这个问题是参考我在这里的旧问题:datagrid中的主键始终为零
在我之前的问题中,我正在研究具有许多关系的大型数据库,因此我想尝试一下并在此基础(非常基础)的项目上进行测试。
我所做的是我创建了简单的基本wpf应用程序。添加了本地数据库,其中只有一个表有两列。一个是id列,它是主键并自动递增;另一个是简单的varchar。我将其添加为数据源并从该数据源创建了网格。
这是我的xaml:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:WpfApplication4" mc:Ignorable="d" x:Class="WpfApplication4.MainWindow"
Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded_1">
<Window.Resources>
<CollectionViewSource x:Key="tablesViewSource" d:DesignSource="{d:DesignInstance {x:Type local:Table}, CreateList=True}"/>
</Window.Resources>
<Grid DataContext="{StaticResource tablesViewSource}">
<DataGrid x:Name="tablesDataGrid" AutoGenerateColumns="False" EnableRowVirtualization="True" ItemsSource="{Binding}" Margin="47,24,70,95" RowDetailsVisibilityMode="VisibleWhenSelected">
<DataGrid.Columns>
<DataGridTextColumn x:Name="idColumn" Binding="{Binding Id}" Header="Id" Width="SizeToHeader"/>
<DataGridTextColumn x:Name="nameColumn" Binding="{Binding name}" Header="name" Width="SizeToHeader"/>
</DataGrid.Columns>
</DataGrid>
<Button Content="Button" HorizontalAlignment="Left" Margin="221,266,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click_1"/>
</Grid>
仅有的两行代码是我编写的。Rest是自动生成的,现在我想从gridview更新我的数据,但是最大的问题是数据没有更新,它一直加零。
我在这里添加了整个cs文件。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace WpfApplication4
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private System.Data.Objects.ObjectQuery<Table> GetTablesQuery(Database1Entities database1Entities)
{
System.Data.Objects.ObjectQuery<WpfApplication4.Table> tablesQuery = database1Entities.Tables;
// Returns an ObjectQuery.
return tablesQuery;
}
private void Window_Loaded_1(object sender, RoutedEventArgs e)
{
WpfApplication4.Database1Entities database1Entities = new WpfApplication4.Database1Entities();
// Load data into Tables. You can modify this code as needed.
System.Windows.Data.CollectionViewSource tablesViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("tablesViewSource")));
System.Data.Objects.ObjectQuery<WpfApplication4.Table> tablesQuery = this.GetTablesQuery(database1Entities);
tablesViewSource.Source = tablesQuery.Execute(System.Data.Objects.MergeOption.AppendOnly);
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
var context = new WpfApplication4.Database1Entities();
// Database1Entities db = new Database1Entities();
// db.SaveChanges();
context.SaveChanges();
}
}
}`
我已经开始怀疑自己的基本知识。请帮忙。
这对我有用(调整变量名):
using System.Data.Entity;
private Database1Entities _context = new Database1Entities ();
private void Window_Loaded(object sender, RoutedEventArgs e) {
System.Windows.Data.CollectionViewSource tableViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("tableViewSource")));
_context.Table.Load();
tableViewSource.Source = _context.Table.Local;
}
private void Button_Click(object sender, RoutedEventArgs e) {
_context.SaveChanges();
tableDataGrid.Items.Refresh();
}
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