更新时间:2023-02-05 19:26:56
选择类型必须是可选的.查找下面的固定代码.
Selection type must be optional. Find below fixed code.
struct TestListSelectionOnAction: View {
@State private var selection: Int? = 2 // optional !!
var body: some View {
VStack {
List(selection: $selection) {
Text("Line 0").tag(0)
Text("Line 1").tag(1)
Text("Line 2").tag(2)
Text("Line 3").tag(3)
Text("Line 4").tag(4)
Text("Line 5").tag(5)
}
.listStyle(SidebarListStyle())
Text("Selected Item :\(self.selection ?? -1)")
HStack {
Button(action: {
if (self.selection! < 5 ) { self.selection! += 1 }} ) {Text("⬇︎")}
Button(action: {
if (self.selection! > 0 ) { self.selection! -= 1 }} ) {Text("⬆︎")}
}
}
.frame(maxWidth: .infinity, maxHeight: .infinity)
}
}