在SwiftUI中,我们可以使用@EnvironmentObject
属性包装器来共享数据模型。当我们在视图层次结构中更新EnvironmentObject
变量时,我们可以通过协调器类来实现。
要从协调器类更新EnvironmentObject
变量,我们可以按照以下步骤进行操作:
ObservableObject
协议的数据模型类,该类将作为EnvironmentObject
共享给其他视图。class MyDataModel: ObservableObject {
@Published var myVariable: String = ""
}
SceneDelegate
中创建一个实例并将其设置为EnvironmentObject
。func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
let myDataModel = MyDataModel()
// 设置为EnvironmentObject
let contentView = ContentView().environmentObject(myDataModel)
// ...
}
@EnvironmentObject
属性包装器来访问和更新共享的数据模型。struct ContentView: View {
@EnvironmentObject var myDataModel: MyDataModel
var body: some View {
VStack {
Text(myDataModel.myVariable)
Button(action: {
// 更新共享变量
myDataModel.myVariable = "New Value"
}) {
Text("Update Variable")
}
}
}
}
EnvironmentObject
变量,我们可以使用@EnvironmentObject
属性包装器来访问和更新共享的数据模型。struct MyView: View {
@EnvironmentObject var myDataModel: MyDataModel
var body: some View {
// ...
}
}
struct MyView_Previews: PreviewProvider {
static var previews: some View {
MyView()
.environmentObject(MyDataModel())
}
}
// 在协调器类中更新EnvironmentObject变量
class MyCoordinatorClass: NSObject, SomeDelegate {
@EnvironmentObject var myDataModel: MyDataModel
func updateVariable() {
myDataModel.myVariable = "Updated Value"
}
}
这样,我们就可以通过协调器类更新EnvironmentObject
变量。请注意,为了使EnvironmentObject
在协调器类中可用,我们需要在视图的预览中手动提供EnvironmentObject
的实例。
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