Set the initially visible item LazyGrid (swiftUI)

Question

I'm trying to set the initially visible item LazyGrid (swiftUI)

The idea is instead of the initial value be the default (0)

the initial value became the value I chose, for instance 4

with the possibility of move the grid to 0 and to 9.

I have simple grid

import SwiftUI

struct ContentView: View {
    var body: some View {

        ScrollView(.horizontal, showsIndicators: false) {
          
            LazyHGrid(rows: [GridItem(.flexible(minimum: 200, maximum: 200))]) {
                ForEach(0 ..< 10){ val in

                    ZStack{

                    Rectangle()
                        .foregroundColor(.gray)
                        .frame(width: 200, height: 200)
                        
                        
                        Text("\(val)")
                            .fontWeight(.bold)
                            .font(.title)
                            .foregroundColor(.white)
                    }
                }
            }
        }
    }
}

user_12299030 · Answer

SwfitUI 2.0

There is ScrollViewReader for this purpose. We give id for views and by scroll view proxy specify which view should be visible.

Here is a demo. Tested with Xcode 12 / iOS 14

struct DemoView: View {
    let initiail: Int = 4

    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            ScrollViewReader { sp in
                LazyHGrid(rows: [GridItem(.flexible(minimum: 200, maximum: 200))]) {
                    ForEach(0 ..< 10, id: \.self){ val in

                        ZStack{

                        Rectangle()
                            .foregroundColor(.gray)
                            .frame(width: 200, height: 200)


                            Text("\(val)")
                                .fontWeight(.bold)
                                .font(.title)
                                .foregroundColor(.white)
                        }.id(val)
                    }
                }.onAppear { sp.scrollTo(initiail) }
            }
        }
    }
}

Set the initially visible item LazyGrid (swiftUI)

1 Answers