ios - 无法将 channel 保存到 PFInstallation (iOS)

Question

我正在尝试从 PFInstallation 添加/删除 channel ，但我不断收到相同的错误消息:

   Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Operation is invalid after previous operation.'

我的代码:

NSString * channel=[NSString stringWithFormat:@"%@%@%@", city, @"_", self.titleLabel.text];
PFInstallation *currentInstallation = [PFInstallation currentInstallation];
if([sender isOn]){
    [currentInstallation addUniqueObject:channel forKey:@"channels"];
} else{
    [currentInstallation removeObject:channel forKey:@"channels"];
}
[currentInstallation saveInBackground];

Answer 1

当 channels 为 nil 时，addUniqueObject 方法存在错误。你应该在它之前添加它。

if (currentInstallation.channels == nil)
{
    currentInstallation.channels = [[NSArray alloc] init];
}

此外，您应该使用 saveEventually 而不是 saveInBackGround。

这应该是SDK的一个bug。