Caliburn Micro TabItem單擊事件沒有找到方法的目標

Question

我正在使用Caliburn Micro從我的視圖中的MenuItem調用ViewModel中的方法。但是每次當我點擊MenuItem時，我都會遇到異常：找不到方法SuggestPresent的目標。我嘗試了不同的方式來調用我的ViewModel方法，但目前爲止沒有任何工作。我怎樣才能使它工作？

MainView.xaml

<Controls:MetroWindow x:Class="Expreriment.Views.MainView" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    xmlns:model="clr-namespace:Expreriment.ViewModels" 
    xmlns:vc="clr-namespace:Expreriment.Converters" 
    xmlns:local="clr-namespace:Expreriment" 
    xmlns:Controls="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro" 
    xmlns:cal="http://www.caliburnproject.org" 
    xmlns:sys="clr-namespace:System;assembly=mscorlib" 
    mc:Ignorable="d" 
    d:DataContext="{x:Type model:MainViewModel}" 
    Title="{Binding WindowTitle}" 
    x:Name="Window" 
    Height="500" Width="800"> 

<Controls:MetroWindow.Resources> 
    <vc:FindResourceFromString x:Key="FindResourceFromStringConverter" /> 
</Controls:MetroWindow.Resources> 

<Grid> 
    <Grid.ColumnDefinitions> 
     <ColumnDefinition Width="Auto" /> 
     <ColumnDefinition Width="*" /> 
    </Grid.ColumnDefinitions> 

    <Controls:Flyout Header="Menu" Position="Left" Width="175" IsOpen="True" Name="menuFlyout" Grid.Column="0"> 
     <Menu ItemsSource="{Binding enumData}" DisplayMemberPath="Enum"> 
      <Menu.ItemsPanel> 
       <ItemsPanelTemplate> 
        <VirtualizingStackPanel Orientation="Vertical"/> 
       </ItemsPanelTemplate> 
      </Menu.ItemsPanel> 
      <MenuItem Header="Category" ItemsSource="{Binding EnumData}" DisplayMemberPath="Enum"> 
       <MenuItem.ItemContainerStyle> 
        <Style TargetType="MenuItem"> 
         <Setter Property="IsCheckable" Value="True"/> 
         <Setter Property="IsChecked" Value="{Binding IsChecked, Mode=TwoWay}"/> 
         <Setter Property="StaysOpenOnClick" Value="True"/> 
        </Style> 
       </MenuItem.ItemContainerStyle> 
      </MenuItem> 
      <MenuItem cal:Action.TargetWithoutContext="{Binding ElementName=Window, Path=Datacontext}" cal:Message.Attach="SuggestPresent" Header="Suggest present"> 
       <MenuItem.Icon> 
        <Image Height="25" Width="25" Source="/Resources/Images/Plus.png"/> 
       </MenuItem.Icon> 
      </MenuItem> 
     </Menu> 
    </Controls:Flyout> 

    <Controls:FlipView Grid.Column="1" ItemsSource="{Binding Gifts}" SelectedItem="{Binding Path=SelectedGift, Mode=TwoWay}" BannerText="{Binding SelectedGift.Name}"> 
     <Controls:FlipView.ItemTemplate> 
      <DataTemplate> 
       <Grid Background="#2E8DEF"> 
        <Rectangle Margin="0, 0, 10, 0" Width="100" Height="100"> 
         <Rectangle.Fill> 
          <VisualBrush Visual="{Binding Icon, Converter={StaticResource FindResourceFromStringConverter}}" /> 
         </Rectangle.Fill> 
        </Rectangle> 
       </Grid> 
      </DataTemplate> 
     </Controls:FlipView.ItemTemplate> 
    </Controls:FlipView> 
</Grid> 

MainViewModel.cs

using Caliburn.Micro; 
using Expreriment.Model; 
using System; 
using System.Collections.ObjectModel; 
using System.ComponentModel.Composition; 
using System.Linq; 

namespace Expreriment.ViewModels 
{ 
    [Export(typeof(MainViewModel))] 
    public class MainViewModel : PropertyChangedBase 
    { 
     //added 
     private readonly IWindowManager _windowManager; 

     [ImportingConstructor] 
     public MainViewModel(IWindowManager windowManager) 
     { 
      _windowManager = windowManager; 
     } 

     private void SuggestPresent() 
     { 
      _windowManager.ShowWindow(new SuggestPresentViewModel(_windowManager)); 
     } 
     //end 

     private const string WindowTitleDefault = "Present Presenter"; 

     private string _windowTitle = WindowTitleDefault; 

     public string WindowTitle 
     { 
      get { return _windowTitle; } 
      set 
      { 
       _windowTitle = value; 
       NotifyOfPropertyChange(() => WindowTitle); 
      } 
     } 

     public ObservableCollection<EnumData> _enumData = new ObservableCollection<EnumData>(Enum.GetNames(typeof(CategoryType)).Select(s => new EnumData { Enum = s, IsChecked = false })); 
     public ObservableCollection<EnumData> EnumData 
     { 
      get { return _enumData; } 
      set 
      { 
       _enumData = value; 
       NotifyOfPropertyChange(() => EnumData); 
      } 
     } 

     public ObservableCollection<Gift> _gifts = new ObservableCollection<Gift>(GiftAction.GetGifts()); 

     public ObservableCollection<Gift> Gifts 
     { 
      get { return _gifts; } 
      set 
      { 
       _gifts = value; 
       NotifyOfPropertyChange(() => Gifts); 
      } 
     } 

     public Gift _selectedGift = new Gift(); 
     public Gift SelectedGift 
     { 
      get { return _selectedGift; } 
      set 
      { 
       _selectedGift = value; 
       NotifyOfPropertyChange(() => SelectedGift); 
      } 
     } 
    } 
} 

我嘗試以下行沒有成功：

"SuggestPresent($orignalsourcecontext)" 

cal:Message.Attach="SuggestPresent()" cal:Action.TargetWithoutContext="{Binding Path=PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}" 

cal:Action.TargetWithoutContext="{Binding ElementName=Window, Path=Datacontext}" cal:Message.Attach="SuggestPresent" 

Answer 1

方法SuggestPresent NE編者爲public。根據所提供的示例，它目前是private。框架在綁定到視圖模型時搜索公共方法和屬性。

public void SuggestPresent() 
{ 
    _windowManager.ShowWindow(new SuggestPresentViewModel(_windowManager)); 
}