下面的Test5是调用：
public static void Test5()
{
string englishName = "apple";
string chineseName = englishName.Switch(
new string[] { "apple", "orange", "banana", "pear" },
new string[] { "苹果", "桔子", "香蕉", "梨" },
"未知"
);
Console.WriteLine(chineseName);
}
{
string englishName = "apple";
string chineseName = englishName.Switch(
new string[] { "apple", "orange", "banana", "pear" },
new string[] { "苹果", "桔子", "香蕉", "梨" },
"未知"
);
Console.WriteLine(chineseName);
}
简单清晰!
最后是一个对while的扩展封装：
public static void While<T>(this T t, Predicate<T> predicate, Action<T> action) where T: class
{
while (predicate(t)) action(t);
}
{
while (predicate(t)) action(t);
}
调用代码：
public static void Test6()
{
People people = new People { Name = "Wretch" };
people.While(
p => p.WorkCount < 7,
p => p.Work()
);
people.Rest();
}
{
People people = new People { Name = "Wretch" };
people.While(
p => p.WorkCount < 7,
p => p.Work()
);
people.Rest();
}
这while扩展中只能执行一个Action，不太好，我们用params改进一下：
public static void While<T>(this T t, Predicate<T> predicate, params Action<T>[] actions) where T : class
{
while (predicate(t))
{
foreach (var action in actions)
action(t);
}
}
{
while (predicate(t))
{
foreach (var action in actions)
action(t);
}
}
再来调用，可以在循环中执行多个操作了。
public static void Test7()
{
People people = new People { Name = "Wretch" };
people.While(
p => p.WorkCount < 7,
p => p.Work(),
p => p.Eat(),
p => p.Drink(),
p => p.Rest()
);
people.Rest();
}
{
People people = new People { Name = "Wretch" };
people.While(
p => p.WorkCount < 7,
p => p.Work(),
p => p.Eat(),
p => p.Drink(),
p => p.Rest()
);
people.Rest();
}
当然前面的If也可以这样的，这里只写出一个：
public static T If<T>(this T t, Predicate<T> predicate, params Action<T>[] actions) where T : class
{
if (t == null) throw new ArgumentNullException();
if (predicate(t))
{
foreach (var action in actions)
action(t);
}
return t;
}
{
if (t == null) throw new ArgumentNullException();
if (predicate(t))
{
foreach (var action in actions)
action(t);
}
return t;
}
不使用 params，你就要显示声明一个Action的集合了!关于params， 在我的随笔《改进 Scottgu 的 "In" 扩展 》有说明。
