SwiftUI使用

Posted on 2021-12-06 Edited on 2025-02-18 Views:

查询超过两次的必须记录😂

方法

常规

预览显示暗黑模式 .environment(\.colorScheme, .dark)

/// push 跳转
@State var selection: Int? = nil
NavigationLink(destination: TOMainView(), tag: 1, selection: $selection) {

    Button(action: {
        self.selection = 1
    }) {
        Text("Get Started")
            .frame(minWidth: 220)
            .font(.system(size: 24, weight: .semibold))
            .padding()
            .foregroundColor(Color(uiColor: UIColor(rgb: 0x6644ab)))
            .overlay(
                RoundedRectangle(cornerRadius: 25)
                    .stroke(Color.white, lineWidth: 0)
        )
    }
    .background(Color.white.opacity(0.85)) // If you have this
.cornerRadius(25)
}
/// 直接更换vc
if let window = UIApplication.shared.windows.first {
        window.rootViewController = UIHostingController(rootView: HomeScreen())
        window.makeKeyAndVisible()
    }

ObservedObject,StateObject,EnvironmentObject

@state，wrapped reference，系统自动update ui
@binding，binding type 链接 state object
Struct作为数据源，某一个property更改，会mutate整个struct，因为它是valuetype
ObservableObject不存储数据，class可以继承为此类型，然后定义@published属性，@ObservedObject就让@published产生一个类似@state的属性
StateObject存储数据
EnvironmentObject