如何在ios中选择多个图像

Question

我正在为 iPhone 制作一个应用程序，并希望让用户能够从他们的照片库中多选图像。我已经有一个工作代码供用户一次选择四个图像。但我不能一次选择 2 或 3 张图像。我想一次选择 2 或 3 张图像。

如果我选择 2 张图片，我会收到如下异常：Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 3 beyond bounds [0 .. 2]

如果我选择 3 张图片，我会得到如下异常：Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 2 beyond bounds [0 .. 1]'

如果我单击一张图片，我会收到如下异常：Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]'。我找不到这个问题的解决方案。我应该如何修复我的代码以使其按预期工作？

到目前为止，这是我的代码：

- (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

这个错误告诉你你选择的图像索引超出了数组。

例如

您的数组在索引 [0,1,2,3] 处具有项目，并且您正在从索引中选择项目，例如 4 和 5

Answer 2

您的代码说明了您的崩溃。

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];

如果我选择 2 张图片，我会收到如下异常：Terminating app due to 未捕获的异常 'NSRangeException'，原因：'* -[__NSArrayM objectAtIndex:]: index 3 越界[0 .. 2]

在这种情况下你不能做[images objectAtIndex:3]。因为该数组仅包含 2 张图像。其他情况也一样。

根据评论更新：

只需尝试在您的 for 循环中添加 [self.view addSubview:imageview ];，如下所示

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;

}