使用MvvmCross ShowViewModel传递复杂的导航参数 [英] Passing complex navigation parameters with MvvmCross ShowViewModel

问题描述

即使使用此处指定的配置的MvxJsonNavigationSerializer，我的复杂类型也不会从Show传递给Init方法，

My complex type wouldn't pass from Show to Init method even with configured MvxJsonNavigationSerializer as specified here Custom types in Navigation parameters in v3

public class A
{
 public string String1 {get;set;}
 public string String2 {get;set;}
 public B ComplexObject1 {get;set;}
}

public class B
{
 public double Double1 {get;set;}
 public double Double2 {get;set;}
}

当我将对象A的实例传递给ShowViewModel方法时，我使用String1& String2正确反序列化，但CopmlexObject1为空.

When I pass instance of object A to ShowViewModel method I receive this object with String1 & String2 deserialized correctly but CopmlexObject1 is null.

如何处理复杂对象MvvmCross序列化?

How to deal with complex object MvvmCross serialization?

推荐答案

我认为先前的答案中可能包含一些小怪兽-会记录为问题:/

I believe there may be some gremlins in that previous answer - will log as an issue :/

还有其他可能的途径仍然可以使用Json和框架的覆盖部分来实现这种类型的复杂可序列化对象导航，但是实际上我认为仅使用您自己的BaseViewModel进行序列化和反序列化可能会更好-例如使用序列化代码，例如:

There are other possible routes to achieve this type of complex serializable object navigation still using Json and overriding parts of the framework, but actually I think that it might be better to just use your own BaseViewModel's to do serialization and deserialization - e.g. use serialization code like:

public class BaseViewModel
    : MvxViewModel
{
    private const string ParameterName = "parameter";

    protected void ShowViewModel<TViewModel>(object parameter)
        where TViewModel : IMvxViewModel
    {
        var text = Mvx.Resolve<IMvxJsonConverter>().SerializeObject(parameter);
        base.ShowViewModel<TViewModel>(new Dictionary<string, string>()
            {
                {ParameterName, text}
            });
    }
}

具有反序列化功能，例如:

with deserialization like:

public abstract class BaseViewModel<TInit>
    : MvxViewModel
{
    public void Init(string parameter)
    {
        var deserialized = Mvx.Resolve<IMvxJsonConverter>().DeserializeObject<TInit>(parameter);
        RealInit(deserialized);
    }

    protected abstract void RealInit(TInit parameter);
}

然后是一个像这样的viewModel:

then a viewModel like this:

public class FirstViewModel
    : BaseViewModel
{
    public IMvxCommand Go
    {
        get
        {
            return new MvxCommand(() =>
                {
                    var parameter = new A()
                        {
                            String1 = "Hello",
                            String2 = "World",
                            ComplexObject = new B()
                                {
                                    Double1 = 42.0,
                                    Double2 = -1
                                }
                        };
                    ShowViewModel<SecondViewModel>(parameter);
                });
        }
    }
}

可以导航至以下内容:

public class SecondViewModel
    : BaseViewModel<A>
{
    public A A { get; set; }

    protected override void RealInit(A parameter)
    {
        A = parameter;
    }
}

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