WPF中模板选择和DataContext的一些使用

如图样：

View结构

MainView（MainViewModel）
|---Guide1View(Guide1ViewModel)
|---Guide2View(Guide2ViewModel)
　　|---Guide2_1View1(Guide2_1ViewModel)
　　|---Guide2_1View2(Guide2_1ViewModel)

ViewModel实例结构

Main（ViewModelViewModel）
|---CurrentViewModel（GuidePageViewModelBase）
|---PageViewModelList（ObservableCollection<GuidePageViewModelBase>）
　　|---Guide1（Guide1ViewModel）
　　|---Guide2（Guide2ViewModel）
　　　　|---LVM1（LViewModel）
　　　　|---LVM2（LViewModel）

1、通过ContentControl显示选中的视图模型对应的视图：

<ContentControl Content="{Binding CurrentViewModel}">
    <ContentControl.Resources>
        <DataTemplate DataType="{x:Type viewmodel:Guide1ViewModel}">
            <view:Guide1View/>
        </DataTemplate>
        <DataTemplate DataType="{x:Type viewmodel:Guide2ViewModel}">
            <view:Guide2View/>
        </DataTemplate>
    </ContentControl.Resources>
</ContentControl>

2、Guide2_1View作为一个多次使用的控件，对应一个LViewModel，设置自己的DataContext（这里的背景是该视图的使用个数确定的。当然也可以用ListBox代替）：

<view:Guide2_1View DataContext="{Binding Path=DataContext.LVM1,RelativeSource={RelativeSource AncestorType={x:Type UserControl}}}" />
<view:Guide2_1View DataContext="{Binding Path=DataContext.LVM2,RelativeSource={RelativeSource AncestorType={x:Type UserControl}}}" />

完整代码：

ViewModel:

using GalaSoft.MvvmLight;

namespace WPF_NestedVMAndView.ViewModel
{
    public class MainViewModel : ViewModelBase
    {
        public MainViewModel()
        {
            PageViewModelList = new ObservableCollection<GuidePageViewModelBase>()
            {
                new Guide1ViewModel(),
                new Guide2ViewModel(),
            };
            CurrentViewModel = PageViewModelList[1];
        }

        public const string CurrentViewModelPropertyName = "CurrentViewModel";
        private GuidePageViewModelBase _currentViewModel;
        public GuidePageViewModelBase CurrentViewModel
        {
            get
            {
                return _currentViewModel;
            }

            set
            {
                if (_currentViewModel == value)
                    return;

                _currentViewModel = value;
                RaisePropertyChanged(CurrentViewModelPropertyName);
            }
        }

        public const string PageViewModelListPropertyName = "PageViewModelList";
        private ObservableCollection<GuidePageViewModelBase> _pageViewModelList;
        public ObservableCollection<GuidePageViewModelBase> PageViewModelList
        {
            get
            {
                return _pageViewModelList;
            }

            set
            {
                if (_pageViewModelList == value)
                    return;

                _pageViewModelList = value;
                RaisePropertyChanged(PageViewModelListPropertyName);
            }
        }
    }

    public class GuidePageViewModelBase : ViewModelBase
    {
        public GuidePageViewModelBase(string name)
        {
            Name = name;
        }

        public const string NamePropertyName = "Name";
        private string _name;
        public string Name
        {
            get
            {
                return _name;
            }

            set
            {
                if (_name == value)
                    return;

                _name = value;
                RaisePropertyChanged(NamePropertyName);
            }
        }
    }

    public class Guide1ViewModel : GuidePageViewModelBase
    {
        public Guide1ViewModel()
            : base("Guide1")
        {

        }
    }

    public class Guide2ViewModel : GuidePageViewModelBase
    {
        public Guide2ViewModel() : base("Guide2")
        {
            LVM1 = new LViewModel()
            {
                Text = "LVM1",
            };
            LVM2 = new LViewModel()
            {
                Text = "LVM2",
            };
        }

        public const string LVM1PropertyName = "LVM1";
        private LViewModel _lvm1;
        public LViewModel LVM1
        {
            get
            {
                return _lvm1;
            }

            set
            {
                if (_lvm1 == value)
                    return;

                _lvm1 = value;
                RaisePropertyChanged(LVM1PropertyName);
            }
        }

        public const string LVM2PropertyName = "LVM2";
        private LViewModel _lvm2;
        public LViewModel LVM2
        {
            get
            {
                return _lvm2;
            }

            set
            {
                if (_lvm2 == value)
                    return;

                _lvm2 = value;
                RaisePropertyChanged(LVM2PropertyName);
            }
        }
    }

    public class LViewModel : ViewModelBase
    {
        public const string TextPropertyName = "Text";
        private string _text;
        public string Text
        {
            get
            {
                return _text;
            }

            set
            {
                if (_text == value)
                    return;

                _text = value;
                RaisePropertyChanged(TextPropertyName);
            }
        }
    }
}

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