我正在使用文章Model View View-Model (MVVM) in Silverlight作为在Silverlight中创建我自己的MVVM示例的基础 .
我有以下所有部分:
-
main page (加载所有内容)
-
View (带绑定的XAML文件)
-
Model (生成虚假List集合的Customer类)
-
ModelView (继承INotifyPropertyChanged并具有ViewC需要的两个字段的PropertyChanged)
在我的主页我:
-
创建 ViewModel
-
将 ViewModel 绑定到 View 的 DataContext
-
创建 Model (客户)
But now how do I connect the ModelView to the Model? 我觉得我需要以某种方式将我的客户模型注入CustomerViewModel,是吗?但到底怎么样?完成此MVVM示例的下一步是什么,以便我可以开始使用MVVM模式的优点,例如使用测试模型交换模型,使用新视图交换视图等 .
MainPage.xaml.cs: 创建ViewModel,将View附加到ViewModel
using System.Windows.Controls;
using System.Collections.Generic;
namespace TestMvvm345
{
public partial class MainPage : UserControl
{
private CustomerViewModel customerData;
public MainPage()
{
InitializeComponent();
customerData = new CustomerViewModel();
customerHeaderView.DataContext = customerData;
List<Customer> customers = Customer.GetCustomers();
}
}
}
MainPage.xaml: 在主页面的上下文中显示视图
<UserControl x:Class="TestMvvm345.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:TestMvvm345"
Width="400" Height="300">
<Grid x:Name="LayoutRoot" Background="White">
<StackPanel HorizontalAlignment="Left">
<local:CustomerHeaderView x:Name="customerHeaderView" Margin="10"/>
</StackPanel>
</Grid>
</UserControl>
CustomerViewModel.xaml: ViewModel
using System.ComponentModel;
namespace TestMvvm345
{
public class CustomerViewModel : INotifyPropertyChanged
{
private string firstName;
private string lastName;
public string FirstName
{
get { return firstName; }
set
{
firstName = value;
RaisePropertyChanged("FirstName");
}
}
public string LastName
{
get { return lastName; }
set
{
lastName = value;
RaisePropertyChanged("LastName");
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void RaisePropertyChanged(string property)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
}
}
CustomerHeaderView.xaml 查看
<UserControl x:Class="TestMvvm345.CustomerHeaderView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Width="400" Height="300">
<Grid x:Name="LayoutRoot" Background="White">
<StackPanel HorizontalAlignment="Left">
<ListBox x:Name="CustomerList" ItemsSource="{Binding}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock
Text="{FirstName}"/>
<TextBlock
Text="{LastName}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</Grid>
</UserControl>
Customers.cs 模特
using System;
using System.Collections.Generic;
namespace TestMvvm345
{
public class Customer
{
public int ID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int NumberOfContracts { get; set; }
public static List<Customer> GetCustomers()
{
List<Customer> customers = new List<Customer>();
customers = new List<Customer>();
customers.Add(new Customer { FirstName = "Jim", LastName = "Smith", NumberOfContracts = 23 });
customers.Add(new Customer { FirstName = "Jane", LastName = "Smith", NumberOfContracts = 22 });
customers.Add(new Customer { FirstName = "John", LastName = "Tester", NumberOfContracts = 33 });
customers.Add(new Customer { FirstName = "Robert", LastName = "Smith", NumberOfContracts = 2 });
customers.Add(new Customer { FirstName = "Hank", LastName = "Jobs", NumberOfContracts = 5 });
return customers;
}
}
}
1 回答
我使用ViewModel的方式有些不同 . 在我的例子中,它实际上包装了Model类,将大部分数据传递给模型 . 这样,模型中的所有标准业务规则仍然可以按照它们应该的方式运行 . ViewModel仅公开数据绑定或其他UI目的实际需要的属性 . 此外,ViewModel可能包含用于数据绑定的其他属性/方法 .
因此,使用您的客户示例:namespace TestMvvm345 {public class CustomerViewModel:INotifyPropertyChanged {
}
现在,在您的UI中,使用以下代码进行绑定:customerHeaderView.DataContext = CustomerViewModel.GetCustomers();
ViewModel中的代码确实变得有点大,但很多可以放在基类中,并且所有转到模型的属性都完全相同(想想T4模板) .