Question

我的VM中有此代码，它可以正常工作：

public ParamViewModel[] CardChoice { get; set; } = new[] 
    {
        new ParamViewModel { Id = 0, Name = CC.All.ShortText(), IsSelected = false, 
            BackgroundColor="#FFFFFF", TextColor="#999999", BorderColor="#999999" },
        new ParamViewModel { Id = 1, Name = CC.Catg.ShortText(), IsSelected = false, 
            BackgroundColor="#FFFFFF", TextColor="#999999" , BorderColor="#999999" },
    };

我将其更改为此，因为我认为我不应该在VM中填充数据，但似乎无法按预期工作：

VM

public ParamViewModel[] CardChoice { get; set; }

C＃后端

vm.CardChoice = new[] 
    {
        new ParamViewModel { Id = 0,  Name = CC.All.ShortText(),   IsSelected = false, 
            BackgroundColor="#FFFFFF", TextColor="#999999" , BorderColor="#999999" },
        new ParamViewModel { Id = 1,  Name = CC.Catg.ShortText(),  IsSelected = false, 
            BackgroundColor="#FFFFFF", TextColor="#999999" , BorderColor="#999999" }
    };

但是现在在使用此数据作为后端的控件中没有任何内容。我在后端填充数据的方式有问题吗？

Answer 1

按如下所示更改您的VM代码。

在比UI渲染晚的阶段访问属性时，您必须使用INotifyPropertyChanged告知渲染器重新渲染

public class YourVM : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
    }

    private ParamViewModel[] cardChoice;

    public ParamViewModel[] CardChoice
    {
        get { return cardChoice; }
        set 
        { 
            cardChoice = value;
            OnPropertyChanged("CardChoice")
        }
    }
}

为什么不能在ViewModel中声明的后端C＃中填充数组？

1 个答案: