用于保存图片到文档

- (void)saveImage:(UIImage *)image forPerson:(NSString *)fullName  {
    //  Make file name first
    NSString *filename = [fullName stringByAppendingString:@".png"]; // or .jpg

    //  Get the path of the app documents directory
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    //  Append the filename and get the full image path
    NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:filename];

    //  Now convert the image to PNG/JPEG and write it to the image path
    NSData *imageData = UIImagePNGRepresentation(image);
    [imageData writeToFile:savedImagePath atomically:NO];   

    //  Here you save the savedImagePath to your DB
    ...
}

所以，你以后可以通过

- (UIImage *)loadImage:(NSString *)filePath  {
    return [UIImage imageWithContentsOfFile:filePath];
}