我有一个主窗口,将Usercontrol作为ContentControl主机托管。我想要的是,在按钮点击(存在于第一个Usercontrol中)动态更改usercontrol到另一个用户控件。
目前我在主窗口资源中创建了一个DataTemplate资源,该资源由用户控件的相应ViewModel组成
<DataTemplate DataType="{x:Type Tube:ViewModel1}" >
<Tube:View1/>
</DataTemplate>
<DataTemplate DataType="{x:Type Tube1:ViewModel2}">
<Tube2:View2/>
</DataTemplate>
<DataTemplate DataType="{x:Type Tube:ViewModel1}" >
<Tube:View1/>
</DataTemplate>
<DataTemplate DataType="{x:Type Tube1:ViewModel2}">
<Tube2:View2/>
</DataTemplate>
我想在view1中点击按钮时从View1更改为view2。那么我应该如何在ViewModel1(US1 viewModel)中更改为US2
我目前正在开发MVVM灯。
我有一个服务定位器,它具有每个VM的注册实例。问题是如何指向VM1中的VM2实例。
欢迎任何帮助!!!!!
答案 0 :(得分:2)
将您的Window视为shell并使用MvvmLight的Messenger将消息发送到您的shell以交换视图。
例如:
MainWindow.xaml
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication1"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:MainWindowViewModel></local:MainWindowViewModel>
</Window.DataContext>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="20"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Button Grid.Row="0" Grid.Column="0" Command="{Binding ChangeFirstViewCommand}">Change View #1</Button>
<Button Grid.Row="0" Grid.Column="1" Command="{Binding ChangeSecondViewCommand}">Change View #2</Button>
<ContentControl Grid.Row="1" Grid.ColumnSpan="2" Content="{Binding ContentControlView}"></ContentControl>
</Grid>
</Window>
MainWindowViewModel.cs
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
using GalaSoft.MvvmLight.Messaging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
namespace WpfApplication1
{
public class MainWindowViewModel : ViewModelBase
{
private FrameworkElement _contentControlView;
public FrameworkElement ContentControlView
{
get { return _contentControlView; }
set
{
_contentControlView = value;
RaisePropertyChanged("ContentControlView");
}
}
public MainWindowViewModel()
{
Messenger.Default.Register<SwitchViewMessage>(this, (switchViewMessage) =>
{
SwitchView(switchViewMessage.ViewName);
});
}
public ICommand ChangeFirstViewCommand
{
get
{
return new RelayCommand(() =>
{
SwitchView("FirstView");
});
}
}
public ICommand ChangeSecondViewCommand
{
get
{
return new RelayCommand(() =>
{
SwitchView("SecondView");
});
}
}
public void SwitchView(string viewName)
{
switch (viewName)
{
case "FirstView":
ContentControlView = new FirstView();
ContentControlView.DataContext = new FirstViewModel() { Text = "This is the first View" };
break;
default:
ContentControlView = new SecondView();
ContentControlView.DataContext = new SecondViewModel() { Text = "This is the second View" };
break;
}
}
}
}
FirstView.xaml
<UserControl x:Class="WpfApplication1.FirstView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<StackPanel>
<Label>This is the second view</Label>
<Label Content="{Binding Text}" />
<Button Command="{Binding ChangeToSecondViewCommand}">Change to Second View</Button>
</StackPanel>
</UserControl>
FirstViewModel.cs
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
using GalaSoft.MvvmLight.Messaging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
namespace WpfApplication1
{
public class FirstViewModel : ViewModelBase
{
private string _text;
public string Text
{
get { return _text; }
set
{
_text = value;
RaisePropertyChanged("Text");
}
}
public ICommand ChangeToSecondViewCommand
{
get
{
return new RelayCommand(() =>
{
Messenger.Default.Send<SwitchViewMessage>(new SwitchViewMessage { ViewName = "SecondView" });
});
}
}
}
}
SecondView.xaml
<UserControl x:Class="WpfApplication1.SecondView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<StackPanel>
<Label>This is the second view</Label>
<Label Content="{Binding Text}" />
<Button Command="{Binding ChangeToFirstViewCommand}">Change to First View</Button>
</StackPanel>
</UserControl>
SecondViewModel.cs
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
using GalaSoft.MvvmLight.Messaging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
namespace WpfApplication1
{
public class SecondViewModel : ViewModelBase
{
private string _text;
public string Text
{
get { return _text; }
set
{
_text = value;
RaisePropertyChanged("Text");
}
}
public ICommand ChangeToFirstViewCommand
{
get
{
return new RelayCommand(() =>
{
Messenger.Default.Send<SwitchViewMessage>(new SwitchViewMessage { ViewName = "FirstView" });
});
}
}
}
}
SwitchViewMessage.cs
namespace WpfApplication1
{
public class SwitchViewMessage
{
public string ViewName { get; set; }
}
}
答案 1 :(得分:1)
在MainViewModel中创建一个属性,例如“DisplayViewModel”,其中包含vm1和vm2的基本类型。
private MyViewModelBase _displayViewModel;
public MyViewModelBase DisplayViewModel
{
get { return _displayViewModel; }
set
{
_displayViewModel = value;
OnPropertyChanged("DisplayViewModel"); // Raise PropertyChanged
}
}
在MainView.xaml中插入一个绑定到DisplayViewModelProperty的ContentControl:
<ContentControl Content="{Binding DisplayViewModel}" />
在Button-Command上,您可以使用另一个ViewModel通过Setter修改DisplayProperty,并结合DataTemplates,ContentControl显示的UserControl应根据新设置的ViewModel-Type更改为View。
private void MyButtonCommand()
{
DisplayViewModel = new ViewModel2();
}