Obj-C 中异步方法的同步版本
在 Objective-C 中制作异步方法的同步版本的最佳方法是什么（对于 iOS，如果它很重要的话）？
假设您有一个具有这两种方法的类：
- (void) asyncDoSomething; // Starts an asynchronous task. Can't be changed.
- (void) onFinishDoSomething; // Called when the task is finished
您将如何实现一个直到任务完成才返回的同步 doSomething ？
What's the best way to make a synchronous version of an asynchronous method in Objective-C (for iOS, in case it matters)?
Say you have a class with these two methods:
- (void) asyncDoSomething; // Starts an asynchronous task. Can't be changed.
- (void) onFinishDoSomething; // Called when the task is finished
How would you implement a synchronous doSomething that does not return until the task is finished?
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（2）
好的，所以您可以声明一个全局布尔值，它会告诉您继续或等待，就在调用
- (void)asyncDoSomething;方法之前，您将BOOL wait设置为 < code>YES 并在等待响应的方法之后，在异步回调
- (void)onFinishDoSomething;中，将布尔值设置为NO;这样，您的方法仍然被称为异步，但后面的代码不会在响应之前执行。它会像同步一样等待。
Ok, so you can declare a global boolean that will tell you to continue or wait, just before calling your
- (void)asyncDoSomething;method you set yourBOOL waittoYESand after the method you doto wait for your response, and in you async callback
- (void)onFinishDoSomething;you set your boolean toNO;This way, your method is still called asynchronous but the code after is not executed before the response. It will wait like if it was synchronous.
进入 asyncDoSomething 实现并删除 NSThread/NSOperation/callback 代码。
Go into the asyncDoSomething implementation and remove the NSThread/NSOperation/callback code.