entityMap|blocks|key|8u9b7|text|我们使用此模式的一个变体，这里我们有代表虚拟机的控制器，因此视图的数据上下文是虚拟机，而我们的DTO是虚拟机/控制器的属性。我们仍然称它为控制器，因为我们将它用作控制点，从而处理来自视图的某些命令。这就是(我认为)我们将实现像您这样的命令的地方。|type|unstyled|depth|inlineStyleRanges|entityRanges|data^0^^$0|$]|1|@$2|3|4|5|6|7|8|C|9|@]|A|@]|B|$]]]]

We use a variant on this pattern, Here we have controllers that represent the VM, so the datacontext of the View is the VM and our DTOs are properties of the VM/Controller. We call it a controller still as we use this as the control point and thus handle certain command from the View. This is (I think) where we would implement the command such as yours.

entityMap|blocks|key|anf7o|text|视图永远不应该实例化在UI层“下面”的任何地方。VM位于该领域的下方，因此这里不是放置该逻辑的地方(正如您已经意识到的那样)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3gti|几乎总是会有一些UI级事件指示需要创建视图。在您的示例中，它可能是数据网格上的行(双击)单击事件。这将是一个新的地方，并显示您的DetailsView窗口。^0|0^^$0|$]|1|@$2|3|4|5|6|7|8|E|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|F|9|@]|A|@]|B|$]]]]

Views should never be instantiated anywhere "below" the UI layer. VMs exist below that realm, therefore this is not the place to put that logic (as you've already realized).

There will almost always be some UI level event that will indicate the need to create the view. In your example, it might be a row (double) click event on the datagrid. That would be the place to new-up and show your DetailsView window.

entityMap|0|type|IMAGE|mutability|IMMUTABLE|data|imageUrl|https://ask.qcloudimg.com/http-save/actteam/dc2a7ed683ebaeff12e504c84f176c62.ashx|imageAlt|blocks|key|alg7g|text|正如基夫所说：|unstyled|depth|inlineStyleRanges|entityRanges|vl9|视图永远不应该实例化在UI层“下面”的任何地方。VM位于该领域的下方，因此这里不是放置该逻辑的地方(正如您已经意识到的那样)。|ac7bj|几乎总是会有一些UI级事件指示需要创建视图。在您的示例中，它可能是数据网格上的行(双击)单击事件。这将是一个新的地方，并显示您的DetailsView窗口。|j7h0|62re6|您必须认识到，M-V-VM与MVC或MVP等其他模式略有不同。ViewModel不直接了解UI。打开另一个视图是特定于视图的功能。视图模型不应该关心什么或者有多少视图在使用它的数据。我很可能永远不会通过命令打开视图。|7mggm|​|c6v4j|?|atomic|offset|length|53dot^0|0|0|0|0|0|0|0|1|0|0^^$0|$1|$2|3|4|5|6|$7|8|9|-4]]]|A|@$B|C|D|E|2|F|G|Y|H|@]|I|@]|6|$]]|$B|J|D|K|2|F|G|Z|H|@]|I|@]|6|$]]|$B|L|D|M|2|F|G|10|H|@]|I|@]|6|$]]|$B|N|D|-4|2|F|G|11|H|@]|I|@]|6|$]]|$B|O|D|P|2|F|G|12|H|@]|I|@]|6|$]]|$B|Q|D|R|2|F|G|13|H|@]|I|@]|6|$]]|$B|S|D|T|2|U|G|14|H|@]|I|@$V|15|W|16|B|17]]|6|$]]|$B|X|D|R|2|F|G|18|H|@]|I|@]|6|$]]]]

