Wpf实例-MVVM模式实现的登录窗体

参考资料 kingmoon [MVVM专题] 又见经典入门实例

1. 程序截图

2.程序的结构图

3.说明：
如图2所示，Model中存放的是User类文件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace WpfApp.Model
{
public class User
    {
public string UserName { get; set; }
public int UserId { get; set; }
public string Password { get; set; }
    }
}

ViewModel

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Windows.Input;
using WpfApp.Model;
using WpfApp.Command;
using System.Windows;


namespace WpfApp.ViewModel
{
public class UserViewModel : INotifyPropertyChanged
    {
#region 私有字段
private string userName;

private string userPassword;

private ICommand loginCommand;

private User user = new User(); 
#endregion
#region 属性
public ICommand LoginCommand
        {
get { return loginCommand; }
        }
public string UserName
        {
get
            {
return userName;
            }
set
            {
this.userName = value;
if (this.PropertyChanged != null)
                {
this.PropertyChanged(this, new PropertyChangedEventArgs("UserName"));
                }
            }
        }

public string UserPassword
        {
get
            {
return userPassword;
            }
set
            {
this.userPassword = value;
if (this.PropertyChanged != null)
                {
this.PropertyChanged(this, new PropertyChangedEventArgs("UserPassword"));
                }
            }
        } 
#endregion

public UserViewModel()
        {
            user.UserId = 1;
            user.UserName = "huangxi";
            user.Password = "123";
            loginCommand = new LoginCommand(this);
        }

#region 公共方法
public void QueryData()
        {
if (!string.IsNullOrEmpty(this.UserName))
            {
if (this.UserName != user.UserName)
                {
return;
                }
if (this.UserPassword != user.Password)
                {
return;
                }
                MessageBox.Show("登录成功");
            }
        } 
#endregion
#region INotifyPropertyChanged成员
public event PropertyChangedEventHandler PropertyChanged;
#endregion
    }
}

还有Command，存放的是Command,实现了ICommand接口

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;
using WpfApp.ViewModel;

namespace WpfApp.Command
{
public class LoginCommand:ICommand
    {
private UserViewModel userViewModel;
#region ICommand成员
public bool CanExecute(object parameter)
        {
return true;
        }

public event EventHandler CanExecuteChanged;

public void Execute(object parameter)
        {
            userViewModel.QueryData();
        } 
#endregion

public LoginCommand(UserViewModel userViewModel)
        {
this.userViewModel = userViewModel;
        }
    }
}

最后是View层，

<Window x:Class="WpfApp.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Label Content="用户名" HorizontalAlignment="Left" Margin="73,80,0,0" VerticalAlignment="Top"/>
<Label Content="密码" HorizontalAlignment="Left" Margin="73,138,0,0" VerticalAlignment="Top" RenderTransformOrigin="0.798,-0.492"/>
<Button Content="BtnLogin" HorizontalAlignment="Left" Margin="229,221,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click"/>
<TextBox x:Name ="txtUserName" HorizontalAlignment="Left" Height="23" Margin="203,80,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120" Text="{Binding UserName,Mode=TwoWay}"/>

<TextBox x:Name="txtPassword" HorizontalAlignment="Left" Height="23" Margin="203,141,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120" Text="{Binding UserPassword,Mode=TwoWay}"/>

</Grid>
</Window>

这里有一个问题，因为默认的Password没法绑定，这里采用的TextBox代替，网络上有很多Password的帮助类，有兴趣的同学可以自行百度。

界面层的后台代码

using System.Windows;
using WpfApp.ViewModel;

namespace WpfApp
{
/// <summary>
/// MainWindow.xaml 的交互逻辑
/// </summary>
public partial class MainWindow : Window
    {
private UserViewModel userViewModel = null;
public MainWindow()
        {
            InitializeComponent();
            userViewModel = new UserViewModel();
this.DataContext = userViewModel;
        }

private void Button_Click(object sender, RoutedEventArgs e)
        {

if (this.userViewModel != null)
            {
this.userViewModel.UserName = this.txtUserName.Text;
this.userViewModel.UserPassword = this.txtPassword.Text;
this.userViewModel.LoginCommand.Execute(null);
            }
        }
    }
}

到这里就结束了。