拍摄相片

<UIImagePickerControllerDelegate>

- (IBAction)takePicture:(id)sender
{
    // Make sure camera is available
    //UIImagePickerControllerSourceTypePhotoLibrary,访问设备上保存的所有照片
    //UIImagePickerControllerSourceTypeCamera,
    //UIImagePickerControllerSourceTypeSavedPhotosAlbum只能用于访问Camera                   Roll相册

    if ([UIImagePickerController
         isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] == NO)
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
                                                        message:@"Camera Unavailable"
                                                       delegate:self
                                              cancelButtonTitle:@"Cancel" 
                                              otherButtonTitles:nil, nil];
        [alert show];
        return;
    }
    if (self.imagePicker == nil)
    {
        self.imagePicker = [[UIImagePickerController alloc] init];
        self.imagePicker.delegate = self;
        self.imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
        self.imagePicker.allowsEditing = YES;//可编辑状态

    }
    [self presentViewController:self.imagePicker animated:YES completion:NULL];
}
        

//取回相片、更新图像视图，隐藏图像选取器

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage * image = [info objectForKey:UIImagePickerControllerEditedImage];//可编辑状态
    UIImageWriteToSavedPhotosAlbum (image, nil, nil , nil);//照片保存到相册中
    self.imageView.image = image;
    self.imageView.contentMode = UIViewContentModeScaleAspectFill;//充满整个视图
   
//self.imageView.contentMode = UIViewContentModeScaleAspectFit;//固定纵横比显示整张图片

   [self dismissViewControllerAnimated:YES completion:NULL];

}

//取消图片选择，隐藏图片选择器
- (void) imagePickerControllerDidCancel: (UIImagePickerController *) picker
{
    [self dismissViewControllerAnimated:YES completion:NULL];
}