MvvmCross-MvxBind无法正确绑定 [英] MvvmCross - MvxBind not bind properly

问题描述

在我的viewmodelA中，我有一个属性，当我单击fragmentA.axml中的按钮时，我将执行Mvxbind并更改屏幕，并显示viewmodelB，并且我发送了一个http请求，并且得到了预期的响应.这完全可以按照我希望的方式工作.但是问题是，我似乎可以在我的fragmentB.axml页面(someNumber和状态)中显示该响应.谁能帮我解决这个问题.谢谢！！

In my viewmodelA, I have a property that when the button from my fragmentA.axml is clicked, I do Mvxbind and the screen changes and it shows viewmodelB and also I send an http request and I am getting response as expected. This works exactly how I want it to work. But the problem is, I can seem to show that response in my fragmentB.axml page (someNumber and status). Can anyone help me out with this problem. Thanks!!

ViewmodelA.cs:

    public MvxCommand SomeCommand
    {
        get
        {
            return new MvxCommand(() => something());
        }
    }
    public async void something()
    {
        ShowViewModel<ViewModelB>();

        SomeService serviceWrapper = new SomeService();
        var model = {//Some Json request};
        var result = await serviceWrapper.SubmitRequestAsync(model);
        SomeResponse response = StaticMethods.DeserializeJson<SomeResponse>(result);

        Status = response.SomeResponse1.Activity[0].Status.Description;
        SomeNumber = response.SomeResponse1.SomeNumber;

        Debug.WriteLine("SomeNumber : " + SomeNumber );
        Debug.WriteLine("Status: " + Status);

    }

    private string _someNumber;
    public string SomeNumber 
    {
        get
        {
            return _someNumber;
        }

        set
        {
            SetProperty(ref _someNumber, value);
            RaisePropertyChanged(() => SomeNumber);
        }
    }

    private string _status;
    public string Status
    {
        get
        {
            return _status;
        }

        set
        {
            SetProperty(ref _status, value);
            RaisePropertyChanged(() => Status);
        }
    }

fragmentA.axml

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Submit"
    android:id="@+id/Submit"
    local:MvxBind="Click SomeCommand" />

fragmentB.axml

<TextView
    android:text="Some Number:"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/SomeNum"
    local:MvxBind="Text SomeNumber "/>
<TextView
    android:text="Status:"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/status"
    local:MvxBind="Text Status"/>

推荐答案

MvvmCross不会对n个视图执行一个ViewModel.只允许1:1关系.

MvvmCross does not do one ViewModel to n Views. Only 1:1 relationships are allowed.

有多种方法可以解决您的问题.

There are various ways to tackle your problem.

1. 在ShowViewModel或新的NavigationService中传递一个对象，该对象描述了ICommand的结果.为此，您需要等待导航，直到请求完成:

1. Pass along an object in ShowViewModel or the new NavigationService which describes your result from ICommand. For this to work, you need to wait navigating until your request is done:

var result = await GetSomeData();
ShowViewModel<ViewModelB>(new { status = Status, number = SomeNumber });

然后在ViewModelB中:

Then in ViewModelB:

public void Init(string status, string number)
{
    Status = status;
    Number = number;
}

然后在该ViewModel中具有用于状态和编号的道具.

Then have props for Status and Number in that ViewModel.

2. 拥有一个在ViewModel之间共享的服务，并保持状态并处理您的其余调用:

2. Have a Service that you share between your ViewModels and have it keep the state and take care of your rest calls:

public class MyService : IMyService
{
    public string Status {get; set;}
    public string Number {get; set;}

    public async Task DoStuff()
    {
    }
}

然后在ViewModelA中将是:

Then in ViewModelA ctor would be:

public ViewModelA(IMyService service)

在您的命令中:

public async void something()
{
    await _service.DoSomething();
    ShowViewModel<ViewModelB>();
}

ViewModelB中的Ctor与ViewModelA类似，只是填充任何道具或使道具直接反映正在使用的东西，例如:

Ctor in ViewModelB would be similar to ViewModelA and just populate whatever props or have the props directly reflect what is in service like:

 public string Status => _service.Status;

这些只是解决此问题的两种方法.

These are just two ways of solving this problem.

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