Taking Photos with the Camera（拍照）

1。导入库，实现协议

   #import <MobileCoreServices/MobileCoreServices.h>

   <UIImagePickerControllerDelegate, UINavigationControllerDelegate>

e.g.

- (BOOL) cameraSupportsMedia:(NSString *)paramMediaType sourceType:(UIImagePickerControllerSourceType)paramSourceType{

    __block BOOL result = NO;   

    if ([paramMediaType length] == 0){

        NSLog(@"Media type is empty.");

        return NO;

    }  

    //获取本机中符合指定资源的所有媒体类型，以便后续判定是否支持

    NSArray *availableMediaTypes =  [UIImagePickerController  availableMediaTypesForSourceType:paramSourceType];   

    [availableMediaTypes  enumerateObjectsUsingBlock:

         ^(id obj, NSUInteger idx, BOOL *stop) {       

         NSString *mediaType = (NSString *)obj;

         if ([mediaType isEqualToString:paramMediaType]){

             result = YES;

             *stop= YES;

         }        

     }];    

    return result;    

}

//摄像头是否支持拍照 

- (BOOL) doesCameraSupportTakingPhotos{  

    //KUTTypeImage : 静态图片  

    return [self cameraSupportsMedia:(__bridge NSString *)kUTTypeImage  sourceType:UIImagePickerControllerSourceTypeCamera];    

}

//是否可用摄像头

- (BOOL) isCameraAvailable{    

    return[UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera];   

}

//delegate:完成选择，注意这里的视频数据或是相片数据并未被保存（到机子的相册中）

- (void)  imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {  

    NSLog(@"Picker returned successfully.");  

    NSLog(@"infoOfPickedMedia:%@", info); //info:包含了挑选的媒体信息   

    NSString  *mediaType = info[UIImagePickerControllerMediaType];   

    if ([mediaType isEqualToString:(__bridge NSString *)kUTTypeMovie]){ //挑选的是视频 

        NSURL *urlOfVideo = info[UIImagePickerControllerMediaURL];

        NSLog(@"Video URL = %@", urlOfVideo);

    } 

    else if ([mediaType isEqualToString:(__bridge NSString *)kUTTypeImage]){ //挑选的是相片       

        NSDictionary *metadata = info[UIImagePickerControllerMediaMetadata]; //metadata只针对images

        UIImage *theImage = info[UIImagePickerControllerOriginalImage];        

        NSLog(@"Image Metadata = %@", metadata);

        NSLog(@"Image = %@", theImage);       

    }   

   [picker dismissViewControllerAnimated:YES completion:nil];  

}

//delegate 取消选择

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{

    NSLog(@"Picker was cancelled");

    [picker dismissViewControllerAnimated:YES completion:nil];   

}

- (void)actionDisplayPickerController {

    if ([self isCameraAvailable] && [self doesCameraSupportTakingPhotos]){

        UIImagePickerController *controller =  [[UIImagePickerController alloc] init];      

        controller.sourceType = UIImagePickerControllerSourceTypeCamera; //从照相机获取资源，如拍照，摄像等   

        //mediaType:KUTTypeImage / KUTTypeMovie 这里决定了出现的模式窗口imagePickerController是进行摄像还是进行照相

        NSString *requiredMediaType = (__bridge NSString *)kUTTypeImage; 

        controller.mediaTypes = [[NSArray alloc] initWithObjects:requiredMediaType, nil];        

        controller.allowsEditing = YES;

        controller.delegate = self;       

       [self presentViewController:controller animated:YES completion:nil];       

    } else {

        NSLog(@"Camera is not available.");

    }   

}

postscript:

    didFinishPickingMediaWithInfo中的字典集info包含了所获取资源的各项属性（以下是可访问的key）

    对于images（KUTTypeImage）:默认获取到的相片不会被保存

       UIImagePickerControllerMediaMetadata:元数据（NSDictionary）

       UIImagePickerControllerOriginalImage:获取到的未编辑的原始图

       UIImagePickerControllerCropRect:被裁剪的尺寸（若可修改的话 allowsEditing = YES）

       UIImagePickerControllerEditedImage:编辑后的图

    对于videos（KUTTypeMovie）:

       UIImagePickerControllerMediaURL:获取到video的URL