Question

从Obj-C typedef枚举中制作了一个Swift枚举声明，但现在我不知道如何在Swift中实现它。我看到了一个功能，但我不知道我用这两个案例来设置空闲/清醒？我如何标记暂停和恢复检测idleTimerDisabled？

//  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

你没有提供你翻译的Swift枚举的样子，所以我要定义一个似乎合适的。让我们说你的枚举看起来像这样：

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性的真实对象，因此如果将对象声明为枚举类型，则可以使用更短的点语法，如果您愿意：

currentState = .stateSampling

此处的实际Swift文档中提供了更多信息：

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

<强>更新

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

UIApplication.sharedApplication().idleTimerDisabled = false

typedef enum to Swift enum。如何用case来标记idleTimerDisabled的Pause和Resume检测？

1 个答案: