Swift学习第一练——用Swift实现的FlappyBird小游戏

怼烎@ 2022-01-26 12:19 189阅读 0赞

## 用Swift实现的FlappyBird小游戏 ##

伴随着apple公司对swift的推广态度深入，swift火的很快，并且swift精简便捷的语法和强大的功能，对于使用Object—C开发iOS的开发者来说，也有必要了解学习一下swift。这篇博客跳过swift干涩的语法，直接从一个小游戏项目开始使用swift，将其中收获总结如下：

FlappyBird是前段时间很火的一款小游戏，通过手指点击屏幕平衡小鸟通过障碍。我是将以前OC版的项目拿来改成了swift，所以整体的思路还是OC的开发思路。

首先，我需要定义两个宏，一个用来模拟重力加速度G，一个用来便捷获取设备屏幕尺寸。因为这个游戏非常简单，开发起来也只需要几个小时，所以我们只需要在一个文件中写代码：viewController.swift。

swift中没有一般语言中的宏定义，但是可以通过定义常量的形式实现宏的效果：

[?][Link 1]

我们需要定义一些成员变量，如下：

[?][Link 1]

对于？和！号的理解，网上概念很多，简单理解声明变量时如果不初始化系统是不会给变量赋nil的，会报错，？的作用就是告诉系统这里如果没有初始化就是nil。同理，在用这类变量的时候，也需要加上？解包，如果加！就是强制解包，可以理解为让系统认为这个变量一定不是nil。

对于UI的创建等部分函数和OC一样，只是调用的方式略有不同，后面会附上源码。

在控制小鸟下落的部分代码如下，其中有一点需要注意，在swift中没有隐士转换这个概念，比如你要使用int a + float b 你必须手动将int转为float:(Float)(a)+b

[?][Link 1]

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     </div> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

游戏效果图如下：

[![165325\_TOIO\_2340880.png][165325_TOIO_2340880.png]][165325_TOIO_2340880.png]

[![165343\_JoFU\_2340880.png][165343_JoFU_2340880.png]][165343_JoFU_2340880.png]

我相信，实践是学习的必经途径，希望与志同道合的朋友，一起进步。

[Link 1]: http://my.oschina.net/u/2340880/blog/465668#
[165325_TOIO_2340880.png]: /images/20220126/c9c5b40351c54309a6f3e4850efb2c3f.png
[165343_JoFU_2340880.png]: /images/20220126/3bb06291304b49928f3d00c4ed5bba3b.png