Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架
openkk
13年前
<p>本章节，我将通过示例介绍如何搭建mvvmlight开发环境。示例中的我会针对wpf代码进行介绍，SL下有区别的地方我会注明，下载示例中会同时包含WPF和SL源代码，但是只会提供VS2010版本的示例程序。</p> <p>前提条件：按照前一章节安装的模板和代码片段，或者下载 MVVM Light Toolkit V3</p> <p>开发环境：VS2010/Blend4</p> <p>为了方便大家了解框架结构，我将不使用mvvm项目模板，而是从空白项目开始创建mvvm light项目，下面将以两种使用mvmmlight框架的方式进行说明(以下示例针对WPF，SL操作步骤跟WPF基本一样，不做过多说明，大家可以在文章最后下载代码对照阅读)：</p> <p>1、在VS2010中，文件\新建\WPF/SilverLight应用程序项目，项目名称MvvmlightDataBinding.SL4/MvvmlightDataBinding.WPF4</p> <p>2、添加mvvmlight引用，如果使用模板创建，会自动生成引用，而这里我们需要自己添加，这里我将MVVM Light Toolkit V3的源代码附到了示例中，因此，直接添加项目引用就可以了，如果要支持Blend的功能，还需要添加 System.Windows.Interactivity.dll引用，如果安装了Blend，在.net引用列表中能找到，没有安装Blend，在示例中解决方案目录\Assemblies\GalaSoft.MvvmLight\External中能找到，添加后引用列表如下：</p> <p></p> <img title="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" border="0" alt="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" src="https://simg.open-open.com/show/b70f98aa8859abfc238a25ec1f96ef34.jpg" width="367" height="620" /> <p> </p> <p>3、在解决方案浏览器中，右键项目名称，添加新文件夹，文件夹名称为ViewModel</p> <p>4、在解决方案浏览器中，右键项目名称，添加新文件夹，文件夹名称为View</p> <p>5、为MainWindow添加ViewModel，在解决方案浏览器中，右键ViewModel文件夹，添加新类，类名称为MainViewModel，如果安装了mvvmlight模板，选择类模板为MvvmViewModel</p> <p></p> <p> </p> <img style="width:636px;height:356px;" title="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" border="0" alt="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" src="https://simg.open-open.com/show/530d010b1c9e03ae4f652f748f002c7b.jpg" /> <p> </p> <p>自动创建的代码如下：</p> <div> <span style="color:#0000ff;">using</span> GalaSoft.MvvmLight; <br /> <br /> <span style="color:#0000ff;">namespace</span> MvvmlightDataBinding.WPF4.ViewModel <br /> { <br /> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">class</span> MainViewModel : ViewModelBase <br /> { <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Initializes a new instance of the MainViewModel class.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> <span style="color:#0000ff;">public</span> MainViewModel() <br /> { <br /> <span style="color:#008000;">////if (IsInDesignMode)</span> <br /> <span style="color:#008000;">////{</span> <br /> <span style="color:#008000;">//// // Code runs in Blend --> create design time data.</span> <br /> <span style="color:#008000;">////}</span> <br /> <span style="color:#008000;">////else</span> <br /> <span style="color:#008000;">////{</span> <br /> <span style="color:#008000;">//// // Code runs "for real": Connect to service, etc...</span> <br /> <span style="color:#008000;">////}</span> <br /> } <br /> <br /> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">override</span> <span style="color:#0000ff;">void</span> Cleanup() <br /> { <br /> <span style="color:#008000;">// Clean own resources if needed</span> <br /> <br /> <span style="color:#0000ff;">base</span>.Cleanup(); <br /> } <br /> } <br /> } </div> <p> </p> <p>代码很简单，我去掉了类注释，它是一个框架，继承自ViewModelBase，如果没装类模板，可以直接复制以上代码。</p> <p>6、添加类ViewModelLocator，我们叫它ViewModel加载器，在解决方案浏览器中，右键项目名称，添加新类，类名称为 ViewModelLocator，如果安装了mvvmlight模板，选择类模板为MvvmViewModelLocator，自动创建的代码如下：</p> <div> <span style="color:#0000ff;">namespace</span> MvvmlightDataBinding.WPF4.ViewModel <br /> { <br /> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">class</span> ViewModelLocator <br /> { <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Initializes a new instance of the ViewModelLocator class.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> <span style="color:#0000ff;">public</span> ViewModelLocator() <br /> { <br /> <span style="color:#008000;">////if (ViewModelBase.IsInDesignModeStatic)</span> <br /> <span style="color:#008000;">////{</span> <br /> <span style="color:#008000;">//// // Create design time view models</span> <br /> <span style="color:#008000;">////}</span> <br /> <span style="color:#008000;">////else</span> <br /> <span style="color:#008000;">////{</span> <br /> <span style="color:#008000;">//// // Create run time view models</span> <br /> <span style="color:#008000;">////}</span> <br /> } <br /> <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Cleans up all the resources.