mvvm - OnInitialize 和 OnActivate 不会在 subview 模型上调用

Question

我希望从 Screen 继承的 subview 模型会参与到父屏幕的生命周期中。然而，情况似乎并非如此。例如:

public class ParentViewModel : Screen
{
    public ChildViewModel Child { get; set; }

    public ParentViewModel(ChildViewModel childViewModel)
    {
        this.Child = childViewModel;
    }

    public override void OnInitialize() { // called - as expected }

    public override void OnActivate() { // called - as expected }

    public override void OnDeactivate() { // called - as expected }
}

public class ChildViewModel : Screen
{
    public override void OnInitialize() { // not called - why? }

    public override void OnActivate() { // not called - why? }

    public override void OnDeactivate() { // not called - why? }
}

是否可以让子屏幕参与父屏幕的生命周期？

Answer 1

似乎这种行为不是默认的，必须告诉父级使用 ConductWith 来“引导” subview 模型。方法，如下:

public class ParentViewModel : Screen
{
    public ChildViewModel Child { get; set; }

    public ParentViewModel(ChildViewModel childViewModel)
    {
        this.Child = childViewModel;

        Child.ConductWith(this);
    }
}

这确保 ChildViewModel 将与父级同时初始化、激活和停用。 ActivateWith如果您只需要初始化/激活 child ，则可以使用方法。