如何在 SwiftUI 中限制 FetchRequest 中的结果数量 [英] How to limit the number of results in a FetchRequest in SwiftUI

问题描述

如何在向 CoreData 发送 FetchRequest 时限制检索到的 FetchedResults 的大小?

How can I limit the size of the retrieved FetchedResults when making a FetchRequest to CoreData?

struct ContentView: View {
    var fetchRequest:FetchRequest<Kana>

    init(){
        fetchRequest = FetchRequest<Kana>(entity: Kana.entity(), sortDescriptors: [], predicate: NSPredicate(format: "alphabet == %@", "hiragana"))
    }

    var body: some View {
        List{
            Text("10 Kanas")
            // Display 10 Kanas
        }
    }
}

推荐答案

需要使用对应的初始化器创建FetchRequest和NSFeatchRequest，如下图

You need to create FetchRequest with NSFeatchRequest using corresponding initialiser, as shown below

init() {
    let request: NSFetchRequest<Kana> = Kana.fetchRequest()
    request.fetchLimit = 10
    request.predicate = NSPredicate(format: "alphabet == %@", "hiragana")
    fetchRequest = FetchRequest<Kana>(fetchRequest: request)
}

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