unity升级对ab变更的影响

先上结论：.强烈不推荐拿打好的ab文件进行计算文件的二进制的MD5的方式，进行热更依据，应该优先使用unity自带的manifest文件进行比对文件是否变更：

Hashes:

AssetFileHash:

serializedVersion: 2

Hash: 3c741dda97883398c9222862d80a8f3b

TypeTreeHash:

serializedVersion: 2

Hash: 2612ac43db082a73502ee80f2eceb73f

IncrementalBuildHash:

serializedVersion: 2

Hash: 3c741dda97883398c9222862d80a8f3b

测试流程：把同一个svn的项目，拉倒同一台电脑上，三份，分别使用2022.3.55，2022.3.56，2022.3.62三个版本的unity打开，然后出ab包，比对hash值：

55

Hashes:

AssetFileHash:

serializedVersion: 2

Hash: bb747d5c74bf0a51dde018548c5e597a

TypeTreeHash:

serializedVersion: 2

Hash: 451bd7e8e27e78e817a64fc19e45eb64

IncrementalBuildHash:

serializedVersion: 2

Hash: bb747d5c74bf0a51dde018548c5e597a

56

Hashes:

AssetFileHash:

serializedVersion: 2

Hash: 6d6f2976af39aac1b429148ba4966ebe

TypeTreeHash:

serializedVersion: 2

Hash: 451bd7e8e27e78e817a64fc19e45eb64

IncrementalBuildHash:

serializedVersion: 2

Hash: 6d6f2976af39aac1b429148ba4966ebe

62

Hashes:

AssetFileHash:

serializedVersion: 2

Hash: 6d6f2976af39aac1b429148ba4966ebe

TypeTreeHash:

serializedVersion: 2

Hash: 451bd7e8e27e78e817a64fc19e45eb64

IncrementalBuildHash:

serializedVersion: 2

Hash: 6d6f2976af39aac1b429148ba4966ebe

如果我们现在改了一个预设上的代码的字段值，比如一个int值

55-2

Hashes:

AssetFileHash:

serializedVersion: 2

Hash: 19d416d8fc773f4e71f47475e15bec67

TypeTreeHash:

serializedVersion: 2

Hash: 451bd7e8e27e78e817a64fc19e45eb64

IncrementalBuildHash:

serializedVersion: 2

Hash: 19d416d8fc773f4e71f47475e15bec67

HashAppended: 0

如果我们又加了一个代码里的字段，比如加了一个int testID = 0;

55-2-3

Hashes:

AssetFileHash:

serializedVersion: 2

Hash: cac33e6d2da6a0cd7bff95feab86ad28

TypeTreeHash:

serializedVersion: 2

Hash: dc65370d4270a797d2eee811c5411216

IncrementalBuildHash:

serializedVersion: 2

Hash: cac33e6d2da6a0cd7bff95feab86ad28