使用CloudKit时"无法发送有效签名"错误

Question

任何人都知道可能导致此错误的原因在下面的查询块中返回:

<CKError 0x7f8d5ba27a10: "Internal Error" (1/4000); "Couldn't send a valid signature">

这是我的代码片段:

CKContainer *container = [CKContainer defaultContainer];
CKDatabase *publicDatabase = [container publicCloudDatabase];

//CKDatabase *publicDatabase = [[CKContainer containerWithIdentifier:container] publicCloudDatabase];

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"doctorName = %@", @"Dr. Harry White"];
CKQuery *query = [[CKQuery alloc] initWithRecordType:@"WellnessTest" predicate:predicate];

[publicDatabase performQuery:query inZoneWithID:nil completionHandler:^(NSArray *results, NSError *error)
{
    if (error)
    {
        // Error handling for failed fetch from public database
        NSLog(@"ERROR: %@", error.description);
    }
    else
    {
        // Display the fetched records
        NSLog(@"Results: %@", results.description);
    }
}];

Answer 1

在iPhone/iPad模拟器上,转到"设置">"iCloud",然后使用Apple ID登录.