SwiftUI Remove List padding fand Row spacing?

So this is what I have

The method you tried will work, but not on Lists, nest a ForEach inside of your list and then attach that modifier and you should be good. Also of course just tweak your modifiers to your liking of course.

Also, the way to get the spacing from between the list rows is setting a height limit on them. I just set 50 but again, modify as you see fit.

    struct Item {
    let uuid = UUID()
    let value: String
}

struct w_tasks: View {
    
    @State private var items = [Item]()
      
   
      var body: some View {
          ZStack(alignment: .leading){
           // List(self.items, id: \.uuid)
                    List {
                        ForEach(self.items, id: \.uuid) { item in
                            cl_task().listRowInsets(EdgeInsets(.init(top: 20, leading: -20, bottom: 20, trailing: -20)))
                            
                            .frame(height: 50)
                        }
                            
                    }
                    .listStyle(InsetListStyle())
                    
                    
                    .frame(width: UIScreen.main.bounds.width )
                    .onAppear {
                      
                        DispatchQueue.main.async {
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                            self.items.append(Item(value: "Item"))
                        }
               
                    }
              VStack {
                  Spacer()

                  HStack {
                      Spacer()

                      Button(action: {
                          self.items.append(Item(value: "Item"))
                      }, label: {
                          Text("+")
                          .font(.system(size: 30))
                          .frame(width: 50, height: 50)
                          .foregroundColor(Color.white)
                          .padding(.bottom, 5)
                      })
                      .background(Color("#216D94"))
                      .frame(width: 50, height: 50)
                      .cornerRadius(25)
                      .padding()
                      .shadow(color: Color.black.opacity(0.3),
                              radius: 3,
                              x: 3,
                              y: 3)
                  }
              }
          }.background(Color.black)
      }
}

struct w_tasks_Previews: PreviewProvider {

    static var previews: some View {
        w_tasks()
    }
}



struct cl_task: View {
    @State private var offset: CGSize = .zero
  
    var body: some View {
        //Swipe to custom options ,by "Jack" this option not yet available in SwiftUI
        let drag = DragGesture(minimumDistance: 25, coordinateSpace: .local)
       
                   .onChanged {
                    
                    if (self.offset.width > 0 ){  return }
                    self.offset.width = $0.translation.width
                
                   }.onEnded {
                   if $0.translation.width < -100 {
                       self.offset = .init(width: -100, height: 0)
                   } else {
                      self.offset = .zero
                   }
               }
        ZStack{
            Rectangle().foregroundColor(.blue).offset(x: offset.width, y: offset.height)
                .gesture(drag)
                .animation(.easeIn, value: offset)
            Text("test").foregroundColor(.white)
        }.frame(minWidth: 0,
                maxWidth: .infinity,
                minHeight: 120,
                maxHeight: .infinity,
                alignment: .topLeading
        )
    }
}

struct cl_task_Previews: PreviewProvider {
    static var previews: some View {
        cl_task().previewLayout(.sizeThatFits)
    }
}

For testing and showing that there is no problem with massive data, I pre loaded 10_000 row. is that enough?

your issues:

1.you should make your Item type Identifiable, then you can put out uuid from your list or ForEach.

2.you should not gave frame size to your row, they can take max space automatically.

3.you can put your button over your View, and save some more coding, like I did.

4.you should not use CGSize for offset, because you are just working on one dimension, and CGFloat is enough.

5.you should and must use LazyVStack if your data is massive as you said 400 is to many, then use LazyVStack for sure.

struct Item: Identifiable {

  let id: UUID = UUID()
  let value: String

}

struct ContentView: View {
    
    @State private var items: [Item] = [Item]()
    
    var body: some View {
        
        ZStack {
            
            Color.black.ignoresSafeArea()
            
            ScrollView {
                LazyVStack(spacing: 0) {
                    
                    ForEach(items) {item in
                        
                        RowView(stringOfText: item.value)
                            .frame(height: 120)
                    }
                    
                }
                
            }
            .background(Color.black)
            .onAppear() { for _ in 0...10_000 { addNewData() } }
            
            
            
        }
        .overlay(addButton, alignment: .bottomTrailing)
        .animation(.easeInOut)
        
    }
    
    var addButton: some View {
        
        Button(action: { addNewData() }, label: {
            Image(systemName: "plus.circle").foregroundColor(Color.white).font(Font.largeTitle.weight(Font.Weight.bold)).padding()
        })
        
        
    }
    
    func addNewData() { items.append(Item(value: "item " + items.count.description)) }
}

struct RowView: View {
    
    let stringOfText: String
    
    @State private var offset: CGFloat = CGFloat()
    
    var body: some View {
        
        ZStack {
            
            Color.blue
            
            Text(stringOfText)
                .foregroundColor(Color.white)
                .padding()
        }
        .offset(x: offset)
        .gesture(dragGesture)
        
    }
    
    var dragGesture: some Gesture {
        
        DragGesture(minimumDistance: 25, coordinateSpace: .local)
            
            .onChanged {
                if (offset > 0 ){  return }
                offset = $0.translation.width
                
            }.onEnded {
                if $0.translation.width < -100 {
                    offset = -100
                } else {
                    offset = 0
                }
            }
        
    }
  
}