1     //初始化提示框；2     UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"提示" message:@"按钮被点击了" preferredStyle: UIAlertControllerStyleAlert];3     4     [alert addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {5         //点击按钮的响应事件；6     }]];7     8     //弹出提示框；9     [self presentViewController:alert animated:true completion:nil];