What is the difference between List and ForEach in SwiftUI?

问题

I know SwiftUI does not support currently regular for loops but instead provide something called ForEach but what is the difference between that and a List?

回答1:

• ForEach is a view that lets you pass a collection of data to its initializer and then creates multiple "subviews" from the closure you provide. It doesn't have any semantics on how the views will be arranged.

  Example:

  ForEach(1...5) { row in
      Text("Row \(row)")
  }
  

  will create the equivalent off

  Text("Row 1")
  Text("Row 2")
  Text("Row 3")
  Text("Row 4")
  Text("Row 5")
  

  wrapped in a single container view.

• List is a view that can compose multiple views together, but not necessarily views of the same type. You can simply add multiple views without any loop.

  Example 1:

  List {
      Image("avatar")
      Text("Title")
      Button(action: {
          print("Button tapped!")
      }) {
          Text("Energize!")
      }
  }
  

  As a convenience, the List initializer allows you to use it just like the ForEach view in case you want to have a list consisting of a single cell type only.
  

  Example 2:

  List(1...5) { row in
      Text("Row \(row)")
  }
  

  A list has a special appearance, depending on the platform. For example, on iOS a list will appear as a table view and insert separator lines between its vertically stacked views.

  You can use ForEach views inside List views to have both dynamic and static content – a very powerful feature of SwiftUI.
  
  

  Example 3:

  List {
      Text("Food")
      ForEach(meals) { meal in
          Text(meal.name)
      }
      Text("Drinks")
      ForEach(drinks) { drink in
          Text(drink.name)
      }
  }
  

回答2:

List:

• mixed content(also allows to work with collection)
• scrollable
• uses reusing cell pattern (efficient)

ForEach:

• works only with a collection

List + ForEach = super feature. In this case, for example, List uses reusing cell pattern for every view from ForEach. Also you are able to use onMove, onDelete...

来源：https://stackoverflow.com/questions/56535326/what-is-the-difference-between-list-and-foreach-in-swiftui