如何从一个视图中切换视图？ [英] How do I switch views from within a view?

问题描述

我在做一个WPF应用程序利用的MVVM光框架。

I'm making a WPF application making use of the MVVM light framework.

我试图做的是在一个视图中登录表单，当用户按下一个按钮，视图中它启动了连接视图模型一个LoginCommand。从那里，我不是要启动它包含应用程序的其余部分，或者简单地切换从同一个窗口视图的新窗口。

What I'm trying to do is have a login form in a view, when the user presses a button within that view it launches a LoginCommand for the attached ViewModel. From there I either want to launch a new window which holds the rest of the application, or simply switch views from the same window.

目前我有它，以便有一个视图叫的MainView有内部势必视图1内容的控制。但是切换到视图2我需要把按钮此有关的MainView，而不是在视图1属于它的地方。

Currently I have it so that there is a view called MainView which has a content control inside bound to View1. However to switch to View2 I need to put the button for this on MainView, and not within View1 where it belongs.

任何意见？

推荐答案

通常我做这一块的两种方式：

Usually I do this one of two ways:

如果登录窗口是一次性启动应用程序之前需要的东西，我就会把它放在应用对象 OnStartup（）方法>

If the login window is a one-time thing required before starting the application, I will put it in the OnStartup() method of the Application object

protected override void OnStartup(StartupEventArgs e)
{
    base.OnStartup(e);

    // Login
    var login = new LoginDialog();
    var loginVm = new LoginViewModel();

    login.DataContext = loginVm;
    login.ShowDialog();

    if (!login.DialogResult.GetValueOrDefault())
    {
        // Error is handled in login class, not here
        Environment.Exit(0);
    }

    // If login is successful, show main application
    var app = new ShellView();
    var appModel = new ShellViewModel();

    app.DataContext = viewModel;
    app.Show();
}

另一种方式，我通常做，这是通过 ShellViewModel 或 ApplicationViewModel 它处理我所有的窗口管理。此方法使用的DataTemplates 来定义每个屏幕，并且采用了 ContentControl中作为当前画面的占位符 ShellView 或 ApplicationView 。

The other way I usually do this is through a ShellViewModel or ApplicationViewModel which handles all my window management. This method uses DataTemplates to define each screen, and uses a ContentControl as a placeholder for the current screen in the ShellView or ApplicationView.

我通常与事件结合本某种一样的系统微软棱镜的 EventAggregator ，所以它可以侦听特定类型的消息，如了OpenWindow 或 CloseWindow 消息。如果你有兴趣，我有一个博客帖子大约的ViewModels 这之间的沟通应该给你一个什么样的事件系统，看起来像一个更好的主意。

I usually combine this with an Event System of some kind, like Microsoft Prism's EventAggregator, so it can listen for messages of a specific type, such as OpenWindow or CloseWindow messages. If you're interested, I have a blog post about Communication between ViewModels that should give you a better idea of what an event system looks like.

例如，我的 ShellViewModel 可以通过显示启动 LoginViewModel （A 的DataTemplate 是用来告诉WPF绘制 LoginViewModel LoginView ），它会订阅接收类型的消息 SuccessfulLogin $ C>。一旦 LoginViewModel 广播 SuccessfulLogin 消息，在 ShellViewModel 将关闭 LoginViewModel 并用 ApplicationViewModel 替换它。你可以看到在我的导航与MVVM这样的一个例子

For example, my ShellViewModel might start by displaying a LoginViewModel (a DataTemplate is used to tell WPF to draw the LoginViewModel with the LoginView), and it would subscribe to receive messages of type SuccessfulLogin. Once the LoginViewModel broadcasts a SuccessfulLogin message, the ShellViewModel will close the LoginViewModel and replace it with the ApplicationViewModel. You can see an example of this in my article on Navigation with MVVM

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