Error with UIImagePickerController

Question

I have this code for send images on tweet. When I try the app, the picker works well but it doesn't grab the image. What's wrong?

- (IBAction)sendImageTweet:(id)sender
{
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    picker.delegate = self;
    picker.allowsEditing = NO;
    [self presentModalViewController:picker animated:YES];
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    TWTweetComposeViewController *tweetViewController = [[TWTweetComposeViewController alloc] init];
    UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
    NSData *imageData = UIImagePNGRepresentation(image);
    [self dismissModalViewControllerAnimated:YES];
    [tweetViewController addImage:(UIImage *)imageData];
    [self presentModalViewController:tweetViewController animated:YES];
}

Answer 1

你应该使用常量，而不是NSString和密钥。

UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];