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">static</span> <span style="color:#0000ff;">void</span> Cleanup() <br /> { <br /> <span style="color:#008000;">// Call ClearViewModelName() for each ViewModel.</span> <br /> } <br /> } <br /> } </div> <p> </p> <p>在Cleanup方法下面添加MainViewModel加载方法，这里要用到我们安装的代码片段，在类的空白处输入mvvm，在弹出的代码提示中选择mvvmlocatorproperty，如下：</p> <p></p> <img title="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" border="0" alt="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" src="https://simg.open-open.com/show/e362346d2c9db1a07ae21d4cac70bc05.jpg" width="286" height="265" /> <p> </p> <p>然后按2次tab键，会自动MainViewModel加载方法，代码片段要设置的地方有3个，他们以黄色背景高亮显示，其他相关联地方会自动保持与这3个地方一致，生成的方法如下：</p> <div> #region MainViewModel <br /> <span style="color:#0000ff;">private</span> <span style="color:#0000ff;">static</span> MainViewModel _main; <br /> <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Gets the Main property.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">static</span> MainViewModel MainStatic <br /> { <br /> <span style="color:#0000ff;">get</span> <br /> { <br /> <span style="color:#0000ff;">if</span> (_main == <span style="color:#0000ff;">null</span>) <br /> { <br /> CreateMain(); <br /> } <br /> <br /> <span style="color:#0000ff;">return</span> _main; <br /> } <br /> } <br /> <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Gets the Main property.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> [System.Diagnostics.CodeAnalysis.SuppressMessage( <span style="color:#ff00ff;">"Microsoft.Performance"</span>, <br /> <span style="color:#ff00ff;">"CA1822:MarkMembersAsStatic"</span>, <br /> Justification = <span style="color:#ff00ff;">"This non-static member is needed for data binding purposes."</span>)] <br /> <span style="color:#0000ff;">public</span> MainViewModel Main <br /> { <br /> <span style="color:#0000ff;">get</span> <br /> { <br /> <span style="color:#0000ff;">return</span> MainStatic; <br /> } <br /> } <br /> <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Provides a deterministic way to delete the Main property.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">static</span> <span style="color:#0000ff;">void</span> ClearMain() <br /> { <br /> _main.Cleanup(); <br /> _main = <span style="color:#0000ff;">null</span>; <br /> } <br /> <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Provides a deterministic way to create the Main property.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">static</span> <span style="color:#0000ff;">void</span> CreateMain() <br /> { <br /> <span style="color:#0000ff;">if</span> (_main == <span style="color:#0000ff;">null</span>) <br /> { <br /> _main = <span style="color:#0000ff;">new</span> MainViewModel(); <br /> } <br /> } <br /> <br /> #endregion </div> <p> </p> <p>7、打开App.Xaml，先添加ViewModel命名控件引用，然后为ViewModelLocator添加一个全局的资源，app.xaml的内容如下：</p> <div> < <span style="color:#808000;">Application x:Class=</span> <span style="color:#ff00ff;">"MvvmlightDataBinding.WPF4.App"</span> <span style="color:#808000;"><br /> xmlns=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/winfx/2006/xaml/presentation"</span> <span style="color:#808000;"><br /> xmlns:x=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/winfx/2006/xaml"</span> <span style="color:#808000;"><br /> xmlns:vm=</span> <span style="color:#ff00ff;">"clr-namespace:MvvmlightDataBinding.WPF4.ViewModel"</span> <span