尝试使用下面选项的.frame修饰符:

.frame(
      minWidth: 0,
      maxWidth: .infinity,
      minHeight: 0,
      maxHeight: .infinity,
      alignment: .topLeading
    )

struct ContentView: View {
  var body: some View {
    VStack(alignment: .leading) {
      Text("Hello World")
        .font(.title)
      Text("Another")
        .font(.body)
      Spacer()
    }
    .frame(
      minWidth: 0,
      maxWidth: .infinity,
      minHeight: 0,
      maxHeight: .infinity,
      alignment: .topLeading
    )
    .background(Color.red)
  }
}

这被描述为一个灵活的框架(请参阅文档)，它将拉伸以填充整个屏幕，当它有额外的空间时，它将在其中居中其内容。

我知道这并不适用于所有人，但我认为有趣的是，只需添加一个分隔器就可以解决这个问题。

struct DividerTest: View {
var body: some View {
    VStack(alignment: .leading) {
        Text("Foo")
        Text("Bar")
        Divider()
    }.background(Color.red)
  }
}

另一种选择是在HStack中放置一个子视图，并在它之后放置一个Spacer():

struct ContentView : View {
    var body: some View {
        VStack(alignment: .leading) {

            HStack {
                Text("Title")
                    .font(.title)
                    .background(Color.yellow)
                Spacer()
            }

            Text("Content")
                .lineLimit(nil)
                .font(.body)
                .background(Color.blue)

            Spacer()
            }

            .background(Color.red)
    }
}

导致:

使用SwiftUI设计登录页面

import SwiftUI

struct ContentView: View {

    @State var email: String = "william@gmail.com"
    @State var password: String = ""
    @State static var labelTitle: String = ""


    var body: some View {
        VStack(alignment: .center){
            //Label
            Text("Login").font(.largeTitle).foregroundColor(.yellow).bold()
            //TextField
            TextField("Email", text: $email)
                .textContentType(.emailAddress)
                .foregroundColor(.blue)
                .frame(minHeight: 40)
                .background(RoundedRectangle(cornerRadius: 10).foregroundColor(Color.green))

            TextField("Password", text: $password) //Placeholder
                .textContentType(.newPassword)
                .frame(minHeight: 40)
                .foregroundColor(.blue) // Text color
                .background(RoundedRectangle(cornerRadius: 10).foregroundColor(Color.green))

            //Button
            Button(action: {

            }) {
                HStack {
                    Image(uiImage: UIImage(named: "Login")!)
                        .renderingMode(.original)
                        .font(.title)
                        .foregroundColor(.blue)
                    Text("Login")
                        .font(.title)
                        .foregroundColor(.white)
                }


                .font(.headline)
                .frame(minWidth: 0, maxWidth: .infinity)
                .background(LinearGradient(gradient: Gradient(colors: [Color("DarkGreen"), Color("LightGreen")]), startPoint: .leading, endPoint: .trailing))
                .cornerRadius(40)
                .padding(.horizontal, 20)

                .frame(width: 200, height: 50, alignment: .center)
            }
            Spacer()

        }.padding(10)

            .frame(minWidth: 0, idealWidth: .infinity, maxWidth: .infinity, minHeight: 0, idealHeight: .infinity, maxHeight: .infinity, alignment: .top)
            .background(Color.gray)

    }

}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

尝试使用下面选项的.frame修饰符:

.frame(
      minWidth: 0,
      maxWidth: .infinity,
      minHeight: 0,
      maxHeight: .infinity,
      alignment: .topLeading
    )

struct ContentView: View {
  var body: some View {
    VStack(alignment: .leading) {
      Text("Hello World")
        .font(.title)
      Text("Another")
        .font(.body)
      Spacer()
    }
    .frame(
      minWidth: 0,
      maxWidth: .infinity,
      minHeight: 0,
      maxHeight: .infinity,
      alignment: .topLeading
    )
    .background(Color.red)
  }
}

这被描述为一个灵活的框架(请参阅文档)，它将拉伸以填充整个屏幕，当它有额外的空间时，它将在其中居中其内容。

编辑:答案更新为使用.frame的简单(更好)方法

只要使用帧修饰器!

struct Expand: View {
    var body: some View {
        VStack(alignment: .leading) {
            Text("Title")
                .font(.title)
            
            Text("Content")
                .lineLimit(nil)
                .font(.body)
        }
        .frame(maxWidth:.infinity,maxHeight:.infinity,alignment:.topLeading)
        .background(Color.red)
    }
}

注意-你甚至不需要VStack中的spacer !

注意2:如果你不想在顶部和底部使用白色，那么在背景中使用:

Color.red.edgesIgnoringSafeArea(.all)