Asp.net 非类型化为强类型数据表

我今天试着做些实验。我有一个使用非类型化数据表作为模型实体的应用程序。 它们都是这样制作的：

Imports System.Data
Imports System.Runtime.Serialization
Imports System.ComponentModel

<DesignerCategory("Code"), system.Serializable()>
Partial Public Class SomeTable1
    Inherits DataTable

#Region
    Public Const TABLE_NAME As String = "SomeTable1"

    Public Const FIELD_SomeField1 As String = "SomeField1"
    Public Const FIELD_SomeField2 As String = "SomeField2"
#End Region

    Protected Sub New(ByVal info As SerializationInfo, ByVal context As StreamingContext)
        MyBase.New(info, context)
    End Sub

    Public Sub New()
        MyBase.New()

        With Columns
            .Add(FIELD_SomeField1, GetType(System.String)).DefaultValue = String.Empty
            .Add(FIELD_SomeField2, GetType(System.Double)).DefaultValue = 0
        End With

        Dim keys(1) As DataColumn
        keys(0) = Columns(FIELD_SomeField1)
        TableName = TABLE_NAME
        PrimaryKey = keys
    End Sub
End Class

导入系统数据
导入System.Runtime.Serialization
导入System.ComponentModel
部分公共类表1
继承数据表
#区域
Public Const TABLE_NAME为String=“SomeTable1”
公共常量字段\u SomeField1为String=“SomeField1”
公共常量字段\u SomeField2为String=“SomeField2”
#末端区域
受保护的子新建（ByVal信息作为SerializationInfo，ByVal上下文作为StreamingContext）
MyBase.New（信息、上下文）
端接头
公共分新（）
MyBase.New（）
带柱
.Add（FIELD_SomeField1，GetType（System.String））.DefaultValue=String.Empty
.Add（FIELD_SomeField2，GetType（System.Double））.DefaultValue=0
以
Dim键（1）作为数据列
键（0）=列（字段\字段1）
TableName=表名称
PrimaryKey=密钥
端接头
末级

我目前正在与EF合作，所以在我的razzle中，我写了如下内容（是的，是vb）：

部分公共类SomeTable1
继承数据表
好友属性SomePK1作为数据列
Friend属性SomeField1作为DataColumn
Friend属性SomeField2作为DataColumn
...
受保护的子新建（ByVal信息作为SerializationInfo，ByVal上下文作为StreamingContext）
MyBase.New（信息、上下文）
端接头
公共分新（）
MyBase.New（）
SomeField2=日期。现在
端接头
末级

我梦想着做一些与以前的dt相当的东西，并与当前的数据引擎完全兼容

然后类型转换错误（系统日期到数据列）打破了我的希望。我必须承认这是一个艰难的周末：）

所以在我完全放弃更改之前，是否有任何方法可以编写一个类型化的数据表，这样它就等同于上面的代码，但有一些新的优点？ 这是一种非常古老的编程方式，我在网上找不到任何东西。

---

提前感谢。

我不确定是否完全理解，但看起来您将FIELD\u SomeField2定义为双精度字段

（第一段中的这一行）

但我看到您在第二个代码片段中将SomeField2定义为日期时间

<Required()>
<DataType(DataType.DateTime)>
Friend Property SomeField2 As DataColumn

Friend属性SomeField2作为DataColumn

---

所以可能只是类型不匹配…

我找到了如何做我想做的事。也许需要一些工作，但它是有效的。 我知道这是一种过时的做事方式，所以我在这里发帖是为了让像我这样被迫维护旧程序的人受益

执行类型化数据表的模板如下所示：

Imports System.Data
Imports System.ComponentModel
Imports System.Runtime.Serialization
Imports System.Diagnostics

'''<summary>
'''Represents the strongly named DataTable class.
'''</summary>
<Global.System.Serializable(), _
 Global.System.Xml.Serialization.XmlSchemaProviderAttribute("GetTypedTableSchema")> _
Partial Public Class tblMyTable
    Inherits TypedTableBase(Of tblMyTableRow)