style="color:#808000;"><br /> xmlns:d=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/expression/blend/2008"</span> <span style="color:#808000;"><br /> xmlns:mc=</span> <span style="color:#ff00ff;">"http://schemas.openxmlformats.org/markup-compatibility/2006"</span> <span style="color:#808000;"><br /> mc:Ignorable=</span> <span style="color:#ff00ff;">"d"</span> <span style="color:#808000;"><br /> StartupUri=</span> <span style="color:#ff00ff;">"MainWindow.xaml"</span>> <br /> < <span style="color:#808000;">Application.Resources</span>> <br /> <span style="color:#008000;"><!--全局 View Model 加载器--></span> <br /> < <span style="color:#808000;">vm:ViewModelLocator x:Key=</span> <span style="color:#ff00ff;">"Locator"</span> <span style="color:#808000;"><br /> d:IsDataSource=</span> <span style="color:#ff00ff;">"True"</span> <span style="color:#808000;"> /</span>> <br /> < <span style="color:#808000;">/Application.Resources</span>> <br /> < <span style="color:#808000;">/Application</span>> </div> <p> </p> <p>8、打开MainWindow.xaml文件，首先为MainWindow设置DataContext为MainViewModel，当然也可以为Grid设置DataContext，只要我们使用的时候，他在视觉树中可见的范围内，MainWindow.xaml代码如下:</p> <div> < <span style="color:#808000;">Window x:Class=</span> <span style="color:#ff00ff;">"MvvmlightDataBinding.WPF4.MainWindow"</span> <span style="color:#808000;"><br /> xmlns=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/winfx/2006/xaml/presentation"</span> <span style="color:#808000;"><br /> xmlns:x=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/winfx/2006/xaml"</span> <span style="color:#808000;"><br /> <span style="color:#0000ff;">Title</span>=</span> <span style="color:#ff00ff;">"MainWindow"</span> <span style="color:#808000;"> Height=</span> <span style="color:#ff00ff;">"250"</span> <span style="color:#808000;"> Width=</span> <span style="color:#ff00ff;">"300"</span> <span style="color:#808000;"><br /> DataContext=</span> <span style="color:#ff00ff;">"{Binding Main,Source={StaticResource Locator}}"</span>> <br /> < <span style="color:#808000;">Grid</span>> <br /> < <span style="color:#808000;">TextBlock FontSize=</span> <span style="color:#ff00ff;">"16"</span> <span style="color:#808000;"> Text=</span> <span style="color:#ff00ff;">"{Binding WelcomText}"</span> <span style="color:#808000;">/</span>> <br /> < <span style="color:#808000;">/Grid</span>> <br /> < <span style="color:#808000;">/Window</span>> </div> <p> </p> <p>我在窗体中放了一个TextBlock，TextBlock的Text属性绑定到WelcomText，这个WelcomText应该是 DataContext对象的WelcomText属性，这里TextBlock从视觉树最顶层也就是Window继承DataContext绑定，因此这里绑定的WelcomText也就是MainViewModel的WelcomText属性，因此我们需要在MainViewModel中添加 WelcomText属性，修改MainViewModel代码如下：</p> <div> <span style="color:#0000ff;">public</span> <span style="color:#0000ff;">string</span> WelcomText <br /> { <br /> <span style="color:#0000ff;">get</span>; <br /> <span style="color:#0000ff;">set</span>; <br /> } <br /> <span style="color:#008000;">/// <summary></span> <br /> <span style="color:#008000;">/// Initializes a new instance of the MainViewModel class.</span> <br /> <span style="color:#008000;">/// </summary></span> <br /> <span style="color:#0000ff;">public</span> MainViewModel() <br /> { <br /> <span style="color:#0000ff;">if</span> (IsInDesignMode) <br /> { <br /> <span style="color:#008000;">// Code runs in Blend --> create design time data.</span> <br /> WelcomText = <span style="color:#ff00ff;">"设计时的值"</span>; <br /> } <br /> <span style="color:#0000ff;">else</span> <br /> { <br /> <span style="color:#008000;">// Code runs "for real": Connect to service, etc...