【发布时间】:2020-01-06 22:35:10
【问题描述】:
找不到允许我获取所有对象的 NSPredicate 语法,除了一个给定的对象
fetchRequest.predicate = NSPredicate(format: "SELF != %@", setting.objectID)
我的实体没有任何存储的 ID。在 cmets 的某处发现了该语法,但它不起作用:
Generic parameter 'Subject' could not be inferred
任何想法如何过滤除一个给定对象之外的所有对象,而不过滤多个属性?
这是我的观点(使用 SwiftUI):
struct SettingsChoiseView: View {
@Binding var actualSetting: Settings
@Environment(\.managedObjectContext) var moc: NSManagedObjectContext
@FetchRequest var avalibleSettings: FetchedResults<Settings>
init(setting: Binding<Settings>) {
let fetchRequest: NSFetchRequest< Settings> = Settings.fetchRequest()
fetchRequest.sortDescriptors = [NSSortDescriptor(keyPath: \ Settings.name, ascending: true),
NSSortDescriptor(keyPath: \ Settings.height, ascending: true)]
fetchRequest.predicate = NSPredicate(format: "!(name = %@ && height == %d)", setting.name.wrappedValue, setting.height.wrappedValue)
self._avalibleSettings = FetchRequest(fetchRequest:fetchRequest)
}
var body: some View{
...
}
}
Settings 是 NSManagedObject,具有属性名称和高度。
【问题讨论】:
-
如何初始化
fetchRequest? -
@pbasdf 更新帖子
标签: core-data swiftui nspredicate