WPF MVVM-如何在单击按钮时从MainWindowViewModel中显示视图 [英] WPF MVVM - How to Show a view from MainWindowViewModel upon Clicking on button

问题描述

可能重复:
使用WPF在WPF中创建新窗口的最佳方法MVVM

Possible Duplicate:
The best approach to create new window in WPF using MVVM

你好朋友，

我有两个视图 MainWindowView 和 AddCustomerView .我在MainwindowView.xmal中有包含按钮的菜单.

I have two view MainWindowView and AddCustomerView. I have menu containing buttons in MainwindowView.xmal.

如何通过单击按钮从MainWindowViewModel中弹出 AddCustomerView.

How could i popup AddCustomerView from MainWindowViewModel by clicking on button.

我的启动代码App.xmal.cs是..

My App.xmal.cs for Startup code is..

base.OnStartup(e);
MainWindow window = new MainWindow();
var viewModel = new MainWindowViewModel();
window.DataContext = viewModel;
window.Show();

在按钮执行代码中显示AddCustomerView的代码是什么.

What is the code for showing AddCustomerView in buttonexecute code.

 public void AddNewCustomerWindowExecute() //This is button handler
 {
     // How to show AddCustomerView from MainWindowViewModel
 }

推荐答案

在视图中处理

可能是最简单的方法.

Handle it in the view

Probably the most simple approach.

private void AddCustomerView_Click(object sender, RoutedEventArgs e)
{
    AddCustomerView view = new AddCustomerView(data);
    view.Show();
}

ViewModel公开一个事件

这有一个缺点:它需要大量的手动编码.

ViewModel exposes an event

This has one drawback: it requires lots of manual coding.

public class MainWindowViewModel 
{
    public event EventHandler AddCustomerViewShowed;

    public void AddNewCustomerWindowExecute()
    {
        if (AddCustomerViewShowed != null)
            AddCustomerViewShowed(this, EventArgs.Empty);
    }
}

在视图中处理

var viewModel = new MainWindowViewModel();
viewModel.AddCustomerViewShowed += (s, e) => new AddCustomerView(data).Show();

处理所有视图的控制器

public class Controller : IController
{
    public void AddCustomer()
    {
        AddCustomerView view = new AddCustomerView(data);
        view.Show();
    }
}

public class MainWindowViewModel 
{
    IController controler;

    public MainWindowViewModel(IController controller)
    {
        this.controller = controller;
    }

    public void AddNewCustomerWindowExecute()
    {
        controller.AddCustomer();
    }
}

中介者模式

某些MVVM框架(例如 MVVM Light )使用此模式.

Mediator pattern

Some MVVM frameworks (e.g. MVVM Light) use this pattern.

public class App // or in the view or somewhere else
{
    public void RegisterMessenger()
    {
        Messenger.Default.Register<AddCustomerMessage>(this, ProcessAddCustomerMessage);            
    }

    private void ProcessAddCustomerMessage(AddCustomerMessage message)
    {
        AddCustomerView view = new AddCustomerView(data);
        view.Show();
    }
}

public class MainWindowViewModel 
{
    public void AddNewCustomerWindowExecute()
    {
        Messenger.Default.Send(new AddCustomerMessage(...));
    }
}

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