编程技巧：Mixin（行为继承）

C#

interface SampleMixin {}
static class SampleExtension {
static void SampleMethod(this SampleMixin m) {
Console.WriteLine("default implementation");
}
static void SampleMethod2(this SampleClass c) {
Console.WriteLine("default implementation2");
}
}
class SampleClass : SampleMixin {}
new SampleClass().SampleMethod(); // default implementation
new SampleClass().SampleMethod2(); // default implementation2

Java

interface SampleMixin {
default void sampleMethod() {
System.out.println("default implementation");
}
}
class SampleClass implements SampleMixin {}
new SampleClass().sampleMethod(); // default implementation

Swift

protocol SampleMixin {
func sampleMethod()
}
extension SampleMixin {
func sampleMethod() {
print("default implementation")
}
}
class SampleClass : SampleMixin {}
SampleClass().sampleMethod() // default implementation