读取相册或者相机多张图片，同时按照一定的要求排列，并有删除添加功能

//
//  ViewController.m
//  text
//
//  Created by 123 on 16/4/29.
//  Copyright © 2016年 yipinbaike. All rights reserved.
//



#import "ViewController.h"

#define IMAGEVIEW_NUM_MAX 5

@interface ViewController ()<UIImagePickerControllerDelegate,UINavigationControllerDelegate,UIActionSheetDelegate>
{
    NSMutableArray * _imageViewArray;
    NSInteger _currentIndex;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    
    _imageViewArray = [[NSMutableArray alloc]init];
    UIImageView * imageView = [[UIImageView alloc]init];
    imageView.image = [UIImage imageNamed:@"请求失败"];
    [_imageViewArray addObject:imageView];
    [self.view addSubview:imageView];
    [self updateImageViewsFrame];
}

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{
    if (buttonIndex==2) {
        return;
    }
    UIImagePickerController * picker = [[UIImagePickerController alloc]init];
    picker.delegate = self;
    picker.allowsEditing = YES;
    if (buttonIndex==0&&[UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        picker.sourceType =UIImagePickerControllerSourceTypeCamera;
    }
    else if (buttonIndex==1&&[UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    }
    [self presentViewController:picker animated:YES completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
    UIImageView * currentImageView  =(UIImageView*)_imageViewArray[_currentIndex];
    currentImageView.image = info[UIImagePickerControllerEditedImage];
    [picker dismissViewControllerAnimated:YES completion:nil];
    UIButton * delBtn = [[UIButton alloc]initWithFrame:CGRectMake(currentImageView.frame.size.width-20, -10, 30,30)];
    [currentImageView addSubview:delBtn];
    [delBtn addTarget:self action:@selector(delBtnTouched:) forControlEvents:UIControlEventTouchUpInside];
    delBtn.backgroundColor = [UIColor blackColor];
    
    if (_imageViewArray.count<IMAGEVIEW_NUM_MAX&&_currentIndex==_imageViewArray.count-1) {
        UIImageView * imageView = [[UIImageView alloc]init];
        imageView.image = [UIImage imageNamed:@"请求失败"];
        [self.view addSubview:imageView];
        [_imageViewArray addObject:imageView];
        [self updateImageViewsFrame];
    }
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [picker dismissViewControllerAnimated:YES completion:nil];
}

- (void)updateImageViewsFrame{
    CGFloat imageWeight = 100;
    CGFloat imageHight = 100;
    CGFloat sepW = (self.view.frame.size.width - imageWeight*3-20*2)/2;
    CGFloat sepH = 20.0f;
    for (int i = 0; i<_imageViewArray.count; i++) {
        UIImageView * imageView= _imageViewArray[i];
        NSInteger row = i/3;//计算行数
        NSInteger que = i%3; //计算列数
        imageView.frame = CGRectMake(20+que*(imageWeight+sepW), 30+row*(imageHight+sepH), imageWeight, imageHight);
        imageView.tag = i;
        UITapGestureRecognizer * ges = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(imageViewTouched:)];
        [imageView addGestureRecognizer:ges];
        imageView.userInteractionEnabled = YES;
        for (UIView * view in imageView.subviews) {
            if ([view isKindOfClass:[UIButton class]]) {
                view.tag = i;
            }
        }
    }
}

- (void)imageViewTouched:(UIGestureRecognizer*)ges{
    UIActionSheet * actionSheet = [[UIActionSheet alloc]initWithTitle:nil delegate:self cancelButtonTitle:@"取消" destructiveButtonTitle:@"拍照" otherButtonTitles:@"相册", nil];
    [actionSheet showInView:self.view];
    actionSheet.cancelButtonIndex = 2;
    _currentIndex = ges.view.tag;
}
- (void)delBtnTouched:(UIButton*)btn{
    [((UIImageView*)_imageViewArray[btn.tag]) removeFromSuperview];
    [_imageViewArray removeObjectAtIndex:btn.tag];
    [self updateImageViewsFrame];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end