代码：

UIAlertController *alertViewController = [UIAlertController alertControllerWithTitle:@"请选择方式" message:nil preferredStyle:UIAlertControllerStyleActionSheet];// style 为 sheet
UIAlertAction *cancle = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];
UIAlertAction *picture = [UIAlertAction actionWithTitle:@"相册" style:UIAlertActionStyleDefault handler:nil];//handler里可以写需要的函数
UIAlertAction *photo = [UIAlertAction actionWithTitle:@"相机" style:UIAlertActionStyleDefault handler:nil];//同理
[alertViewController addAction:cancle];
[alertViewController addAction:photo];
[alertViewController addAction:picture];
[self presentViewController:alertViewController animated:YES completion:nil];

handle处理格式如下：

UIAlertAction *picture = [UIAlertAction actionWithTitle:@"相册" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
    <#code#>
}];//handler里可以写需要的函数

效果图如下：