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我想使用下面的实体框架代码更新表中的字段,但它似乎不会修改该字段。这真令人沮丧,所以我想知道是否有人能告诉我我做错了什么?使用实体框架更新表
default.aspx.vb:
Protected Sub btn_Save_Click(sender As Object, e As System.EventArgs) Handles btn_Save.Click
SaveNewsBox()
End Sub
Private Sub GetNewsBox()
Dim newsBox As GLC.Home = BLL.Homes.Homes.GetNewsBox()
If newsBox IsNot Nothing Then
txt_NewsBox.Text = newsBox.NewsBox
End If
End Sub
Private Sub SaveNewsBox()
Dim newsBox As New GLC.Home
newsBox.NewsBox = txt_NewsBox.Text
If BLL.Homes.Homes.Update(newsBox) Then
Master.AlertStyle = "alert-success"
Master.AlertMessage = "<i class=""fa fa-thumbs-o-up""></i> Meal details saved, <a href=""/secure/"">return to main menu.</a>"
Master.AlertVisible = True
Else
Master.AlertStyle = "alert-danger"
Master.AlertMessage = "<i class=""fa fa-thumbs-o-down""></i> Warning news box details could not be saved.</a>"
Master.AlertVisible = True
End If
End Sub
End Class
Homes.vb:
Imports DAL
Imports GLC
Namespace Homes
Public Class Homes
Public Shared Function GetNewsBox() As Home
Return MethodClasses.HomesHandler.GetNewsBox()
End Function
Public Shared Function Update(newsBox As Home) As Boolean
Return MethodClasses.HomesHandler.Update(newsBox)
End Function
End Class
End Namespace
HomesHandler.vb:
Imports GLC
Imports System.Linq.Dynamic
Namespace MethodClasses
Public Class HomesHandler
Public Shared Function GetNewsBox() As Home
Using context As New GLCContext
Try
Return context.Homes.Single()
Catch ex As Exception
Return Nothing
End Try
End Using
End Function
Public Shared Function Update(newsBox As Home) As Boolean
Dim newsBoxUpdated As Boolean = False
Using context As New GLCContext
Try
context.Homes.Attach(newsBox)
Dim entry = context.Entry(newsBox)
entry.State = EntityState.Modified
context.SaveChanges()
newsBoxUpdated = True
Catch ex As Exception
newsBoxUpdated = False
End Try
End Using
Return newsBoxUpdated
End Function
End Class
End Namespace
没有错误?至少你似乎没有提供newsBox的PK值,或者总是等于0的值。 – tschmit007 2015-02-10 13:02:50
如果你从Update()函数中删除了try/catch,你会得到一个错误吗?另外,你能分享你的模式吗? – theduck 2015-02-10 17:53:15