1、// 1.判断数据源是否可用
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
// 2.打开相册
UIImagePickerController *ivPic = [[UIImagePickerController alloc] init];
ivPic.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
// 3.设置代理
ivPic.delegate = self;
// 4.显示图片选择器
[self presentViewController:ivPic animated:YES completion:nil];
}
2、实现下面的代理方法
（默认实现了下面的方法后，就需要手机释放图片选择器了）
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
// 1.取出选中的图片
UIImage *image = info[UIImagePickerControllerOriginalImage];
// 2.设置图片到imageview上
self.iconView.image = image;
// 3.关闭图片选择器
[picker dismissViewControllerAnimated:YES completion:nil];
}