@"toUser"];
                // Add object to the array of followedUsers
                [profilesArray addObject:userData];
                // Reload the collection view
                [self.profilesCollection reloadData];
            }
        }
    } else {
// Show the details of an error if it occurs
        [[[UIAlertView alloc] initWithTitle:@"An error occured" message:[NSString stringWithFormat:@"%@", [error userInfo]] delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil] show];
    }

}];

 }

使用Parse保存Query中的数据数组

1 个答案: