flutter - Dart throw 和重新 throw 有什么区别？

Question

可能很明显，但是我仍然无法理解throw和rethrow之间的区别，什么时候应该使用它们中的任何一个？

Answer 1

根据Effective Dart:

If you decide to rethrow an exception, prefer using the rethrow statement instead of throwing the same exception object using throw. rethrow preserves the original stack trace of the exception. throw on the other hand resets the stack trace to the last thrown position.

最大的不同是保留了原始堆栈跟踪。

他们提供了两个示例以显示预期的用法:
坏:

try {
  somethingRisky();
} catch (e) {
  if (!canHandle(e)) throw e;
  handle(e);
}

好:

try {
  somethingRisky();
} catch (e) {
  if (!canHandle(e)) rethrow;
  handle(e);
}