UIImagePickerController 用法

//首选需要遵循协议 
<UIImagePickerControllerDelegate,UINavigationControllerDelegate>


//如果是imageView的话， interactionEnabled必须设置为YES
    self.headImageView.userInteractionEnabled = YES;
    UITapGestureRecognizer * tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(respondToTapGesture:)];
    [self.headImageView addGestureRecognizer:tapGesture];

//手势方法
-(void)respondToTapGesture:(UITapGestureRecognizer *)gestrue{

        UIImagePickerController * imageController = [[UIImagePickerController alloc]init];
        imageController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

//数据源类型有三种
 ![UIImagePickerControllerSourceTypePhotoLibrary](http://img.blog.youkuaiyun.com/20160502162802766)

UIImagePickerControllerSourceTypeCamera
这种方式直接打开设备相机取图

![UIImagePickerControllerSourceTypeSavedPhotosAlbum
](http://img.blog.youkuaiyun.com/20160502163631270)

        imageController.allowsEditing = YES; //设置可以编辑
        imageController.delegate = self;//设定委托
        [self presentViewController:imageController animated:YES completion:nil];
}


//UIImagePickerControllerDelegate 协议方法

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
    UIImage *image = info[@"UIImagePickerControllerEditedImage"];
    self.headImageView.image = image;
    [self dismissViewControllerAnimated:YES completion:nil];
}