Converting from normal list data to a database in wpf xaml

问题

So I have been trying to fix many errors in my system for a while and I'm pretty close to being done. One of these errors resulted in me creating a simple list that is the equivalent of my database fields. As we all know, this is is stupid for a lot of data - and now I've finished with test data, it's time to implement a database connection.

So below are the code files that I am using and descriptions with them:

DBDisplayViewModel.cs

public class DBDisplayViewModel
{
    public ICollectionView Users { get; private set; }

    /// <summary>
    /// To pull the database
    /// </summary>
    private static string connectionString = Properties.Settings.Default.DBUsers;
    public DBDisplayViewModel()
    {
        //TODO Database connection

         #Region old code
     var _users = new List<User>
                             {
                                 new User
                                     {
                                         ID = "IDTest",
                                         FirstName = "FNTest",
                                         LastName = "LNTest",
                                     },
        #endregion


        Users = CollectionViewSource.GetDefaultView(_users);
    }

}

Users.cs

    public class Patients : INotifyPropertyChanged
{
    private string _id;
    private string _firstName;
    private string _lastName;

    /// <summary>
    /// Define ID
    /// </summary>
    public string ID
    {
        get { return _id; }
        set
        {
            _id = value;
            NotifyPropertyChanged("ID");
        }
    }

    /// <summary>
    /// Define First Name
    /// </summary>
    public string FirstName
    {
        get { return _firstName; }
        set
        {
            _firstName = value;
            NotifyPropertyChanged("FirstName");
        }
    }

    /// <summary>
    /// Define Last Name
    /// </summary>
    public string LastName
    {
        get { return _lastName; }
        set
        {
            _lastName = value;
            NotifyPropertyChanged("LastName");
        }
    }



    /// <summary>
    /// INotifyPropertyChanged Members
    /// </summary>
    public event PropertyChangedEventHandler PropertyChanged;


    /// <summary>
    /// Private Helpers
    /// </summary>
    /// <param name="propertyName"></param>
    private void NotifyPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

}

DBDisplay.xaml simply has a binding (that needs to connect to the DB)

<DataGrid ItemsSource="{Binding Users}"

DBDisplay.xaml.cs simply has the ViewModel in

 public DBDisplay()
    {
        InitializeComponent();
        // Pull in the ViewModel
        DataContext = new DBDisplayViewModel();
    }

So from what I can see, in the View Model, where the #Region is, I need to connect to my (preexisting) database, DBUsers

Can someone break down the way to do this, and if I'm doing anything wrong? Thank you ever so much

回答1:

If I understand you correctly, the EntityFramework should help you work with the DB. You need to install the NuGet using the EntityFramework. (More info: https://msdn.microsoft.com/en-us/data/jj574514.aspx , http://metanit.com/sharp/entityframework/3.3.php)

app.config

 <configSections>
    <entityFramework>
       <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
      <providers>
          <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
      </providers>
    </entityFramework>
    <connectionStrings>
         <add name="DictionaryPlus" connectionString="Data Source=(localdb)\v11.0;Initial Catalog=DataBaseName;"
    providerName="System.Data.SqlClient"/>
    </connectionStrings>
 </configuration>

xaml.cs file

public partial class MainWindow : Window
{
    Db_Context db = null;

    public MainWindow()
    { db = new Db_Context(); }

    private async void Window_Loaded(object sender, RoutedEventArgs e)
    {

        await db.Users.LoadAsync();

        /* Data usage */

        /* Binding */

        CollectionViewSource userViewSource = ((CollectionViewSource)(this.FindResource("userViewSource")));
        userViewSource.Source = db.Users.Local;

        /* Add data */

        db.Users.Add(new User());
        await db.SaveChangesAsync();

        this.list_Users.Items.Refresh();

    } 
}

public class Db_Context : DbContext
{
    public Db_Context() : base("DataBaseName") { }
    public DbSet<User> Users { get; set; }
}

xaml file

 <Window.Resources>
      <CollectionViewSource x:Key="userViewSource" d:DesignSource="{d:DesignInstance {x:Type Model:User}, CreateList=True}"/>
 </Window.Resources>

 <ListBox x:Name="list_Users" DisplayMemberPath="Name" ItemsSource="{Binding Source={StaticResource userViewSource}}" SelectedValuePath="Id" Focusable="False"/>

来源：https://stackoverflow.com/questions/33924821/converting-from-normal-list-data-to-a-database-in-wpf-xaml