WPF MVVM框架 Caliburn.Micro的Action绑定

通过命名约定来绑定Action
View

<Window x:Class="WpfApp1.Views.AboutView"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"mc:Ignorable="d" WindowStartupLocation="CenterScreen" SizeToContent="WidthAndHeight"xmlns:i="http://schemas.microsoft.com/xaml/behaviors"xmlns:cal="http://www.caliburnproject.org"xmlns:conv="clr-namespace:WpfApp1.Converters"Title="About"  MinHeight="800" MinWidth="800" WindowStyle="SingleBorderWindow"><Grid><Button Name="OK" Width="100" Height="80" Content="Click"/></Grid>
</Window>

ViewModel


using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using Caliburn.Micro;
using WpfApp1.Models;namespace WpfApp1.ViewModels
{public class AboutViewModel{public void Ok(){MessageBox.Show("Test");}}
}

点击View中的按钮时，可以把Clicked事件的处理函数导航到ViewModel中的OK方法中，其原因是命名规则遵守了Caliburn.Micro的约定，即View中的Button名称叫OK，ViewModel中有一个OK的方法。

通过Message.Attach来设置Event Handler
View

<Window x:Class="WpfApp1.Views.AboutView"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"mc:Ignorable="d" WindowStartupLocation="CenterScreen" SizeToContent="WidthAndHeight"xmlns:i="http://schemas.microsoft.com/xaml/behaviors"xmlns:cal="http://www.caliburnproject.org"xmlns:conv="clr-namespace:WpfApp1.Converters"Title="About"  MinHeight="800" MinWidth="800" WindowStyle="SingleBorderWindow"><Grid><Button cal:Message.Attach="OK" Width="100" Height="80" Content="Click"/></Grid>
</Window>

ViewModel部分同上
就其原因是Caliburn.Micro内部有维护一个消息触发器，xaml中的写法相当于注册到了消息中心，当用户点击按钮时，消息中心会匹配到对应的ViewModel中同名的函数作为Handler

下面用一个完整的Demo展示，如何绑定到更复杂的事件、如何传参数
View

<Window x:Class="WpfApp1.Views.AboutView"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"mc:Ignorable="d" WindowStartupLocation="CenterScreen" SizeToContent="WidthAndHeight"xmlns:i="http://schemas.microsoft.com/xaml/behaviors"xmlns:cal="http://www.caliburnproject.org"xmlns:conv="clr-namespace:WpfApp1.Converters"Title="About"  MinHeight="800" MinWidth="800" WindowStyle="SingleBorderWindow"><Window.Resources><conv:Color2SolidBrushConverter x:Key="colorConverter"/><DataTemplate x:Key="combItem" DataType="{x:Type ComboBoxItem}"><StackPanel Orientation="Horizontal" Width="100"  Height="20"><Rectangle Width="20" Height="20" Fill="{Binding Color,Converter={StaticResource colorConverter}}"/><TextBlock Text="{Binding Name}" Margin="5,0,0,0"/></StackPanel></DataTemplate></Window.Resources><Grid><Grid.ColumnDefinitions><ColumnDefinition Width="200"/><ColumnDefinition Width="600"/></Grid.ColumnDefinitions><Grid Grid.Column="0"><ComboBox Name="cmb" ItemsSource="{Binding Colors}" SelectedItem="{Binding SelectedColor}" Width="100" Height="28" ItemTemplate="{StaticResource combItem}"cal:Message.Attach="[Event SelectionChanged] = [Action OnSelectedColorChanged($eventArgs)]"/></Grid><Grid Grid.Column="1"><Rectangle Fill="{Binding SelectedColor.Color,Converter={StaticResource colorConverter}}"/></Grid></Grid>
</Window>

ViewModel

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.using System.Collections.ObjectModel;
using System.Windows.Controls;
using Caliburn.Micro;
using WpfApp1.Models;namespace WpfApp1.ViewModels
{public class AboutViewModel:Screen{private ColorModel _selectedColor;public ObservableCollection<ColorModel> Colors { get; set; }public ColorModel SelectedColor{get => _selectedColor;set{_selectedColor = value;NotifyOfPropertyChange(nameof(SelectedColor));}}public void OnSelectedColorChanged(SelectionChangedEventArgs e){ }public AboutViewModel(){Colors=new ObservableCollection<ColorModel>();Colors.Add(new ColorModel("Red","Red"));Colors.Add(new ColorModel("Green","Green"));Colors.Add(new ColorModel("Blue","Blue"));Colors.Add(new ColorModel("White","White"));}}
}

Model

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.using Caliburn.Micro;namespace WpfApp1.Models
{public class ColorModel : Screen{private string _color;private string _name;public ColorModel(string color, string name){_color = color;_name = name;}public string Color{get => _color;set{if (!string.IsNullOrEmpty(value)){_color = value;NotifyOfPropertyChange(nameof(Color));}}}public string Name{get => _name;set{if (!string.IsNullOrEmpty(_name)){_name = value;NotifyOfPropertyChange(nameof(Name));}}}}
}

Converter

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.using System.Globalization;
using System.Windows.Data;
using System.Windows.Media;namespace WpfApp1.Converters
{public class Color2SolidBrushConverter : IValueConverter{public object Convert(object value, Type targetType, object parameter, CultureInfo culture){if (value != null){if (value.ToString() == "Red"){return new SolidColorBrush(Colors.Red);}else if(value.ToString() == "Green"){return new SolidColorBrush(Colors.Green);}else if (value.ToString() == "Blue"){return new SolidColorBrush(Colors.Blue);}else{return new SolidColorBrush(Colors.Black);}}return default;}public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture){return default;}}
}