iOS-将图片保存到照片相册中

UIImageWriteToSavedPhotosAlbum
Adds the specified image to the user’s Camera Roll album.

void UIImageWriteToSavedPhotosAlbum (
   UIImage  *image,
   id       completionTarget,
   SEL      completionSelector,
   void     *contextInfo
);
Parameters
image
The image to write to the Camera Roll album.
completionTarget
Optionally, the object whose selector should be called after the image has been written to the Camera Roll album.
completionSelector
The method selector, of the completionTarget object, to call. This optional method should conform to the following signature:
- (void)               image: (UIImage *) image
    didFinishSavingWithError: (NSError *) error
                 contextInfo: (void *) contextInfo;
contextInfo
An optional pointer to any context-specific data that you want passed to the completion selector.
Discussion
When used with an image picker controller, you would typically call this function within your imagePickerController:didFinishPickingMediaWithInfo: delegate method implementation.

The use of the completionTarget, completionSelector, and contextInfo parameters is optional and necessary only if you want to be notified asynchronously when the function finishes writing the image to the user’s Camera Roll or Saved Photos album. If you do not want to be notified, pass nil for these parameters.

When used on an iOS device without a camera, this method adds the image to the Saved Photos album rather than to the Camera Roll album.

Availability
Available in iOS 2.0 and later.
See Also
UISaveVideoAtPathToSavedPhotosAlbum
Declared In
UIImagePickerController.h