As Kiff noted:
<blockquote>
Views should never be instantiated anywhere &quot;below&quot; the UI layer. VMs exist below that realm, therefore this is not the place to put that logic (as you've already realized).
There will almost always be some UI
level event that will indicate the
need to create the view. In your
example, it might be a row (double)
click event on the datagrid. That
would be the place to new-up and show
your DetailsView window.
</blockquote>
You have to realize that M-V-VM is slightly different than other patterns like MVC or MVP. The ViewModel has no direct knowledge of the UI. Opening another view is a view-specific function. The View Model should care less what or how many views are using it's data. I most likely would never open the view via a command.
<a href="https://web.archive.org/web/20060624141450/http://blogs.msdn.com:80/johngossman/attachment/576163.ashx" rel="nofollow noreferrer"><img src="https://web.archive.org/web/20060624141450/http://blogs.msdn.com:80/johngossman/attachment/576163.ashx" alt="alt text" /></a>

entityMap|blocks|key|bpkkk|text|这是一个基本的经验法则。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|etlhg|如果您在视图中处理本地操作，则可以从视图模型初始化。|unordered-list-item|ap5he|如果它是交叉视图(比如显示搜索屏幕)，那么要么使用EventAggregator模式(一个事件服务)，要么注入一个应用程序控制器，在该应用程序控制器上调用方法，然后显示搜索结果。^0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|H|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|I|9|@]|A|@]|B|$]]|$2|F|4|G|6|E|8|J|9|@]|A|@]|B|$]]]]

Here's a basic rule of thumb on this.

<ul>
<li>If you are handling local actions in
your view, you can intiate from the
view model. </li>
<li>If it's cross view (like showing a search screen), then either use an EventAggregator pattern (an eventing service) or inject an Application Controller which you invoke methods on, and it in turn displays the search.</li>
</ul>

entityMap|0|type|LINK|mutability|MUTABLE|data|url|http://catel.codeplex.com/|blocks|key|6ip6p|text|Catel包括一种方法，该方法涉及使用IUIVisualizerService..。该接口定义了一个UI控制器，可用于在ViewModel中以模式或非模式形式显示对话框。基本上，在父vm中，您创建了应该留在新视图后面的视图模型，服务找到关联的视图模型(基于某些约定或注册)，然后显示它。|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges^0|J|K|0|5|0^^$0|$1|$2|3|4|5|6|$7|8]]]|9|@$A|B|C|D|2|E|F|M|G|@$H|N|I|O|J|K]]|L|@$H|P|I|Q|A|R]]|6|$]]]]

<a href="http://catel.codeplex.com/" rel="nofollow">Catel</a> includes an approach which involves the use of <code>IUIVisualizerService</code>. This interface defines a UI controller which can be used to display dialogs in either modal or modaless form from a ViewModel. Basically, inside the parent vm, you create the viewmodel that should stay behind the new view, and the service finds the associated one (based on some convention or registration) and then shows it.

I've just started looking into M-V-VM for a WPF application. Everything makes sense so far besides this particular issue...

I have a ViewModel I'll call Search. This ViewModel binds to a datagrid and lists results of items. Now, I have a command that needs to bring up another view, the item's details.

Putting the logic to show another view in the Search View doesn't seem right, it's not testable at all.

Here is my ViewModel implementation, which is not testable...

<pre><code>public class SearchViewModel
{
 public void SelectItem()
 {
 // I want to call the DetailsView from here
 // this seems wrong, and is untestable
 var detailsView = new DetailsView();
 detailsView.Show();
 }
}
</code></pre>

Where does the logic to show a view from a ViewModel method go in this pattern?

M-V-VM Design Question. Calling View from ViewModel

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

 我刚刚开始研究WPF应用程序的M-V-VM。到目前为止，除了这个特殊的问题之外，所有的事情都是有意义的。 我有一个ViewModel，我把它叫做Search。此ViewModel绑定到数据网格并列出项目的结果。现在，我有一个命令需要调出另一种观点，项目的详细信息。 在搜索视图中显示另一个视图的逻辑似乎是不正确的，它根...

问M-V-VM设计问题。从ViewModel调用视图
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问M-V-VM设计问题。从ViewModel调用视图EN