不多说,直接上代码

import "ViewController.h"

@interface ViewController ()<UIImagePickerControllerDelegate,UIActionSheetDelegate>

@property(nonatomic,strong)UIButton *btn;
@property(nonatomic,strong)UIActionSheet *actionSheet;

@end

@implementation ViewController

• (void)viewDidLoad {
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
  _btn = [UIButton buttonWithType:UIButtonTypeSystem];
  _btn.frame = CGRectMake(80, 200, 200, 200);
  _btn.backgroundColor = [UIColor yellowColor];
  [_btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
  [_btn setTitle:@"点我" forState:UIControlStateNormal];
  [self.view addSubview:_btn];
  }

• (void)btnClick:(UIButton *)sender
  {
  [self openActionSheetFunc];
  }

//调用ActionSheet

• (void)openActionSheetFunc
  {
  //判断设备是否有具有摄像头(相机)功能
  if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
  {
  _actionSheet = [[UIActionSheet alloc]initWithTitle:@"选择图像" delegate:self cancelButtonTitle:@"取消" destructiveButtonTitle:nil otherButtonTitles:@"拍照",@"从相册选择", nil];
  }
  else
  {
  _actionSheet = [[UIActionSheet alloc]initWithTitle:@"选择图像" delegate:self cancelButtonTitle:@"取消" destructiveButtonTitle:nil otherButtonTitles:@"从相册选择", nil];
  }
  _actionSheet.tag = 100;
  //显示提示栏
  [_actionSheet showInView:self.view];
  }

• (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
  {
  if (actionSheet.tag == 100)
  {
  NSUInteger sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
  if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
  {
  switch (buttonIndex)
  {
  case 0:
  //来源:相机
  sourceType = UIImagePickerControllerSourceTypeCamera;
  break;
  case 1:
  //来源:相册
  sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
  break;
  case 2:
  return;
  }
  }
  else
  {
  if (buttonIndex == 2)
  {
  return;
  }
  else
  {
  sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
  }
  }
  //跳转到相机或者相册页面
  UIImagePickerController *imagePickerController = [[UIImagePickerController alloc]init];
  imagePickerController.allowsEditing = YES;
  imagePickerController.sourceType = sourceType;
  imagePickerController.delegate = self;
  [self presentViewController:imagePickerController animated:YES completion:nil];
  }
  }

//pickerController的代理

• (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
  {
  [picker dismissViewControllerAnimated:YES completion:nil];
  UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
  [_btn setBackgroundImage:image forState:UIControlStateNormal];
  }

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

@end