当父视图具有日期选择器SwiftUI时,不会调用onPreferenceChange

时间:2020-09-30 20:28:00

标签: ios swift swiftui

我有一个父视图,其中有两个子视图。

当子视图更改首选项值时,父视图通过onPreferenceChange接收首选项更改 但是,当父母有日期选择器时,onPreferenceChange不会被调用并停止工作。 有人找到任何解决方法吗?

struct parentView: View {

@State private var date = Date()

var body: some View {
    
    VStack{
        
        ChildView1()
        
        Text("Child View 2")
    
       // DatePicker("", selection: self.$date, displayedComponents: .hourAndMinute)
       

    }
    .onPreferenceChange(testPreference.self, perform: { value in
        print("Printing preference value")
        print(value)
    })
 }
}


struct ChildView1: View {

@State private var tablets : Int = 0

var body: some View {
    Text("Child View 1")
        .onTapGesture {
            self.tablets = self.tablets + 1
        }
        .preference(key: testPreference.self, value: self.tablets)

  }
}


struct testPreference: PreferenceKey {

typealias Value = Int

static var defaultValue: Int = 0

static func reduce(value: inout Int, nextValue: () -> Int) {
    value = nextValue()
  }
}

0 个答案:

没有答案