【发布时间】:2021-07-09 07:32:14
【问题描述】:
当我第一次启动我的应用程序时,工具栏图标会显示并且可以正常工作,但它们最初是灰色的,直到将鼠标悬停在按钮上。
应用的首次运行:
然后鼠标悬停:
代码如下:
import SwiftUI
struct ContentView: View
{
@State var mainList:[String] = ["Alpha", "Bravo", "Charlie", "Delta", "Echo", "Foxtrot", "Golf", "Hotel", "Indigo", "Juliet", "Kilo", "Lima", "Mike", "November", "Oscar", "Papa", "Quebec", "Romeo", "Sierra", "Tango", "Uniform", "Victor", "Whisky", "Xray", "Yankee", "Zulu"]
@State var selectedItem:String? = "Echo"
var body: some View
{
NavigationView
{
List()
{
ForEach(mainList, id: \.self)
{item in
NavigationLink(destination: DetailView(item: item), tag: item, selection: $selectedItem, label:
{
Text("\(item)")
})
}
}
}
.toolbar
{
Button(action: {addNewItem()})
{
Label("Select", systemImage: "square.and.pencil")
}
}
}
func addNewItem()
{
print ("Add item")
}
}
struct DetailView: View
{
@State var item: String
var body: some View
{
Text(item)
}
}
这是在 Xcode 12.5.1 和 Xcode 13.0 测试版中。
我原以为应该使用此代码在活动时启用工具栏。是错误还是我做错了什么?
【问题讨论】: