iOS 自定义UIImagePickerController

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iOS 自定义UIImagePickerController

系统自带UIImagePickerController的用法

调用方式

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UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
//sourceType = UIImagePickerControllerSourceTypeCamera; //照相机
//sourceType = UIImagePickerControllerSourceTypePhotoLibrary; //图片库
//sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; //保存的相片
if(self.picker == nil){
    self.picker = [[UIImagePickerController alloc] init];//初始化
    self.picker.delegate = self;
    self.picker.allowsEditing = NO;//设置可编辑
    self.picker.sourceType = sourceType;
}
   
[self presentViewController:self.picker animated:true completion:nil];

回调

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//当选择一张图片后进入这里
-(void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
    
    NSString *type = [info objectForKey:UIImagePickerControllerMediaType];
    
    //当选择的类型是图片
    if ([type isEqualToString:@"public.image"]){
        //先把图片转成NSData
        UIImage* image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
        image = [self fixOrientation:image];
        NSData *data;
        
        data = UIImageJPEGRepresentation(image, 0.5);
        
        NSString * md5Str = [data MD5HexDigest];
        
        //图片保存的路径
        //这里将图片放在沙盒的documents文件夹中
        NSString * DocumentsPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
        NSString * fileName = [NSString stringWithFormat:@"%@.jpg",md5Str];
        //得到选择后沙盒中图片的完整路径
        _filePath = [[NSString alloc]initWithFormat:@"%@/%@",DocumentsPath,fileName];
        //文件管理器
        NSFileManager *fileManager = [NSFileManager defaultManager];
        
        //把刚刚图片转换的data对象拷贝至沙盒中 并保存为image.jpg
        [fileManager createDirectoryAtPath:DocumentsPath withIntermediateDirectories:YES attributes:nil error:nil];
        [fileManager createFileAtPath:_filePath contents:data attributes:nil];
        NSLog(@"文件的路径为：%@",_filePath);
    } 
    
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    NSLog(@"您取消了选择图片");
    [self.picker dismissViewControllerAnimated:true completion:^{
        
    }];
}

拍照后的图片90度旋转的解决方法

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-(UIImage *)fixOrientation:(UIImage *)aImage {
    // No-op if the orientation is already correct
    if (aImage.imageOrientation == UIImageOrientationUp)
        return aImage;
    // We need to calculate the proper transformation to make the image upright.
    // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
    CGAffineTransform transform = CGAffineTransformIdentity;
    switch (aImage.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        default:
            break;
    }
    switch (aImage.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, aImage.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        default:
            break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,
                                             CGImageGetBitsPerComponent(aImage.CGImage), 0,
                                             CGImageGetColorSpace(aImage.CGImage),
                                             CGImageGetBitmapInfo(aImage.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (aImage.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);
            break;
        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);
            break;
    }
    
    // And now we just create a new UIImage from the drawing context
    CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
    UIImage *img = [UIImage imageWithCGImage:cgimg];
    CGContextRelease(ctx);
    CGImageRelease(cgimg);
    return img;
}

自定义相机拍照视图

定义变量

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//捕获设备，通常是前置摄像头，后置摄像头，麦克风（音频输入）
@property (nonatomic, strong) AVCaptureDevice *device;

//AVCaptureDeviceInput 代表输入设备，他使用AVCaptureDevice 来初始化
@property (nonatomic, strong) AVCaptureDeviceInput *input;

//输出图片
@property (nonatomic ,strong) AVCaptureStillImageOutput *imageOutput;

//session：由他把输入输出结合在一起，并开始启动捕获设备（摄像头）
@property (nonatomic, strong) AVCaptureSession *session;

//图像预览层，实时显示捕获的图像
@property (nonatomic ,strong) AVCaptureVideoPreviewLayer *previewLayer;

@property (weak, nonatomic) IBOutlet UIView *previewView;
@property (weak, nonatomic) IBOutlet UIImageView *showImageView;

