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sorry , but why the method Clone is not added as extension ? Have I done something wrong constructing the extension ?
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Wow an I tired. It's 2:00am here. I didn't even notice the Clone method name...
What does your MyObject class look like? Are you using Database First, Code First, or what?
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I'm using Database First.
Partial Public Class Myobject
Public Property id As Integer
Public property name as string
Public Overridable Property chld As ICollection(Of chld) = New HashSet(Of chld)
End Class
Partial Public Class chld
Public Property id As Integer
Public Property date1 as DateTime
Public Property quantity as Integer
Public Property ParentID as integer
Public Overridable Property MyObj1 As MyObject
End Class
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It doesn't work because Database First entity objects inherit from Object, not EntityObject. Your current Close method would work just fine for a Code First EF model.
The only way to get the Clone() to work is to remove the "As EntityObject" restriction in the function header. Of course, this is going to make your Clone() method available for every type in the application.
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I remove the "As entityobject".
Now , on runtime , I get this error on the line : ser.WriteObject(stream, source) :
An unhandled exception of type 'System.Runtime.Serialization.SerializationException' occurred in System.Runtime.Serialization.dll
Additional information: Type 'System.Data.Entity.DynamicProxies.MyObject_F2FFE64DA472EB2B2BDF7E143DE887D3845AD9D1731FD3107937062AC0C2E4BB' with data contract name 'MyObject_F2FFE64DA472EB2B2BDF7E143DE887D3845AD9D1731FD3107937062AC0C2E4BB:http://schemas.datacontract.org/2004/07/System.Data.Entity.DynamicProxies' is not expected. Consider using a DataContractResolver or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to DataContractSerializer.
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I don't know what you've got wrong because I can't replicated it.
This is the modified extension code I used:
Imports System.Data.Entity.Core.Objects.DataClasses
Imports System.Runtime.Serialization
Imports System.IO
Imports System.Runtime.CompilerServices
Imports System.Data.Objects
Module Extensions
<Extension>
Public Function Clone(Of T)(source As T) As T
Dim ser = New DataContractSerializer(GetType(T))
Using stream = New MemoryStream()
ser.WriteObject(stream, source)
stream.Seek(0, SeekOrigin.Begin)
Return CType(ser.ReadObject(stream), T)
End Using
End Function
End Module
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This exactly the same code that I have used. but I get the error that I have posted before.
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It just dawned on me why you're getting that error. The object you're trying to Clone is referencing other object in the database that haven't been re-hydrated by EF yet. That's where those strange looking proxy objects are coming from.
In order to get it to work, you have to load the objects being referenced before you try and Close the base object.
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The way I'm getting the object that i want to clone is this :
-I have a listbox bound to a bindingsource (that have as datasource = (From t in context.Myobjects where t.id>5 select t ).Tolist
- The user select several items from listbox.
- I have a listitm=New list(of Myobject) , where i add one by one the items selected from listbox.
- After i have the code that i posted to my question :
Dim litm, newitm as MyObject
For Each litm In itemlist
newitm = litm.Clone()
...
Next
so in this situation , do you have an idea why i have those strange looking proxy objects like : MyObject_F2FFE64DA472EB2B2BDF7E143DE887D3845AD9D1731FD3107937062AC0C2E4BB
Thank you !
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I just told you why. The object has a reference to another related object that EF hasn't loaded.
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Actually , i have loaded all referenced object , but i think some of them are loaded only with some of the properties.
MyObjects - ob1
I have loaded ob1 like below :
Myob1list=(From t in context.ob1s
Select t.id,t.name).Tolist
May be this the problem , and if yes , what should i do ?
Thank you !
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You have to load the child objects in your query:
Myob1list = (From t in context.ob1s.Include("chld")
Select t).ToList()
(I'm converting C# code from memory. I haven't touched VB.NET in a few years now.)
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Sorry , but I'm using lazyloading.
and I've read that these proxy objects , are related with using of lazyloading.
So , why all other actions that I do with my objects works without problems, and this Clone action produce errors ?
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dilkonika wrote: Sorry , but I'm using lazyloading.
and I've read that these proxy objects , are related with using of lazyloading.
Yeah, I can see that.
dilkonika wrote: So , why all other actions that I do with my objects works without problems, and this Clone action produce errors ?
Because the proxy classes are dynamically generated by EF and are not serializable.
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dilkonika wrote: Sorry , but I'm using lazyloading.
That doesn't mean you can't tell EF it should eager-load dependencies when you need it (which is what Include(..) does).
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yes , but when I call the extension , these objects are already loaded in the way that I have described.
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Hello I've managed to get the current tab for Google Chrome however how do I change that URL and made a navigation? I've done on IE but no luck for Opera and Firefox.
Example: Current urL: google.com will be yahoo.com upon active tab taken. Do I need to play something with the process of chrome? Thank you for any solution to be provide.
Dim procsChrome As Process() = Process.GetProcessesByName("chrome")
02
For Each chrome As Process In procsChrome
03
04
If chrome.MainWindowHandle = IntPtr.Zero Then Continue For
05
Dim elm As AutomationElement = AutomationElement.FromHandle(chrome.MainWindowHandle)
06
Dim elmUrlBar As AutomationElement = elm.FindFirst(TreeScope.Descendants, New PropertyCondition(AutomationElement.NameProperty, "Address and search bar"))
07
If elmUrlBar IsNot Nothing Then
08
Dim patterns As AutomationPattern() = elmUrlBar.GetSupportedPatterns()
09
If patterns.Length > 0 Then
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Dim val As ValuePattern = DirectCast(elmUrlBar.GetCurrentPattern(patterns(0)), ValuePattern)
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If Not elmUrlBar.GetCurrentPropertyValue(AutomationElement.HasKeyboardFocusProperty) Then
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MsgBox(LCase(val.Current.Value).Trim)
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End If
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Exit For
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End If
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End If
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Next
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Hello !
In vb.net 2013 , SQL server 2008R2 :
I have an active database , and a backup database ( .bak) file.
I want to compare the structure of these databases , to know if the structure is identical , if not to have a list with differencies
Can you give me some steps , how can I do this on Vb.net ?
Thank you !
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Ok , but I want to know if how to do this with code in vb.net.
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Mika gave you a direction; he is not going to give you the code.
if you show the code you've written and need help on a particular section, someone may help.
But, you are expected to provide the code you wrote first.
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Hi Tim,
I don't think dilkonika was asking for ready made code here. He/She asked quite a few questions in the last days and didn't show that kind of attitude; instead came up more than once with own code-attempts. Please read his/her reply again - there's a "if how" in there. I think he/she just didn't understand Mika's reply correctly or didn't pay enough attention. I assume you downvoted the reply, maybe you want to reconsider.
cheers, Sascha
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Sascha, replied but did not vote at all.
Thanks for the reply; hadn't seen previous posts from the OP.
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Alright 
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Sascha Lefévre wrote: I assume you downvoted the reply, maybe you want to reconsider.
No, I did, and I am not reconsidering.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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