Swift中C的Block的调用

最新推荐文章于 2021-08-03 09:51:06 发布

转载最新推荐文章于 2021-08-03 09:51:06 发布 · 750 阅读

本文介绍如何使用FSEvents API来监控文件系统的更改事件。通过创建事件流并指定回调函数，可以实现实时监听文件夹内文件的变化情况，如创建、删除或修改等。

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init () {

    let allocator: CFAllocator? = kCFAllocatorDefault

    // Create FSEventStream and return valid FSEventStreamRef
    // Alias FSEventStreamCallback - CFunction
    typealias FSEventStreamCallback = @convention(c) (ConstFSEventStreamRef, UnsafeMutablePointer<Void>, Int, UnsafeMutablePointer<Void>, UnsafePointer<FSEventStreamEventFlags>, UnsafePointer<FSEventStreamEventId>) -> Void
    let callback: FSEventStreamCallback = {
        (streamRef, clientCallBackInfo, numEvents, eventPaths, eventFlags, eventIds) -> Void in
        print ("changed")
        // handle file event
    }


    let context: UnsafeMutablePointer<FSEventStreamContext> = nil
    let pathsToWatch: CFArray = [NSHomeDirectory() + "/Dir"]
    let sinceWhen: FSEventStreamEventId = UInt64(kFSEventStreamEventIdSinceNow)
    let latency: CFTimeInterval = 1.0
    let flags: FSEventStreamCreateFlags = UInt32(kFSEventStreamCreateFlagNone)

    let eventStream = FSEventStreamCreate(
        allocator,
        callback,
        context,
        pathsToWatch,
        sinceWhen,
        latency,
        flags
    )

    FSEventStreamScheduleWithRunLoop(eventStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode)
    FSEventStreamStart(eventStream)

}