对于dispatch多个异步操作后的同步方法,以前只看过dispatch_group_async,看看这个方法的说明: * @discussion * Submits a block to a dispatch queue and associates the block with the given * dispatch group. The dispatch group may be used to wait for the completion * of the blocks it ref
任务队列和异步接口的正确打开方式 什么是异步接口? Asynchronous Operations Certain types of operations might require processing of the request in an asynchronous manner (e.g. validating a bank account, processing an image, etc.) in order to avoid long delays on the client si