    'Those are the StoredProcs names for (MANUAL) CRUD operations that the DBContext wrapper uses. (yuck! I hate thousands of them)
    'Public Const COMMAND_SAVE As String = "sp_MyTable_Save"
    'Public Const COMMAND_DELETE As String = "sp_MyTable_Delete"
    'Public Const COMMAND_LOADBY_ID As String = "sp_MyTable_LoadBy_Id"

    'Those are constants I maintain for untyped (but somewhat strong) compatibility
    Public Const FIELD_pID As String = "pID"
    Public Const FIELD_SomeOther As String = "SomeOtherField"

    'Basic CRUD, uses company data as the app hot swapps DBs (one for company)
    'Public Function Save(ByVal company As DataRow) As Short
    '    Return New Base(company).Update(Me, COMMAND_SAVE, COMMAND_DELETE)
    'End Function

    'Public Sub LoadByID(ByVal company As DataRow, Id As Integer)
    '    Me.Rows.Clear()
    '    Me.Merge(New Base(company).FillDataTable(Of tblMyTable)(COMMAND_LOADBY_ID, Id))
    'End Sub

    <DebuggerNonUserCodeAttribute()>
    Private Sub InitClass()
        Me.columnpID = New DataColumn(FIELD_pID, GetType(Integer), Nothing, MappingType.Element) With
                   {.AllowDBNull = False, .ReadOnly = True, .Unique = True,
                    .AutoIncrement = True, .AutoIncrementSeed = -1, .AutoIncrementStep = -1}
        MyBase.Columns.Add(Me.columnpID)
        Me.columnSomeOtherField = New DataColumn(FIELD_SomeOther, GetType(String), Nothing, MappingType.Element) With
                           {.MaxLength = 5, .AllowDBNull = False, .DefaultValue = String.Empty}
        MyBase.Columns.Add(Me.columnSomeOtherField)
    End Sub

    Private columnpID As DataColumn
    Private columnSomeOtherField As DataColumn

    <DebuggerNonUserCodeAttribute()>
    Public Sub New()
        MyBase.New()
        Me.TableName = "tblMyTable"
        Me.BeginInit()
        Me.InitClass()
        Me.EndInit()
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Friend Sub New(ByVal table As DataTable)
        MyBase.New()
        Me.TableName = table.TableName
        If (table.CaseSensitive <> table.DataSet.CaseSensitive) Then
            Me.CaseSensitive = table.CaseSensitive
        End If
        If (table.Locale.ToString <> table.DataSet.Locale.ToString) Then
            Me.Locale = table.Locale
        End If
        If (table.Namespace <> table.DataSet.Namespace) Then
            Me.Namespace = table.Namespace
        End If
        Me.Prefix = table.Prefix
        Me.MinimumCapacity = table.MinimumCapacity
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Protected Sub New(ByVal info As Global.System.Runtime.Serialization.SerializationInfo, ByVal context As Global.System.Runtime.Serialization.StreamingContext)
        MyBase.New(info, context)
        Me.InitVars()
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Public ReadOnly Property pIDColumn() As DataColumn
        Get
            Return Me.columnpID
        End Get
    End Property

    <DebuggerNonUserCodeAttribute()>
    Public ReadOnly Property SomeOtherFieldColumn() As DataColumn
        Get
            Return Me.columnSomeOtherField
        End Get
    End Property

    <DebuggerNonUserCodeAttribute(), Browsable(False)>
    Public ReadOnly Property Count() As Integer
        Get
            Return Me.Rows.Count
        End Get
    End Property

    <DebuggerNonUserCodeAttribute()>
    Default Public ReadOnly Property Item(ByVal index As Integer) As tblMyTableRow
        Get
            Return CType(Me.Rows(index), tblMyTableRow)
        End Get
    End Property

    <DebuggerNonUserCodeAttribute()>
    Public Overrides Function Clone() As DataTable
        Dim cln As tblMyTable = CType(MyBase.Clone, tblMyTable)
        cln.InitVars()
        Return cln
    End Function

