我有两个 View :MainView
和 DetailView
。我有一个要显示的项目列表,当用户选择一个项目时,我将项目属性传递给 DetailViewModel
并且用户可以更新这些值。
到目前为止一切正常,但我想知道如何将更新后的值传递回 MainViewModel
?
MainViewModel.cs
public MainViewModel SelectedItem
{
get { return _selectedItem; }
set
{
_selectedItem = value;
ShowViewModel<DetailViewModel>(
new DetailViewModel.Parameter
{
Date = Date,
Age = _selectedItem.Age,
Category = _selectedItem.Category,
Discount = _selectedItem.Discount,
}
);
RaisePropertyChanged(() => SelectedItem);
}
}
DetailViewModel.cs
public class DetailViewModel: MvxViewModel
{
public double Age { get; set; }
public double Category { get; set; }
public double Discount { get; set; }
public class Parameter
{
public DateTime Date { get; set; }
public double Age { get; set; }
public int Category{ get; set; }
public double Discount { get; set; }
}
public void Init(Parameter param)
{
Age = param.Age;
Category = param.Category;
Discount = param.Discount ;
}
}
最佳答案
在 ViewModels
之间传递变量的一种方法是基于 Messenger
的解决方案。
可以在 NuGet 中找到 MvvmCross Messenger。
主视图模型
private readonly IMvxMessenger _messenger;
private readonly MvxSubscriptionToken _token;
public MainViewModel(IMvxMessenger messenger) {
_messenger = messenger;
_token = messenger.Subscribe<SelectedItemMessage>(OnMessageReceived);;
}
private void OnMessageReceived(SelectedItemMessage obj)
{
SelectedItem = obj.SelectedItem;
}
DetailViewModel
private readonly IMvxMessenger _messenger;
public DetailViewModel(IMvxMessenger messenger) {
_messenger = messenger;
}
public void YourUpdateMethod() {
var message = new SelectedItemMessage(this, SelectedItem); //SelectedItem assumed it is a ViewModel property.
_messenger.Publish(message, typeof(SelectedItemMessage));
}
SelectedItemMessage
public class SelectedItemMessage : MvxMessage
{
public SelectedItemMessage(object sender, SelectedItem selectedItem) : base(sender)
{
SelectedItem = selectedItem;
}
public SelectedItem SelectedItem { get; set; }
}
看看http://slodge.blogspot.nl/2013/05/n9-getting-message-n1-days-of-mvvmcross.html MvvmCross Messenges
的完整指南。
在消息中使用年龄和类别进行编辑
public SelectedItemMessage(object sender, double age, int category) : base(sender)
{
Age = age;
Category = category;
}
public double Age { get; set; }
public int Category{ get; set; }
}
更改 MainViewModel OnMessageReceived 方法
private void OnMessageReceived(SelectedItemMessage obj)
{
Age = obj.Age;
Category= obj.Category;
}
关于c# - 将参数从 Detail 传递到 MVVMCross 中的 MainViewModel,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36731516/