Question

所以我制作了一个自定义的UIButton并将其添加到代码中并在interfacebuiler中建立了连接。我想按钮作为开关工作，我该如何正确地做到这一点？我是iphone开发的初学者，这是我在暑假期间为本课程开设的一个学校项目，为下学期提供一个良好的开端。

所以，如果有人能帮助我理解如何以正确的方式做到这一点，并可能在代码中写评论。谢谢你的帮助。大卫H.

这是我的代码：

//
//  FlashlightViewController.h
//

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>

@interface FlashlightViewController : UIViewController {

    AVCaptureSession *torchSession;
    IBOutlet UIButton *button;
}

-(IBAction)pressButton:(id) sender;

@property (nonatomic, retain) AVCaptureSession *torchSession;
@property (nonatomic, retain) IBOutlet UIButton *button;

@end

这是.m文件

//
//  FlashlightViewController.m
//

#import "FlashlightViewController.h"

@implementation FlashlightViewController
@synthesize torchSession;
@synthesize button;


- (void)viewDidLoad {

    AVCaptureSession *session = [[AVCaptureSession alloc] init];

    [session beginConfiguration];

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    if ([device hasTorch] && [device hasFlash]){
        [device lockForConfiguration:nil];
        [device setTorchMode:AVCaptureTorchModeOn];
        [device setFlashMode:AVCaptureFlashModeOn];
        [device unlockForConfiguration];

        AVCaptureDeviceInput *flashInput = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil];
        if (flashInput){
            [session addInput:flashInput];
        }

        AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
        [session addOutput:output];
        [output release];
        [session commitConfiguration];

        [session startRunning];
    }

    [self setTorchSession:session];
    [session release];

    [super viewDidLoad];
}
- (void)viewDidUnload {
    self.button = nil;
}

- (void)dealloc {
    [TorchSession release];
    [button release];
    [super dealloc];
}
-(IBAction)pressButton : (id) sender{

}
@end

Answer 1

实际上你的问题是什么？有一个内置的UISwitch对象。如果你想创建一个自定义的，那么你可以跟踪一个bool标志并在按钮处理程序中切换它。

Answer 2

在@interface部分（.h）中，您还需要IBOutlet IBAction pressButton;。然后，在Interface Builder的检查器（出口部分）中，选择文件的所有者，并将pressButton:连接到UIButton的Touch Up Inside操作。

要切换手电筒状态，请将BOOL torchAlreadyOn;添加到@interface部分（.h）。然后，将您的viewDidLoad自定义代码移至pressButton方法。然后，在pressButton方法的末尾添加：

if (torchAlreadyOn) {
    torchAlreadyOn = NO;
}
else {
    torchAlreadyOn = YES;
}

然后，在将火炬状态设置为on的任何地方，将其括在if ... else语句中，该语句检查BOOL：

AVCaptureSession *session = [[AVCaptureSession alloc] init];

[session beginConfiguration];

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

if ([device hasTorch] && [device hasFlash]){
    [device lockForConfiguration:nil];

    if (torchAlreadyOn) {
        [device setTorchMode:AVCaptureTorchModeOn];
        [device setFlashMode:AVCaptureFlashModeOn];
    }
    else {
        [device setTorchMode:AVCaptureTorchModeOff];
        [device setFlashMode:AVCaptureFlashModeOff];
    }
    [device unlockForConfiguration];

    AVCaptureDeviceInput *flashInput = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil];
    if (flashInput){
        if (!torchAlreadyOn) {
            [session addInput:flashInput];
        }
        else {
            [session removeInput:flashInput];
        }
    }

    AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
    if (!torchAlreadyOn) {
        [session addOutput:output];
    }
    else {
        [session removeOutput:output];
    }
    [output release];
    [session commitConfiguration];

    [session startRunning];
}

[self setTorchSession:session];
[session release];

按下按钮启动应用程序

2 个答案: