- (IBAction)takePictureButtonClick:(id)sender{
    //检查相机模式是否可用
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        NSLog(@"sorry, no camera or camera is unavailable.");
        return;
    }
    //获得相机模式下支持的媒体类型
    NSArray* availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
    BOOL canTakePicture = NO;
    for (NSString* mediaType in availableMediaTypes) {
        if ([mediaType isEqualToString:[NSString stringWithCString:kUTTypeImage encoding:NSUTF8StringEncoding]]) {
            //支持拍照
            canTakePicture = YES;
            break;
        }
    }
    //检查是否支持拍照
    if (!canTakePicture) {
        NSLog(@"sorry, taking picture is not supported.");
        return;
    }
    //创建图像选取控制器
    UIImagePickerController* imagePickerController = [[UIImagePickerController alloc] init];
    //设置图像选取控制器的来源模式为相机模式
    imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
    //设置图像选取控制器的类型为静态图像
    imagePickerController.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeImage, nil];
    //允许用户进行编辑
    imagePickerController.allowsEditing = YES;
    //设置委托对象
    imagePickerController.delegate = self;
    //以模视图控制器的形式显示
    [self presentModalViewController:imagePickerController animated:YES];
}

- (IBAction)captureVideoButtonClick:(id)sender{
    //检查相机模式是否可用
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        NSLog(@"sorry, no camera or camera is unavailable!!!");
        return;
    }
    //获得相机模式下支持的媒体类型
    NSArray* availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
    BOOL canTakeVideo = NO;
    for (NSString* mediaType in availableMediaTypes) {
        if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
            //支持摄像
            canTakeVideo = YES;
            break;
        }
    }
    //检查是否支持摄像
    if (!canTakeVideo) {
        NSLog(@"sorry, capturing video is not supported.!!!");
        return;
    }
    //创建图像选取控制器
    UIImagePickerController* imagePickerController = [[UIImagePickerController alloc] init];
    //设置图像选取控制器的来源模式为相机模式
    imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
    //设置图像选取控制器的类型为动态图像
    imagePickerController.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeMovie, nil];
    //设置摄像图像品质
    imagePickerController.videoQuality = UIImagePickerControllerQualityTypeHigh;
    //设置最长摄像时间
    imagePickerController.videoMaximumDuration = 30;
    //允许用户进行编辑
    imagePickerController.allowsEditing = YES;
    //设置委托对象
    imagePickerController.delegate = self;
    //以模式视图控制器的形式显示
    [self presentModalViewController:imagePickerController animated:YES];
    
}

- (void)image:(UIImage*)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo{
    if (!error) {
        NSLog(@"picture saved with no error.");
    }
    else
    {
        NSLog(@"error occured while saving the picture%@", error);
    }
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
    //打印出字典中的内容
    NSLog(@"get the media info: %@", info);
    //获取媒体类型
    NSString* mediaType = [info objectForKey:UIImagePickerControllerMediaType];
    //判断是静态图像还是视频
    if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
        //获取用户编辑之后的图像
        UIImage* editedImage = [info objectForKey:UIImagePickerControllerEditedImage];
        //将该图像保存到媒体库中
        UIImageWriteToSavedPhotosAlbum(editedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
    }else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])
    {
        //获取视频文件的url
        NSURL* mediaURL = [info objectForKey:UIImagePickerControllerMediaURL];
        //创建ALAssetsLibrary对象并将视频保存到媒体库
        ALAssetsLibrary* assetsLibrary = [[ALAssetsLibrary alloc] init];
        [assetsLibrary writeVideoAtPathToSavedPhotosAlbum:mediaURL completionBlock:^(NSURL *assetURL, NSError *error) {
            if (!error) {
                NSLog(@"captured video saved with no error.");
            }else
            {
                NSLog(@"error occured while saving the video:%@", error);
            }
        }];
    }
    [picker dismissModalViewControllerAnimated:YES];
    
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [picker dismissModalViewControllerAnimated:YES];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}