ObservableObject var 未在文本上更新

Question

我想在 currentStatus 更改时更新 contentview 文本，但是当运行 MLModel 加载模型时，它打印“正在加载资源...”，但 currentStatus 没有更新 ContentView 中的文本，我尝试添加 DispatchQueue.main.async，但是还是不行

ContentView.swift

struct ContentView: View {
    @StateObject var model = Content.ViewModel()
    
    var body: some View {
        VStack {
            Text(model.currentStatus)
                .multilineTextAlignment(.center)
                .padding(.horizontal)
        }
        .padding()
        .onAppear {
            model.inited()
        }
    }
}

ContentModel.swift

class ContentModel: ObservableObject {
    @Published var currentStatus: String = "init..."
    func inited() {
        currentStatus = "loading resources..."
        print("currentStatus: \(self.currentStatus)")
        guard let path = Bundle.main.path(forResource: "Unet", ofType: "mlmodelc", inDirectory: "split") else {
            fatalError("Fatal error: failed to find the CoreML model.")
        }
        let resourceURL = URL(fileURLWithPath: path)
        let config = MLModelConfiguration()
        config.computeUnits = .cpuAndGPU
        
        var loadedModel: MLModel?
        do {
            loadedModel = try MLModel(contentsOf: resourceURL, configuration: config)
        } catch {
            print(error)
        }
        currentStatus = "complete"
        print("currentStatus: \(self.currentStatus)")
    }
}

Answer 1

应该是@StateObject，而不是@ObservedObject。并考虑将 ContentModel 定义放入 Model 的扩展中，而不是

 @ObservedObject var model = ContentModel()

你将拥有：

 @StateObject var model = Content.ViewModel()

我相信它使代码更具可读性，但是YMMV。