我在预览一个看起来很简单的结构时遇到了问题。客户是核心数据实体:
struct CustomerDetailView: View {
@Environment(.managedObjectContext) var moc
@State var showNewCustomer = false
var customer: Customer
var body: some View {
我试过几乎所有不起作用的东西,包括这个:
struct CustomerDetail_Previews: PreviewProvider {
static var previews: some View {
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
return
CustomerDetailView(customer: --Not sure what works here-- ).environment(.managedObjectContext, context)
}
}
我尝试过static let customer=customer((,这样我就可以在最后一行使用一个customer变量,但这并没有帮助。
Preview为应用程序使用不同的容器,因此您可以创建新的Customer
,如
struct CustomerDetail_Previews: PreviewProvider {
static var previews: some View {
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
return
CustomerDetailView(customer: Customer(context: context))
.environment(.managedObjectContext, context)
}
}