SwiftUI ScrollView 没有更新? [英] SwiftUI ScrollView not getting updated?

问题描述

目标

获取要显示在 scrollView

预期结果

实际结果

替代方案

使用List，但是不灵活(不能去掉分隔符，不能有多列)

use List, but it is not flexible (can't remove separators, can't have multiple columns)

代码

struct Object: Identifiable {
    var id: String
}

struct Test: View {
    @State var array = [Object]()

    var body: some View {
//        return VStack { // uncomment this to see that it works perfectly fine
        return ScrollView(.vertical) {
            ForEach(array) { o in
                Text(o.id)
            }
        }
        .onAppear(perform: {
            self.array = [Object(id: "1"),Object(id: "2"),Object(id: "3"),Object(id: "4"),Object(id: "5")]
        })
    }
}

推荐答案

解决这个问题的一个不太老套的方法是将 ScrollView 包含在检查数组是否为空的 IF 语句中

A not so hacky way to get around this problem is to enclose the ScrollView in an IF statement that checks if the array is empty

if !self.array.isEmpty{
     ScrollView(.vertical) {
          ForEach(array) { o in
               Text(o.id)
          }
     }
}

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