NSMutableArray中的多个图像

Question

I am saving images from the camera in an NSMutableArray. When I add one picture, the picture is added to the array. But, the problem is that when I take another picture, the first picture is replaced by the second one. I want to save all of the pictures taken by the camera.

- (IBAction)takePhoto {
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.allowsEditing = YES;
    picker.sourceType = UIImagePickerControllerSourceTypeCamera;

    [self presentViewController:picker animated:YES completion:NULL];
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    UIImage *cameraImage = info[UIImagePickerControllerEditedImage];
    self.tempView.image = cameraImage;
    camImages = [NSMutableArray arrayWithCapacity:10];
    [camImages addObject:self.tempView.image];
    //self.chosenImages=camImages;
    NSLog(@"the image is=%@",camImages);
    [picker dismissViewControllerAnimated:YES completion:NULL];
}

Answer 1

Take away camImages = [NSMutableArray arrayWithCapacity:10]; and put it in viewDidLoad.

EDIT: Use this instead:

UIImage *cameraImage = info[UIImagePickerControllerEditedImage];
self.tempView.image = cameraImage;

if(!camImages)camImages = [[NSMutableArray alloc]init];

camImages = [NSMutableArray arrayWithCapacity:10];
[camImages addObject:self.tempView.image];
//self.chosenImages=camImages;
NSLog(@"the image is=%@",camImages);
[picker dismissViewControllerAnimated:YES completion:NULL];

Answer 2

The problem it's because [NSMutableArray arrayWithCapacity:10]; actually allocates a new position in memory for a array, and your pointer camImages are pointing for a new array, losing the reference for the old one you allocated previously.

So, whenever you take a new photo, a new memory position for the array will be allocated, with just the current image.

To resolve this problem, you should allocate this array only once, and use the same memory position for the array to add your images.

As Abdullah Shafique pointed, you can allocate this array once in the some previous method, like viewDidLoad, or just use lazy instantiation, with a if in your delegate method.

if(!camImages){
     camImages = [NSMutableArray new];
}