我在 void is it says undeclared identifier for sliderDidChange 的行上遇到了这个错误，有人可以帮我解决这个问题，我找不到任何答案。
H。文件
//
// LightViewController.h
// Flash Light
//
// Created by John Whitney on 12-07-27.
// Copyright (c) 2012 Perfect Programs. All rights reserved.
//
#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
@interface LightViewController : UIViewController {
IBOutlet UISlider *slider;
IBOutlet UISlider *theslider;
IBOutlet UISlider *customslider;
UIButton *onButton;
UIButton *offButton;
UIImageView *onView;
UIImageView *offView;
}
@property(nonatomic, strong) IBOutlet UIButton *onButton;
@property(nonatomic, strong) IBOutlet UIButton *offButton;
@property(nonatomic, strong) IBOutlet UIImageView *onView;
@property(nonatomic, strong) IBOutlet UIImageView *offView;
@property(nonatomic, readonly) float torchLevel;
-(void)sliderDidChange:(UISlider *)slider;
-(BOOL)setTorchModeOnWithLevel:(float)torchLevel error:(NSError **)outError;
-(BOOL)supportsAVCaptureSessionPreset:(NSString *)preset;
-(IBAction)torchOn:(id)sender;
-(IBAction)torchOff:(id)sender;
@end
m.文件
UISlider *localslider = [[UISlider alloc] initWithFrame:CGRectMake(20.0f, 20.0f, 280.0f, 40.0f)];
localslider.maximumValue = 1.0f;
localslider.minimumValue = 0.0f;
[localslider setContinuous:YES];
[localslider addTarget:self action:@selector(sliderDidChange:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:localslider];
-(void)sliderDidChange:(UISlider *)slider
{
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
[device lockForConfiguration:nil];
[device setTorchModeOnWithLevel:slider.value error:NULL];
[device unlockForConfiguration];
}
有人可以帮忙吗