Sbt在多项目中，将设置放置在文件或commonSettings中有什么区别

初学者的问题是，我有一个多项目的sbt文件，如果我把一般设置放在文件的开头会有区别吗？e、 g:

organization := "com.example"
  version := "0.0.1-SNAPSHOT"
  scalaVersion := "2.11.12"
resolvers ++= Seq(
    "Apache Development Snapshot Repository" at "https://repository.apache.org/content/repositories/snapshots/",
    "Typesafe repository" at "http://repo.typesafe.com/typesafe/releases/",

    Resolver.mavenLocal
  )
assemblyMergeStrategy in assembly := {
    case PathList("META-INF", xs @ _*) => MergeStrategy.discard
    case x => MergeStrategy.first
  }
lazy val commonSettings  = Seq(  libraryDependencies ++= commonDependencies ++ testingDependencies)
lazy val sharedProject = (project in file(...))
.settings(commonSettings: _*)
val projectA = .....dependsOn(sharedPorject)
val projectB = .....dependsOn(sharedPorject)

或者如果我把它放在公共设置中

lazy val commonSettings  = Seq(  
organization := "com.example",
  version := "0.0.1-SNAPSHOT",
  scalaVersion := "2.11.12",
resolvers ++= Seq(
    "Apache Development Snapshot Repository" at "https://repository.apache.org/content/repositories/snapshots/",
    "Typesafe repository" at "http://repo.typesafe.com/typesafe/releases/",
    Resolver.mavenLocal
  ),
assemblyMergeStrategy in assembly := {
    case PathList("META-INF", xs @ _*) => MergeStrategy.discard
    case x => MergeStrategy.first
  },
libraryDependencies ++= commonDependencies ++ testingDependencies)
lazy val sharedProject = (project in file(...))
.settings(commonSettings: _*)
val projectA = .....dependsOn(sharedPorject)
val projectB = .....dependsOn(sharedPorject)

---

区别是什么？

任何未将其附加到特定项目设置（即

.settings（）

）而定义的设置都附加到根项目

这样的代码

organization := "foo"

与

lazy val root = (project in file(".")).settings(organization := "foo")

现在，如果您定义了一个新的子项目，如

common

，并向其中添加

organization

lazy val common = (project in file("common")).settings(organization := "bar")

只有它的值

组织

设置为

条形

当根项目也定义了自己的

组织时，这将在示例中保持不变

lazy val root = (project in file(".")).settings(organization := "foo")

lazy val common = (project in file("common")).settings(organization := "bar")

这很容易用命令
sbt“show organization”
和
sbt“show common/organization”
进行测试。它将分别打印
foo
和
bar

最后，如果希望为所有子项目定义相同的值，请在根项目中为scope
ThisBuild
添加设置，如本例所示：

organization in ThisBuild := "foo"

lazy val common = (project in file("common")).settings(???)

或者将设置存储在
Seq
中，并将其应用于所有子项目和根项目。这将具有与scope
ThisBuild
中类似的效果，但更为明确：

val commonSettings = Seq(organization := "foo")

lazy val root = (project in file(".")).settings(commonSettings)
lazy val common = (project in file("common")).settings(commonSettings)