EF dbcontext在dynamo自定义节点中返回空的dbset
EF dbcontext在dynamo自定义节点中返回空的dbset
提问于 2021-03-22 22:28:49
我想在Dynamo节点中创建一个下拉列表，以选择一个项目并返回属性。
我有一个解决方案，其中我有3个项目。一个项目是连接到数据库的连接器，该数据库由其他两个项目中的任何一个使用。
另外两个项目本质上是UI，用于显示从数据库获取的项。一个是WPF应用程序，另一个是Dynamo节点。
当我使用WPF应用程序时，来自连接器dbcontext的数据返回带有值的dbset。但是当我将连接器与Dynamo节点一起使用时，连接器返回一个空的dbset。因此，节点中的组合框是空的。
连接器dbcontext
using Autodesk.DesignScript.Runtime;
using System.Data.Entity;
namespace ConnectToDB
{
[IsVisibleInDynamoLibrary(false)]
public partial class ShapesModelContext : DbContext
{
[IsVisibleInDynamoLibrary(false)]
public ShapesModelContext()
: base("ShapesModelContext")
{
}
public DbSet<C> C { get; set; }
public DbSet<C_m> C_m { get; set; }
public DbSet<HP> HPs { get; set; }
public DbSet<HP_m> HP_m { get; set; }
public DbSet<HSS> HSSes { get; set; }
public DbSet<HSS_m> HSS_m { get; set; }
public DbSet<L> L { get; set; }
public DbSet<L_m> L_m { get; set; }
public DbSet<M> M { get; set; }
public DbSet<M_m> M_m { get; set; }
public DbSet<MC> MCs { get; set; }
public DbSet<MC_m> MC_m { get; set; }
public DbSet<MT> MTs { get; set; }
public DbSet<MT_m> MT_m { get; set; }
public DbSet<PIPE> PIPEs { get; set; }
public DbSet<PIPE_m> PIPE_m { get; set; }
public DbSet<S> S { get; set; }
public DbSet<S_m> S_m { get; set; }
public DbSet<ShapesID> ShapesIDs { get; set; }
public DbSet<ST> STs { get; set; }
public DbSet<ST_m> ST_m { get; set; }
public DbSet<sysdiagram> sysdiagrams { get; set; }
public DbSet<TwoL> TwoLs { get; set; }
public DbSet<TwoL_m> TwoL_m { get; set; }
public DbSet<W> W { get; set; }
public DbSet<W_m> W_m { get; set; }
public DbSet<WT> WTs { get; set; }
public DbSet<WT_m> WT_m { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.C)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.HP)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.HSS)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.L)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.M)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.MC)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.MT)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.PIPE)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.S)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.ST)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.TwoL)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.W)
.WithRequired(e => e.ShapesID);
modelBuilder.Entity<ShapesID>()
.HasOptional(e => e.WT)
.WithRequired(e => e.ShapesID);
}
}
}视图模型和获取数据的方法。
using System.Collections.Generic;
using Newtonsoft.Json;
namespace ConnectToDB
{
public class AISC_ShapesViewModel
{
private List<string> _Shapes;
public List<string> Shapes
{
get
{
return _Shapes;
}
set
{
_Shapes = value;
}
}
public List<string> LoadSections()
{
List<string> thaColl = new List<string>();
using (var context = new ShapesModelContext())
{
var sections = context.ShapesIDs;
foreach (var section in context.ShapesIDs)
{
thaColl.Add(section.EDI_Std_Nomenclature);
}
}
return Shapes = thaColl;
}
}
}在组合框中正确显示数据的WPF应用程序。
<Window x:Class="WPFUI.MainWindow"
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:WPFUI"
xmlns:vm="clr-namespace:ConnectToDB;assembly=ConnectToDB"
Loaded="Main_Loaded"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<vm:AISC_ShapesViewModel x:Key="thaMidClass"/>
</Window.Resources>
<Grid DataContext="{Binding Mode=OneWay, Source={StaticResource thaMidClass}}">