设置相机

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- (void)cameraDistrict{
    //    AVCaptureDevicePositionBack  后置摄像头
    //    AVCaptureDevicePositionFront 前置摄像头
    self.device = [self cameraWithPosition:AVCaptureDevicePositionBack];
    self.input = [[AVCaptureDeviceInput alloc] initWithDevice:self.device error:nil];
    
    self.imageOutput = [[AVCaptureStillImageOutput alloc] init];
    
    self.session = [[AVCaptureSession alloc] init];
    //     拿到的图像的大小可以自行设定
    //    AVCaptureSessionPreset320x240
    //    AVCaptureSessionPreset352x288
    //    AVCaptureSessionPreset640x480
    //    AVCaptureSessionPreset960x540
    //    AVCaptureSessionPreset1280x720
    //    AVCaptureSessionPreset1920x1080
    //    AVCaptureSessionPreset3840x2160
    self.session.sessionPreset = AVCaptureSessionPreset640x480;
    //输入输出设备结合
    if ([self.session canAddInput:self.input]) {
        [self.session addInput:self.input];
    }
    if ([self.session canAddOutput:self.imageOutput]) {
        [self.session addOutput:self.imageOutput];
    }
    //预览层的生成
    self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
    self.previewLayer.frame = self.previewView.frame;
    self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    [self.previewView.layer addSublayer:self.previewLayer];
    //设备取景开始
    [self.session startRunning];
    if ([_device lockForConfiguration:nil]) {
        //自动闪光灯，
        if ([_device isFlashModeSupported:AVCaptureFlashModeAuto]) {
            [_device setFlashMode:AVCaptureFlashModeAuto];
        }
        //自动白平衡,但是好像一直都进不去
        if ([_device isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeAutoWhiteBalance]) {
            [_device setWhiteBalanceMode:AVCaptureWhiteBalanceModeAutoWhiteBalance];
        }
        [_device unlockForConfiguration];
    }
    
}

- (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition)position{
    NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    for ( AVCaptureDevice *device in devices )
        if ( device.position == position ){
            return device;
        }
    return nil;
}

获取相机图片

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- (void)photoBtnDidClick{
    AVCaptureConnection *conntion = [self.imageOutput connectionWithMediaType:AVMediaTypeVideo];
    if (!conntion) {
        NSLog(@"拍照失败!");
        return;
    }
    [self.imageOutput captureStillImageAsynchronouslyFromConnection:conntion completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
        if (imageDataSampleBuffer == nil) {
            return ;
        }
        NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
        self.showImageView.image = [UIImage imageWithData:imageData];
        self.showImageView.hidden = false;
        [self.session stopRunning];
    }];
}

保存照片到相册

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#pragma - 保存至相册
- (void)saveImageToPhotoAlbum:(UIImage*)savedImage{
    UIImageWriteToSavedPhotosAlbum(savedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
    
}
 // 指定回调方法
- (void)image: (UIImage *) image didFinishSavingWithError: (NSError *) error contextInfo: (void *) contextInfo{
    NSString *msg = nil ;
    if(error != NULL){
        msg = @"保存图片失败" ;
    }else{
        msg = @"保存图片成功" ;
    }
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"保存图片结果提示"
                                                    message:msg
                                                   delegate:self
                                          cancelButtonTitle:@"确定"
                                          otherButtonTitles:nil];
    [alert show];
}

前后置摄像头的切换

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- (void)changeCamera{
     NSUInteger cameraCount = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo] count];
     if (cameraCount > 1) {
         NSError *error;
         //给摄像头的切换添加翻转动画
         CATransition *animation = [CATransition animation];
         animation.duration = .5f;
         animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
         animation.type = @"oglFlip";
         