    <DebuggerNonUserCodeAttribute()>
    Protected Overrides Function CreateInstance() As DataTable
        Return New tblMyTable()
    End Function

    <DebuggerNonUserCodeAttribute()>
    Friend Sub InitVars()
        Me.columnpID = MyBase.Columns(FIELD_pID)
        Me.columnSomeOtherField = MyBase.Columns(FIELD_SomeOther)
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Public Function NewtblMyTableRow() As tblMyTableRow
        Return CType(Me.NewRow, tblMyTableRow)
    End Function

    <DebuggerNonUserCodeAttribute()>
    Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
        Return New tblMyTableRow(builder)
    End Function

    <DebuggerNonUserCodeAttribute()>
    Protected Overrides Function GetRowType() As Global.System.Type
        Return GetType(tblMyTableRow)
    End Function

    <DebuggerNonUserCodeAttribute()>
    Public Sub RemovetblMyTableRow(ByVal row As tblMyTableRow)
        Me.Rows.Remove(row)
    End Sub

End Class

'''<summary>
'''Represents strongly named DataRow class.
'''</summary>
Partial Public Class tblMyTableRow
    Inherits DataRow

    Private tabletblMyTable As tblMyTable

    <DebuggerNonUserCodeAttribute()>
    Friend Sub New(ByVal rb As DataRowBuilder)
        MyBase.New(rb)
        Me.tabletblMyTable = CType(Me.Table, tblMyTable)
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Public Property pID() As Integer
        Get
            Return CType(Me(Me.tabletblMyTable.pIDColumn), Integer)
        End Get
        Set(value As Integer)
            Me(Me.tabletblMyTable.pIDColumn) = value
        End Set
    End Property

    <DebuggerNonUserCodeAttribute()>
    Public Property SomeOtherField() As String
        Get
            Return CType(Me(Me.tabletblMyTable.SomeOtherFieldColumn), String)
        End Get
        Set(value As String)
            Me(Me.tabletblMyTable.SomeOtherFieldColumn) = value
        End Set
    End Property
End Class

导入系统数据
导入System.ComponentModel
导入System.Runtime.Serialization
导入系统。诊断
'''
''表示强命名的DataTable类。
'''
_
部分公共类tblMyTable
继承TypedTableBase（属于tblMyTableRow）
'这些是DBContext包装器使用的（手动）CRUD操作的StoredProcs名称。（恶心！我讨厌成千上万的人）
'Public Const COMMAND_SAVE As String=“sp_MyTable_SAVE”
'Public Const COMMAND_DELETE As String=“sp_MyTable_DELETE”
'Public Const COMMAND\u LOADBY\u ID As String=“sp\u MyTable\u LOADBY\u ID”
“这些是我为实现非类型化（但有点强）兼容性而维护的常量
公用常量字段\u pID为String=“pID”
Public Const FIELD_SomeOther As String=“SomeOtherField”
“基本CRUD，使用公司数据作为应用程序热交换DBs（一个用于公司）
'公共函数保存（ByVal公司作为数据行）为短
'返回新基地（公司）。更新（Me、命令保存、命令删除）
'结束函数
'公共子加载BYID（ByVal公司作为数据行，Id作为整数）
“我。行。清除（）
'Me.Merge（新基（公司）.FillDataTable（属于tblMyTable）（命令\u LOADBY\u ID，ID））
'末端接头
私有子类（）
Me.columnpID=带有
{.AllowDBNull=False、.ReadOnly=True、.Unique=True、，
.AutoIncrement=True，.AutoIncrementSeed=-1，.AutoIncrementStep=-1}
MyBase.Columns.Add（Me.columnpID）
Me.columnsometherfield=newdatacolumn（FIELD_somether，GetType（String），Nothing，MappingType.Element）与
{.MaxLength=5、.AllowDBNull=False、.DefaultValue=String.Empty}
MyBase.Columns.Add（Me.columnsometherfield）
端接头
作为数据列的私有列PID
Private ColumnSometherField作为DataColumn
公共分新（）
MyBase.New（）
Me.TableName=“tblMyTable”
Me.BeginInit（）
Me.InitClass（）
Me.EndInit（）
端接头
Friend Sub New（ByVal表作为DataTable）
MyBase.New（）
Me.TableName=table.TableName
如果（table.CaseSensitive table.DataSet.CaseSensitive），则
Me.CaseSensitive=table.CaseSensitive
如果结束
如果（table.Locale.ToString table.DataSet.Locale.ToString），则
Me.Locale=table.Locale
如果结束
如果是（table.Namespace table.DataSet.Namespace），则
Me.Namespace=table.Namespace
如果结束
Me.Prefix=table.Prefix
Me.MinimumCapacity=表1.MinimumCapacity
端接头
受保护的子新建（ByVal信息为Global.System.Runtime.Serialization.SerializationInfo，ByVal上下文为Global.System.Runtime.Serialization.StreamingContext）
MyBase.New（信息、上下文）
Me.InitVars（）
端接头
作为DataColumn的公共只读属性pIDColumn（）
得到
还给我
结束
端属性
作为DataColumn的公共只读属性SomeOtherFieldColumn（）
得到
返回我。其他字段
结束
端属性
公共只读属性计数（）为整数
<Required()>
<DataType(DataType.DateTime)>
Friend Property SomeField2 As DataColumn