</span> <br /> WelcomText = <span style="color:#ff00ff;">"运行时的值"</span>; <br /> } <br /> } </div> <p> </p> <p>注意这里IsInDesignMode是判断当前环境是否是设计模式，这在界面和逻辑分离时非常实用，比如当业务逻辑开发未完成时，界面设计人员也可以进行设计，这时只需在IsInDesignMode为True时创造一些测试数据就可以了，同时也实现了所见即所得的界面设计模式;示例中我们在设计时和运行时窗体显示不同的值：</p> <p>设计时截图如下：</p> <p></p> <p></p> <img title="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" border="0" alt="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" src="https://simg.open-open.com/show/90f86862e8ceb850f5860777e3d2e651.jpg" width="304" height="249" /> <p></p> <p>运行时截图如下：</p> <p></p> <img title="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" border="0" alt="Mvvm Light Toolkit for WPF/Silverlight系列之搭建mvvmlight开发框架" src="https://simg.open-open.com/show/12f86d5a2f2442889423361de7c66231.jpg" width="300" height="250" /> <p> </p> <p>OK，到这里我们已经完成搭建Mvvmlight框架了，接着我们继续看不使用ViewModelLocator来搭建Mvvm环境：</p> <p>1~5步与前面搭建标准MvvmLight框架一样。</p> <p>6、这里我们不创建ViewModelLocator，直接打开app.xaml.cs，添加如下代码：</p> <div> <span style="color:#0000ff;">protected</span> <span style="color:#0000ff;">override</span> <span style="color:#0000ff;">void</span> OnStartup(StartupEventArgs e) <br /> { <br /> <span style="color:#0000ff;">base</span>.OnStartup(e); <br /> <br /> MainWindow = <span style="color:#0000ff;">new</span> MainWindow(); <br /> MainWindow.Show(); <br /> MainWindow.DataContext = <span style="color:#0000ff;">new</span> ViewModel.MainViewModel(); <br /> } </div> <p> </p> <p>在App.xaml中去掉StarupUri属性设置。</p> <p>7、修改MainWindow.xaml，完整代码如下：</p> <div> < <span style="color:#808000;">Window x:Class=</span> <span style="color:#ff00ff;">"NormalMVVM.WPF4.MainWindow"</span> <span style="color:#808000;"><br /> xmlns=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/winfx/2006/xaml/presentation"</span> <span style="color:#808000;"><br /> xmlns:x=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/winfx/2006/xaml"</span> <span style="color:#808000;"><br /> <span style="color:#0000ff;">Title</span>=</span> <span style="color:#ff00ff;">"MainWindow"</span> <span style="color:#808000;"> Height=</span> <span style="color:#ff00ff;">"350"</span> <span style="color:#808000;"> Width=</span> <span style="color:#ff00ff;">"525"</span> <span style="color:#808000;"><br /> xmlns:vm=</span> <span style="color:#ff00ff;">"clr-namespace:NormalMVVM.WPF4.ViewModel"</span> <span style="color:#808000;"><br /> xmlns:d=</span> <span style="color:#ff00ff;">"http://schemas.microsoft.com/expression/blend/2008"</span> <span style="color:#808000;"><br /> xmlns:mc=</span> <span style="color:#ff00ff;">"http://schemas.openxmlformats.org/markup-compatibility/2006"</span> <span style="color:#808000;"><br /> mc:Ignorable=</span> <span style="color:#ff00ff;">"d"</span> <span style="color:#808000;"><br /> d:DataContext=</span> <span style="color:#ff00ff;">"{d:DesignInstance Type=vm:MainViewModel, IsDesignTimeCreatable=True}"</span>> <br /> < <span style="color:#808000;">Grid</span>> <br /> < <span style="color:#808000;">TextBlock HorizontalAlignment=</span> <span style="color:#ff00ff;">"Center"</span> <span style="color:#808000;"> VerticalAlignment=</span> <span style="color:#ff00ff;">"Center"</span> <span style="color:#808000;"> FontSize=</span> <span style="color:#ff00ff;">"36"</span> <span style="color:#808000;"> Text=</span> <span style="color:#ff00ff;">"{Binding WelcomText}"</span> <span style="color:#808000;">/</span>> <br /> < <span style="color:#808000;">/Grid</span>> <br /> < <span style="color:#808000;">/Window</span>> </div> <p>注意这里没有使用全局的ViewModelLocator，要在设计时显示ViewModel的内容，需要使用d:DataContext创建一个设计时的实例，这个实例只有在设计时有效，在运行时MainWindow仍然使用app.xaml.cs中动态创建的ViewModel</p> <p>OK，运行示例，得到与前面示例相同的结果。</p> <p>综合看这两种方法，第一个是将ViewModel定义为静态的全局变量，第二个是动态创建，这里不谈孰优孰劣，我觉得应该灵活运用，一个项目往往包含很多个View和ViewModel，全部都定义为静态并不合适，因此我一般都是两种方法混合使用</p> <p>至此，我们应该已经知道搭建和使用mvvmlight框架了，下一章节将介绍mvvm下的数据绑定，以下是本章节的源代码下载：</p> <p>http://download.csdn.net/source/3246642</p> <p>本文来自段子林的博客，原文地址:http://blog.csdn.net/duanzilin/archive/2011/05/03/6388593.aspx</p>