请参考以下代码块。对于这些代码块,我尝试在子组件中访问父组件的值,但是子组件总是返回空值。
Component.razor
:
<Parent TValue="TreeData">
<Child TValue="TreeNode<TreeData>"></Child>
</Parent>
@code {
public class TreeData
{
public string Value { get; set; }
}
public class TreeNode<TreeData>
{
public int Count { get; set; }
}
}
Parent.razor
:
<CascadingValue Value="@this">
@ChildContent
</CascadingValue>
Child.razor
:
@code {
[CascadingParameter]
private Parent<TValue> ParentObj { get; set; }
protected override async Task OnInitializedAsync()
{
await base.OnInitializedAsync();
//Parent obj always returns the null value
ParentObj?.UpdateChildProperties("UpdateData", this);
}
}
@typeparam TValue
,我假设它必须在父类和子类中存在。 - undefined