         AVCaptureDevice *newCamera = nil;
         AVCaptureDeviceInput *newInput = nil;
         //拿到另外一个摄像头位置
         AVCaptureDevicePosition position = [[_input device] position];
         if (position == AVCaptureDevicePositionFront){
             newCamera = [self cameraWithPosition:AVCaptureDevicePositionBack];
             animation.subtype = kCATransitionFromLeft;//动画翻转方向
         }
         else {
             newCamera = [self cameraWithPosition:AVCaptureDevicePositionFront];
             animation.subtype = kCATransitionFromRight;//动画翻转方向
         }
         //生成新的输入
         newInput = [AVCaptureDeviceInput deviceInputWithDevice:newCamera error:nil];
         [self.previewLayer addAnimation:animation forKey:nil];
         if (newInput != nil) {
             [self.session beginConfiguration];
             [self.session removeInput:self.input];
             if ([self.session canAddInput:newInput]) {
                 [self.session addInput:newInput];
                 self.input = newInput;
                 
             } else {
                 [self.session addInput:self.input];
             }
             [self.session commitConfiguration];
             
         } else if (error) {
             NSLog(@"toggle carema failed, error = %@", error);
         }
     }
 }

对焦设置

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//AVCaptureFlashMode  闪光灯
//AVCaptureFocusMode  对焦
//AVCaptureExposureMode  曝光
//AVCaptureWhiteBalanceMode  白平衡
//闪光灯和白平衡可以在生成相机时候设置
//曝光要根据对焦点的光线状况而决定,所以和对焦一块写
//point为点击的位置
- (void)focusAtPoint:(CGPoint)point{
 CGSize size = self.view.bounds.size;
 CGPoint focusPoint = CGPointMake( point.y /size.height ,1-point.x/size.width );
 NSError *error;
 if ([self.device lockForConfiguration:&error]) {
     //对焦模式和对焦点
     if ([self.device isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {
         [self.device setFocusPointOfInterest:focusPoint];
         [self.device setFocusMode:AVCaptureFocusModeAutoFocus];
     }
     //曝光模式和曝光点
     if ([self.device isExposureModeSupported:AVCaptureExposureModeAutoExpose ]) {
         [self.device setExposurePointOfInterest:focusPoint];
         [self.device setExposureMode:AVCaptureExposureModeAutoExpose];
     }
     
     [self.device unlockForConfiguration];
         //设置对焦动画
//         _focusView.center = point;
//         _focusView.hidden = NO;
//         [UIView animateWithDuration:0.3 animations:^{
//             _focusView.transform = CGAffineTransformMakeScale(1.25, 1.25);
//         }completion:^(BOOL finished) {
//             [UIView animateWithDuration:0.5 animations:^{
//                 _focusView.transform = CGAffineTransformIdentity;
//             } completion:^(BOOL finished) {
//                 _focusView.hidden = YES;
//             }];
//         }];
     }
}

遇到的一些坑和解决办法

前后置摄像头的切换

　　前后值不能切换，各种尝试找了半天没找到有原因。后来发现我在设置图片尺寸的时候设置为1080P[self.session canSetSessionPreset: AVCaptureSessionPreset1920x1080]，前置摄像头并不支持这么大的尺寸，所以就不能切换前置摄像头。
　　我验证了下 前置摄像头最高支持720P,720P以内可自由切换。
当然也可以在前后置摄像头切换的时候，根据前后摄像头来设置不同的尺寸，这里不在赘述。

焦点位置

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CGPoint focusPoint = CGPointMake( point.y /size.height ,1-point.x/size.width );

setExposurePointOfInterest：focusPoint 函数后面Point取值范围是取景框左上角（0，0）到取景框右下角（1，1）之间。官方是这么写的： 

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The value of this property is a CGPoint that determines the receiver's focus point of interest, if it has one. A value of (0,0) indicates that the camera should focus on the top left corner of the image, while a value of (1,1) indicates that it should focus on the bottom right. The default value is (0.5,0.5).  
我也试了按这个来但位置就是不对，只能按上面的写法才可以。前面是点击位置的y/PreviewLayer的高度，后面是1-点击位置的x/PreviewLayer的宽度

对焦和曝光

我在设置对焦是 先设置了模式setFocusMode，后设置对焦位置，就会导致很奇怪的现象，对焦位置是你上次点击的位置。所以一定要先设置位置，再设置对焦模式。
曝光同上