Question

我尝试使用以下代码将新的.cpp文件添加到Visual Studio中的C项目中：

select
  t1.id,
  t1.strength,
  t1.agility,
  group_concat(t2.skill,',') bonuses
from table1 t1
left outer join
table2 t2
on t1.id = t2.id
where t1.id = 8
group by
  t1.id,
  t1.strength,
  t1.agility;

然而，import UIKit class ViewController: UIViewController,UIScrollViewDelegate { let scrollView = UIScrollView(frame: CGRectMake(0, 0, 320, 300)) var colors:[UIColor] = [UIColor.redColor(), UIColor.blueColor(), UIColor.greenColor(), UIColor.yellowColor()] var frame: CGRect = CGRectMake(0, 0, 0, 0) var pageControl : UIPageControl = UIPageControl(frame: CGRectMake(50, 300, 200, 50)) override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. configurePageControl() scrollView.delegate = self self.view.addSubview(scrollView) for index in 0..<4 { frame.origin.x = self.scrollView.frame.size.width * CGFloat(index) frame.size = self.scrollView.frame.size self.scrollView.pagingEnabled = true var subView = UIView(frame: frame) subView.backgroundColor = colors[index] self.scrollView .addSubview(subView) } self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * 4, self.scrollView.frame.size.height) pageControl.addTarget(self, action: Selector("changePage:"), forControlEvents: UIControlEvents.ValueChanged) } func configurePageControl() { // The total number of pages that are available is based on how many available colors we have. self.pageControl.numberOfPages = colors.count self.pageControl.currentPage = 0 self.pageControl.tintColor = UIColor.redColor() self.pageControl.pageIndicatorTintColor = UIColor.blackColor() self.pageControl.currentPageIndicatorTintColor = UIColor.greenColor() self.view.addSubview(pageControl) } // MARK : TO CHANGE WHILE CLICKING ON PAGE CONTROL func changePage(sender: AnyObject) -> () { let x = CGFloat(pageControl.currentPage) * scrollView.frame.size.width scrollView.setContentOffset(CGPointMake(x, 0), animated: true) } func scrollViewDidEndDecelerating(scrollView: UIScrollView) { let pageNumber = round(scrollView.contentOffset.x / scrollView.frame.size.width) pageControl.currentPage = Int(pageNumber) } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } }单独产生了100多个错误，因此我不得不对此进行评论以确定是否存在问题。执行此操作后，会弹出此新错误：#include <iostream> using namespace std; int main(int argc, char **argv) { cout << "Hello World!" << endl; return 0; }。我猜这是因为项目是以某种方式为C配置的，或者是因为预处理器有一些我不知道的事情。我怎么解决这个问题？

Answer 1

我尝试将新的.cpp文件添加到Visual Studio
中的C项目中

所以你知道它是C项目中的C ++代码。你知道C和C ++之间的区别是什么吗？如果是这样，您应该知道C没有using namespace或<iostream>，或<<运算符或cout。

如果您希望C ++文件在C项目中工作，您可以将项目配置为编译为C ++，将C ++文件转换为C代码，或者只是确保所有C ++文件都具有{{1} } extension（仅在C项目处于默认设置时才有效）。

标识符“using”未定义

1 个答案: