ios - NSOperation 用户信息字典

Question

有没有办法让 userInfo NSDictionary 用于 NSOperation？

基本上我想为一个 NSOperation 分配一个 ID，稍后我想检查这个 ID 是否已经分配给一个 NSOperation

- (void)processSmthForID:(NSString *)someID {

    for (NSOperation * operation in self.precessQueue.operations) {

        if ([operation.userInfo[@"id"] isEqualToString:someID]) {
            // already doing this for this ID, no need to create another operation
            return;
        }

    }

    NSOperation * newOperation = ...
    newOperation.userInfo[@"id"] = someID;

    // enqueue and execute

}

Answer 1

NSOperation 意味着被子类化。只需设计您自己的子类。

The NSOperation class is an abstract class you use to encapsulate the code and data associated with a single task. Because it is abstract, you do not use this class directly but instead subclass or use one of the system-defined subclasses (NSInvocationOperation or NSBlockOperation) to perform the actual task.

read here

我同意@Daij-Djan 关于添加userInfo 属性的观点。
此属性可以作为 NSOperation 的扩展来实现(请参阅他的实现答案)。
但是，NSOperation 需要标识符是类的特化(您可以说新类是 IdentifiableOperation)