objective-c - typedef 枚举到 Swift 枚举。如何使用案例来标记idleTimerDisabled检测的Pause和Resume？

Question

从 Obj-C typedef 枚举中制定了 Swift 枚举声明，但现在我不知道如何在 Swift 中实现它。有人向我展示了一个功能，但我不知道在这两种情况下我会使用什么来设置空闲/唤醒？如何标记idleTimerDisabled检测的暂停和恢复？

//  ViewController.m   

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>  // import AVFoundation
#import "PulseDetector.h"
#import "Filter.h"

typedef NS_ENUM(NSUInteger, CURRENT_STATE) {
STATE_PAUSED,
STATE_SAMPLING
};

#define MIN_FRAMES_FOR_FILTER_TO_SETTLE 10

@interface ViewController ()<AVCaptureVideoDataOutputSampleBufferDelegate>



// other code here


 // !!!!!!! we're now sampling from the camera. My problem !!!!!!!!
self.currentState=STATE_SAMPLING;


// stop the app from sleeping
[UIApplication sharedApplication].idleTimerDisabled = YES;

// update our UI on a timer every 0.1 seconds
[NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(update) userInfo:nil repeats:YES];
}

-(void) stopCameraCapture {
[self.session stopRunning];
self.session=nil;
}

#pragma mark Pause and Resume of detection
-(void) pause {
if(self.currentState==STATE_PAUSED) return;

// switch off the torch
if([self.camera isTorchModeSupported:AVCaptureTorchModeOn]) {
    [self.camera lockForConfiguration:nil];
    self.camera.torchMode=AVCaptureTorchModeOff;
    [self.camera unlockForConfiguration];
}
self.currentState=STATE_PAUSED;
// let the application go to sleep if the phone is idle
[UIApplication sharedApplication].idleTimerDisabled = NO;
}

-(void) resume {
if(self.currentState!=STATE_PAUSED) return;

// switch on the torch
if([self.camera isTorchModeSupported:AVCaptureTorchModeOn]) {
    [self.camera lockForConfiguration:nil];
    self.camera.torchMode=AVCaptureTorchModeOn;
    [self.camera unlockForConfiguration];
}
self.currentState=STATE_SAMPLING;
// stop the app from sleeping
[UIApplication sharedApplication].idleTimerDisabled = YES;
}

快速翻译

// we're now sampling from the camera

enum CurrentState {
case statePaused
case stateSampling
}

var currentState = CurrentState.stateSampling

func setState(state: CurrentState){
            switch state
            {
            case .statePaused:
                // what goes here? Something like this?
            UIApplication sharedApplication.idleTimerDisabled = false
            case .stateSampling:
                // what goes here? Something like this?
            UIApplication sharedApplication.idleTimerDisabled = true
        }
        }

        // what goes here? Something like this?            
        currentState = CurrentState.stateSampling

Answer 1

您没有提供翻译后的 Swift 枚举，因此我将定义一个看起来合适的枚举。假设您的枚举如下所示:

enum CurrentState 
{
    case statePaused
    case stateSampling
}

如果您有 CurrentState 类型的变量，例如 currentState 字段，

你可以给它一个像这样的值:

currentState = CameraState.stateSampling

在 Swift 中，枚举被视为具有类型安全的真实对象，因此，如果将对象声明为枚举类型，您可以根据需要使用更短的点语法，如下所示:

currentState = .stateSampling

这里的实际 Swift 文档中有更多信息:

https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Enumerations.html

更新

您似乎只是询问如何设置 UIApplication sharedApplication 单例的 idleTimerDisabled 属性。你这样做:

UIApplication.sharedApplication().idleTimerDisabled = false