<ComboBox x:Name="comboBox" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top" Width="120" ItemsSource="{Binding Shapes}"/>
<Label x:Name="section" Content="{Binding SelectedItem, ElementName=comboBox}" HorizontalAlignment="Left" Margin="173,10,0,0" VerticalAlignment="Top" Width="291" Height="22" FontSize="10"/>
</Grid>
</Window>我的Dynamo节点的用户控件没有显示数据。
<UserControl x:Class="DynamoUI.Dynamo_UI"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:DynamoUI"
xmlns:vm="clr-namespace:ConnectToDB;assembly=ConnectToDB"
Loaded="Comboloaded"
mc:Ignorable="d" Height="73.5" Width="219.5">
<UserControl.Resources>
<vm:AISC_ShapesViewModel x:Key="thaMidClass"/>
</UserControl.Resources>
<Grid DataContext="{StaticResource thaMidClass}">
<ComboBox x:Name="comboBox" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top" Width="193" ItemsSource="{Binding Path=Shapes}"/>
</Grid>
</UserControl>节点模型。
using CoreNodeModels;
using Dynamo.Graph.Nodes;
using Newtonsoft.Json;
namespace DynamoUI
{
[NodeName("AISC Shapes")]
[NodeDescription("Query AISC shapes database")]
[NodeCategory("AISC.Shapes Node")]
//[InPortNames("A")]
//[InPortTypes("List")]
//[InPortDescriptions("List A")]
[OutPortNames("Output")]
[OutPortTypes("Dictionary")]
[OutPortDescriptions("Shape properties dictionary")]
[IsDesignScriptCompatible]
class AISC_Shape_Node_Model: NodeModel
{
[JsonConstructor]
public AISC_Shape_Node_Model()
{
RegisterAllPorts();
}
}
}节点视图。
using Dynamo.Controls;
using Dynamo.Wpf;
namespace DynamoUI
{
class AISC_Shape_Node_View : INodeViewCustomization<AISC_Shape_Node_Model>
{
public void CustomizeView(AISC_Shape_Node_Model model, NodeView nodeView)
{
var ui = new Dynamo_UI();
nodeView.inputGrid.Children.Add(ui);
ui.DataContext = model;
}
public void Dispose()
{
}
}
}连接字符串。
<connectionStrings>
<add name="ShapesModelContext" connectionString="data source=MyDatabase;initial catalog=AISC_Shapes_V15;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework" providerName="System.Data.SqlClient" />
</connectionStrings>使用Dynamo节点。
使用WPF应用程序。
每次我使用WPF前端时，都会调用此方法。
public List<string> LoadSections()
{
List<string> thaColl = new List<string>();
using (var context = new ShapesModelContext())
{
var sections = context.ShapesIDs;
foreach (var section in context.ShapesIDs)
{
thaColl.Add(section.EDI_Std_Nomenclature);
}
}
return Shapes = thaColl;
}而且，在调试步骤中，我们可以看到创建了从EF DbContext继承的“ShapesModelContext”，并将ShapesIDs分配给了各个部分。代码进入for循环并遍历DbSet。
但是当我使用Dynamo作为前端时，同样的代码会被执行，但是在NodeModel循环中，它会检查DbSet并立即退出循环，因为DbSet是空的。
回答 1
Stack Overflow用户
发布于 2021-03-24 02:54:47
问题是Dynamo使用它自己的连接字符串。连接字符串指向：
Data Source=(localdb)\mssqllocaldb初始目录名称由在DbContext中找到的连接字符串名称定义。
Initial Catalog=ShapesModelContext因此，我更改了LoadSections()方法以指定正确的连接字符串。
原始代码是：
public List<string> LoadSections()
{
List<string> thaColl = new List<string>();
using (var context = new ShapesModelContext())
{
var sections = context.ShapesIDs;
foreach (var section in context.ShapesIDs)
{
thaColl.Add(section.EDI_Std_Nomenclature);
}
}
return Shapes = thaColl;
}现在添加了连接字符串。
using (var context = new ShapesModelContext())
{
context.Database.Connection.ConnectionString = "data source=XXXXX;initial catalog=XXXXXXXX;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework";
var sections = context.ShapesIDs;
foreach (var section in sections)
{
thaColl.Add(section.EDI_Std_Nomenclature);
}
}
return Shapes = thaColl; 页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/66748057
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