Imports System.Data
Imports System.ComponentModel
Imports System.Runtime.Serialization
Imports System.Diagnostics

'''<summary>
'''Represents the strongly named DataTable class.
'''</summary>
<Global.System.Serializable(), _
 Global.System.Xml.Serialization.XmlSchemaProviderAttribute("GetTypedTableSchema")> _
Partial Public Class tblMyTable
    Inherits TypedTableBase(Of tblMyTableRow)

    'Those are the StoredProcs names for (MANUAL) CRUD operations that the DBContext wrapper uses. (yuck! I hate thousands of them)
    'Public Const COMMAND_SAVE As String = "sp_MyTable_Save"
    'Public Const COMMAND_DELETE As String = "sp_MyTable_Delete"
    'Public Const COMMAND_LOADBY_ID As String = "sp_MyTable_LoadBy_Id"

    'Those are constants I maintain for untyped (but somewhat strong) compatibility
    Public Const FIELD_pID As String = "pID"
    Public Const FIELD_SomeOther As String = "SomeOtherField"

    'Basic CRUD, uses company data as the app hot swapps DBs (one for company)
    'Public Function Save(ByVal company As DataRow) As Short
    '    Return New Base(company).Update(Me, COMMAND_SAVE, COMMAND_DELETE)
    'End Function

    'Public Sub LoadByID(ByVal company As DataRow, Id As Integer)
    '    Me.Rows.Clear()
    '    Me.Merge(New Base(company).FillDataTable(Of tblMyTable)(COMMAND_LOADBY_ID, Id))
    'End Sub

    <DebuggerNonUserCodeAttribute()>
    Private Sub InitClass()
        Me.columnpID = New DataColumn(FIELD_pID, GetType(Integer), Nothing, MappingType.Element) With
                   {.AllowDBNull = False, .ReadOnly = True, .Unique = True,
                    .AutoIncrement = True, .AutoIncrementSeed = -1, .AutoIncrementStep = -1}
        MyBase.Columns.Add(Me.columnpID)
        Me.columnSomeOtherField = New DataColumn(FIELD_SomeOther, GetType(String), Nothing, MappingType.Element) With
                           {.MaxLength = 5, .AllowDBNull = False, .DefaultValue = String.Empty}
        MyBase.Columns.Add(Me.columnSomeOtherField)
    End Sub

