如何在iOS中选择多个图像

Question

I am making an app for iPhone and want to give users the ability to multiselect images from their photo-library. I already have a working code for user to select four images at a time. But I can't select 2 or 3 images at a time. I want to select the 2 or 3 images at a time.

If I select 2 images I got exception like this: Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 3 beyond bounds [0 .. 2]

If I select 3 images I get exception like this: Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 2 beyond bounds [0 .. 1]'

If I click one image I get this exception like this: Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]' . I can't find a solution to this problem. How should I fix my code to make this work as expected?

Here's my code so far:

- (void)elcImagePickerController:(ELCImagePickerController *)picker didFinishPickingMediaWithInfo:(NSArray *)info

{

[self dismissViewControllerAnimated:YES completion:nil];

for (UIView *v in [_scrollView subviews]) 

{

[v removeFromSuperview];

 }

CGRect workingFrame = _scrollView.frame;

workingFrame.origin.x = 0;

NSMutableArray *images = [NSMutableArray arrayWithCapacity:[info count]];

for (NSDictionary *dict in info) 

{

UIImage *image = [dict objectForKey:UIImagePickerControllerOriginalImage];

[images addObject:image];

UIImageView *imageview = [[UIImageView alloc] initWithImage:image];

[imageview setContentMode:UIViewContentModeScaleAspectFit];

imageview.frame = workingFrame;

workingFrame.origin.x = workingFrame.origin.x + workingFrame.size.width;

self.chosenImages = images;

}

UIImageView *image1=[[UIImageView alloc]initWithFrame:CGRectMake(10, 240, 40, 40)];

image1.image=[images objectAtIndex:0];

[self.view addSubview:image1];

UIImageView *image2=[[UIImageView alloc]initWithFrame:CGRectMake(60, 240, 40, 40)];

image2.image=[images objectAtIndex:1];

[self.view addSubview:image2];

//self.chosenImages = images;

UIImageView *image3=[[UIImageView alloc]initWithFrame:CGRectMake(120, 240, 40, 40)];

image3.image=[images objectAtIndex:2];

[self.view addSubview:image3];

UIImageView *image4=[[UIImageView alloc]initWithFrame:CGRectMake(180, 240, 40, 40)];

image4.image=[images objectAtIndex:3];

[self.view addSubview:image4];

[_scrollView setPagingEnabled:YES];

[_scrollView setContentSize:CGSizeMake(workingFrame.origin.x, workingFrame.size.height)];

}

Answer 1

This error is telling you the image index which you are selecting is beyond of array.

for eg

your array having item at index [0,1,2,3] and you are selecting item from index like 4 and 5

Answer 2

Your code tells about your crash.

UIImageView *image1=[[UIImageView alloc]initWithFrame:CGRectMake(10, 240, 40, 40)];

image1.image=[images objectAtIndex:0];

[self.view addSubview:image1];

UIImageView *image2=[[UIImageView alloc]initWithFrame:CGRectMake(60, 240, 40, 40)];

image2.image=[images objectAtIndex:1];

[self.view addSubview:image2];

//self.chosenImages = images;

UIImageView *image3=[[UIImageView alloc]initWithFrame:CGRectMake(120, 240, 40, 40)];

image3.image=[images objectAtIndex:2];

[self.view addSubview:image3];

UIImageView *image4=[[UIImageView alloc]initWithFrame:CGRectMake(180, 240, 40, 40)];

image4.image=[images objectAtIndex:3];

[self.view addSubview:image4];

If I select 2 images I got exception like this: Terminating app due to uncaught exception 'NSRangeException', reason: ' * -[__NSArrayM objectAtIndex:]: index 3 beyond bounds [0 .. 2]

In this case you cant do [images objectAtIndex:3] . Because the array contains only 2 images. Likewise the other cases also.

UPDATE based on comment:

Just try adding [self.view addSubview:imageview ]; in your for loop like given below

for (NSDictionary *dict in info) 

{

    UIImage *image = [dict objectForKey:UIImagePickerControllerOriginalImage];

    [images addObject:image];

    UIImageView *imageview = [[UIImageView alloc] initWithImage:image];

    [imageview setContentMode:UIViewContentModeScaleAspectFit];

    imageview.frame = workingFrame;

    [self.view addSubview:imageview ];

    workingFrame.origin.x = workingFrame.origin.x + workingFrame.size.width;

    self.chosenImages = images;

}