186使用系统内的相册

PS：对于 Camera 选项，会调用摄像头，需要真机才能测试。

效果如下：

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController <UIActionSheetDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate>
@property (strong, nonatomic) UIImageView *imgVCustom;

@end

ViewController.m

#import "ViewController.h"

@interface ViewController ()
- (void)layoutUI;
- (void)showActionSheet:(UIBarButtonItem *)sender;
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self layoutUI];
}

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

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self.navigationController setNavigationBarHidden:NO animated:animated];
    [self.navigationController setToolbarHidden:NO animated:animated];
}

- (void)layoutUI {
    self.navigationItem.title = @"使用系统内的相册";
    self.view.backgroundColor = [UIColor whiteColor];
    UIBarButtonItem *barBtnChooseImage = [[UIBarButtonItem alloc]
                                          initWithBarButtonSystemItem:UIBarButtonSystemItemCamera
                                          target:self
                                          action:@selector(showActionSheet:)];
    self.toolbarItems = @[barBtnChooseImage];
    
    _imgVCustom = [[UIImageView alloc] initWithFrame:self.view.bounds];
    _imgVCustom.contentMode = UIViewContentModeScaleAspectFit;
    _imgVCustom.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    _imgVCustom.image = [UIImage imageNamed:@"1"];
    [self.view addSubview:_imgVCustom];
}

- (void)showActionSheet:(UIBarButtonItem *)sender {
    UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:@"选择相册"
                                                             delegate:self
                                                    cancelButtonTitle:@"取消"
                                               destructiveButtonTitle:nil
                                                    otherButtonTitles:@"PhotoLibrary", @"Camera", @"SavedPhotosAlbum", nil];
    [actionSheet showFromToolbar:self.navigationController.toolbar];
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
    if (error) {
        NSLog(@"%@", [error localizedDescription]);
    }
}

#pragma mark - UIActionSheetDelegate
- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex {
    if (buttonIndex != actionSheet.cancelButtonIndex) {
        UIImagePickerControllerSourceType sourceType = buttonIndex;
        if ([UIImagePickerController isSourceTypeAvailable:sourceType]) {
            UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
            imagePickerController.delegate = self;
            imagePickerController.sourceType = sourceType;
            imagePickerController.allowsEditing = YES;
            [self presentViewController:imagePickerController
                               animated:YES
                             completion:nil];
        }
    }
}

#pragma mark - UIImagePickerControllerDelegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    UIImage *imgChoice = [info objectForKey:UIImagePickerControllerEditedImage];
    if (!imgChoice) {
        imgChoice = [info objectForKey:UIImagePickerControllerOriginalImage];
    }
    _imgVCustom.image = imgChoice;
    
    //把图片保存到相册
//    UIImageWriteToSavedPhotosAlbum(imgChoice,
//                                   self,
//                                   @selector(image:didFinishSavingWithError:contextInfo:),
//                                   NULL);
    
    [self imagePickerControllerDidCancel:picker];
}

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

@end

AppDelegate.h

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) UINavigationController *navigationController;

@end

AppDelegate.m

#import "AppDelegate.h"
#import "ViewController.h"

@interface AppDelegate ()
@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    _window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    ViewController *viewController = [[ViewController alloc] init];
    _navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
    _window.rootViewController = _navigationController;
    //[_window addSubview:_navigationController.view]; //当_window.rootViewController关联时，这一句可有可无
    [_window makeKeyAndVisible];
    return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application {
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
}

- (void)applicationWillEnterForeground:(UIApplication *)application {
}

- (void)applicationDidBecomeActive:(UIApplication *)application {
}

- (void)applicationWillTerminate:(UIApplication *)application {
}

@end