好久没有写技术文章了,今天就写一点点关于C#的使用心得吧。
1、代码问题:
以前我总是这样写代码:
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
后来这样写:
![](/Images/OutliningIndicators/None.gif)
再后来这样写:
![](/Images/OutliningIndicators/None.gif)
类似的有:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
后来就写成:
![](/Images/OutliningIndicators/None.gif)
有什么区别吗?没有,只能说我是越来越懒了。
字符串问题:
以前总是这样写:
![](/Images/OutliningIndicators/None.gif)
后来会这样写:
![](/Images/OutliningIndicators/None.gif)
再后来这样写:
![](/Images/OutliningIndicators/None.gif)
虽然有点麻烦,但比起因为路径出错而造成的麻烦,这算不了什么。
还有就是,以前这样写:
![](/Images/OutliningIndicators/None.gif)
后来这样写:
![](/Images/OutliningIndicators/None.gif)
理由就不用说了,安全第一。
还有一个就是:
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/None.gif)
后来总要这样:
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](/Images/OutliningIndicators/None.gif)
再后来:
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](/Images/OutliningIndicators/None.gif)
代码虽然越来越多,但安全性却是越来越高。总之,代码能省的地方就该省,不能省的,一个也不能少。
还有这样的问题:
以前这样写函数:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
后来一般情况我都会先选择这样的代码:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](/Images/OutliningIndicators/None.gif)
还有一个小问题,就是我喜欢在所有的成员使用上加上this,因为这样可以直接知道它是成员还是函数内的局部变量。
2、再讨论一个try-catch结结构:
以前这样写:
模块A中的某函数:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/None.gif)
后来遇到问题,在调用时不得不这样:
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
然而,这样问题就来了,当调用SomeFunction出现异常后,SomeFunction中的m_tempObject对象根本没有机会调用Dispose来释放资源。
于是修改代码为:
模块A中的函数:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
模块B中的调用:
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
然而这样还是有问题,就是你不知道调用模块A中的函数时,当返回null后,A中到底出现了什么问题。
也就是说,这里我想让B模块来Catch异常,而不想让A模块来处理。
简单的办法是在A模块的函数中catch到异常后,重新再抛出一个新异常:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
这样B模块中可以知道A中发生了什么事情,从而进一步处理。然而这样的问题是:
系统性能下降和异常类的改变。当然,如果直接抛出原来的异常也行,但那样没有必要,后来这样改代码:
模块A的函数:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/None.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
虽然B中还是用到了try-catch结构,但意义是不一样的。如果A是不可知模块,例如你是A模块提供方,那么这样的方法给你的用户提供了很好的灵活性。
如果你是A模块的使用方,那么你完全可以自己控制try-catch结构。
好了,先就这一点点心得。有时间再写一些。