I tried searching using Google Search and Stack Overflow, but it didn't show up any results. I have seen this in opensource library code:
Notification notification = new Notification(icon, tickerText, when);
notification.defaults |= Notification.DEFAULT_SOUND;
notification.defaults |= Notification.DEFAULT_VIBRATE;
"|="(pipe equal operator)是什么意思？
|=的读数与+=的读数相同.
notification.defaults |= Notification.DEFAULT_SOUND;
和
notification.defaults = notification.defaults | Notification.DEFAULT_SOUND;
其中|是逐位OR运算符.
所有操作员的标号均为here.
使用按位运算符是因为，正如经常发生的那样，这些常量使int能够携带标志.
如果你计算这些常数，你会发现它们是二的幂:
public static final int DEFAULT_SOUND = 1;
public static final int DEFAULT_VIBRATE = 2; // is the same than 1<<1 or 10 in binary
public static final int DEFAULT_LIGHTS = 4; // is the same than 1<<2 or 100 in binary
因此，您可以使用按位OR添加标志
int myFlags = DEFAULT_SOUND | DEFAULT_VIBRATE; // same as 001 | 010, producing 011
所以
myFlags |= DEFAULT_LIGHTS;
简单地说就是我们加了一面旗帜.
对称地，我们用&测试一个标志:
boolean hasVibrate = (DEFAULT_VIBRATE & myFlags) != 0;