    Private columnpID As DataColumn
    Private columnSomeOtherField As DataColumn

    <DebuggerNonUserCodeAttribute()>
    Public Sub New()
        MyBase.New()
        Me.TableName = "tblMyTable"
        Me.BeginInit()
        Me.InitClass()
        Me.EndInit()
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Friend Sub New(ByVal table As DataTable)
        MyBase.New()
        Me.TableName = table.TableName
        If (table.CaseSensitive <> table.DataSet.CaseSensitive) Then
            Me.CaseSensitive = table.CaseSensitive
        End If
        If (table.Locale.ToString <> table.DataSet.Locale.ToString) Then
            Me.Locale = table.Locale
        End If
        If (table.Namespace <> table.DataSet.Namespace) Then
            Me.Namespace = table.Namespace
        End If
        Me.Prefix = table.Prefix
        Me.MinimumCapacity = table.MinimumCapacity
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Protected Sub New(ByVal info As Global.System.Runtime.Serialization.SerializationInfo, ByVal context As Global.System.Runtime.Serialization.StreamingContext)
        MyBase.New(info, context)
        Me.InitVars()
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Public ReadOnly Property pIDColumn() As DataColumn
        Get
            Return Me.columnpID
        End Get
    End Property

    <DebuggerNonUserCodeAttribute()>
    Public ReadOnly Property SomeOtherFieldColumn() As DataColumn
        Get
            Return Me.columnSomeOtherField
        End Get
    End Property

    <DebuggerNonUserCodeAttribute(), Browsable(False)>
    Public ReadOnly Property Count() As Integer
        Get
            Return Me.Rows.Count
        End Get
    End Property

    <DebuggerNonUserCodeAttribute()>
    Default Public ReadOnly Property Item(ByVal index As Integer) As tblMyTableRow
        Get
            Return CType(Me.Rows(index), tblMyTableRow)
        End Get
    End Property

    <DebuggerNonUserCodeAttribute()>
    Public Overrides Function Clone() As DataTable
        Dim cln As tblMyTable = CType(MyBase.Clone, tblMyTable)
        cln.InitVars()
        Return cln
    End Function

    <DebuggerNonUserCodeAttribute()>
    Protected Overrides Function CreateInstance() As DataTable
        Return New tblMyTable()
    End Function

    <DebuggerNonUserCodeAttribute()>
    Friend Sub InitVars()
        Me.columnpID = MyBase.Columns(FIELD_pID)
        Me.columnSomeOtherField = MyBase.Columns(FIELD_SomeOther)
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Public Function NewtblMyTableRow() As tblMyTableRow
        Return CType(Me.NewRow, tblMyTableRow)
    End Function

    <DebuggerNonUserCodeAttribute()>
    Protected Overrides Function NewRowFromBuilder(ByVal builder As DataRowBuilder) As DataRow
        Return New tblMyTableRow(builder)
    End Function

    <DebuggerNonUserCodeAttribute()>
    Protected Overrides Function GetRowType() As Global.System.Type
        Return GetType(tblMyTableRow)
    End Function

    <DebuggerNonUserCodeAttribute()>
    Public Sub RemovetblMyTableRow(ByVal row As tblMyTableRow)
        Me.Rows.Remove(row)
    End Sub

End Class

'''<summary>
'''Represents strongly named DataRow class.
'''</summary>
Partial Public Class tblMyTableRow
    Inherits DataRow

    Private tabletblMyTable As tblMyTable

    <DebuggerNonUserCodeAttribute()>
    Friend Sub New(ByVal rb As DataRowBuilder)
        MyBase.New(rb)
        Me.tabletblMyTable = CType(Me.Table, tblMyTable)
    End Sub

    <DebuggerNonUserCodeAttribute()>
    Public Property pID() As Integer
        Get
            Return CType(Me(Me.tabletblMyTable.pIDColumn), Integer)
        End Get
        Set(value As Integer)
            Me(Me.tabletblMyTable.pIDColumn) = value
        End Set
    End Property

    <DebuggerNonUserCodeAttribute()>
    Public Property SomeOtherField() As String
        Get
            Return CType(Me(Me.tabletblMyTable.SomeOtherFieldColumn), String)
        End Get
        Set(value As String)
            Me(Me.tabletblMyTable.SomeOtherFieldColumn) = value
        End Set
    End Property
End Class