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Newbie Question - Please HELP!The following code isn't working and I don't understand the error. Would
someone please shed some light on what I'm doing wrong. Thanks. The error I recieve is: An unhandled exception of type 'System.NullReferenceException' occurred....additional information: Object reference not set to an instance of an object. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim key As Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey("SOFTWARE", True) key.DeleteSubKeyTree("TestTree1") End Sub Thanks, mike Try this:
Imports Microsoft.win32 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim reg As RegistryKey reg = Registry.LocalMachine.OpenSubKey("Software", True) If Not (reg Is Nothing) Then reg.DeleteSubKeyTree("TestTree1") End If reg.Close() End Sub This works perfectly for me Crouchie1998 BA (HONS) MCP MCSE I see. That does work. Thanks.
But why when I change "Software" to "VolumeCaches" do I get the "object reference not set to an instance of an object" on the reg.close() line - even when testtree1 is a valid key under VolumeCaches? -mike Show quoteHide quote "Crouchie1998" <crouchie1998@spamcop.net> wrote in message news:ebVIKq9OFHA.3356@TK2MSFTNGP12.phx.gbl... > Try this: > > Imports Microsoft.win32 > > Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As > System.EventArgs) Handles Button1.Click > > Dim reg As RegistryKey > > reg = Registry.LocalMachine.OpenSubKey("Software", True) > > If Not (reg Is Nothing) Then > reg.DeleteSubKeyTree("TestTree1") > End If > > reg.Close() > > End Sub > > This works perfectly for me > > Crouchie1998 > BA (HONS) MCP MCSE > > If the key does not exist, reg will be Nothing so that when you hit the
..close, you are trying to call a method with a Nothing object. Place the .close inside the if block where you check for nothing: If Not (reg Is Nothing) Then reg.DeleteSubKeyTree("TestTree1") rec.Close End If That makes sence, but why doesn't the code remove the key when
reg = Registry.LocalMachine.OpenSubKey("VolumeCaches", True) I create a key named TestTree1 in VolumeCaches and then run the code and it doesn't remove anything....is there something special about "VolumeCaches" that makes it's subkey's not removable by the code? I can manually remove keys from this location without issue.... -m Show quoteHide quote "Chris Dunaway" <dunaw***@gmail.com> wrote in message news:1112966193.164941.258970@z14g2000cwz.googlegroups.com... > If the key does not exist, reg will be Nothing so that when you hit the > .close, you are trying to call a method with a Nothing object. Place > the .close inside the if block where you check for nothing: > > If Not (reg Is Nothing) Then > reg.DeleteSubKeyTree("TestTree1") > rec.Close > End If > just to clsrify the current issue...this works:
---------------------------------------------------- Dim reg As RegistryKey reg = Registry.LocalMachine.OpenSubKey("SOFTWARE", True) If Not (reg Is Nothing) Then reg.DeleteSubKeyTree("TestTree1") reg.Close() End If -------------------------------------------------------- but this doesn't work: Dim reg As RegistryKey reg = Registry.LocalMachine.OpenSubKey("VolumeCaches", True) If Not (reg Is Nothing) Then reg.DeleteSubKeyTree("TestTree1") reg.Close() End If ---------------------------------------------------------------------------- TestTree1 exists in both subkeys. I recieve no error however the key is not removed under scenario 2. Imports Microsoft.Win32 is being referenced in both cases. I apprecieate everyone's help thusfar. Thanks, mike Show quoteHide quote "mikew" <thewitt***@yahoo.com> wrote in message news:%23EuoNKEPFHA.3668@TK2MSFTNGP14.phx.gbl... > That makes sence, but why doesn't the code remove the key when > reg = Registry.LocalMachine.OpenSubKey("VolumeCaches", True) > > I create a key named TestTree1 in VolumeCaches and then run the code and > it doesn't remove anything....is there something special about > "VolumeCaches" that makes it's subkey's not removable by the code? I can > manually remove keys from this location without issue.... > > -m > > > "Chris Dunaway" <dunaw***@gmail.com> wrote in message > news:1112966193.164941.258970@z14g2000cwz.googlegroups.com... >> If the key does not exist, reg will be Nothing so that when you hit the >> .close, you are trying to call a method with a Nothing object. Place >> the .close inside the if block where you check for nothing: >> >> If Not (reg Is Nothing) Then >> reg.DeleteSubKeyTree("TestTree1") >> rec.Close >> End If >> > > You could just do this:
If Not Reg Is Nothing Then reg.Close() Crouchie1998 BA (HONS) MCP MCSE I don't think that solves the problem....
Thanks, m Show quoteHide quote "Crouchie1998" <crouchie1998@spamcop.net> wrote in message news:%23DU8mpFPFHA.3988@tk2msftngp13.phx.gbl... > You could just do this: > > If Not Reg Is Nothing Then reg.Close() > > Crouchie1998 > BA (HONS) MCP MCSE > > You can try this:
Private Function DeleteRegistrySubKeyTree(ByVal sKey As String, ByVal sSubkey As String) As Boolean Dim reg As RegistryKey Dim rp As New RegistryPermission(RegistryPermissionAccess.AllAccess, sKey) rp.Assert() Try reg = Registry.LocalMachine.OpenSubKey(sKey, True) If Not (reg Is Nothing) Then reg.DeleteSubKeyTree(sSubkey) End If Catch ex As Exception Return False Finally If Not reg Is Nothing Then reg.Close() rp.RevertAssert() rp = Nothing End Try Return True End Function Usage: ------- 1) DeleteRegistrySubKeyTree("Software", "TestTree1") 2) If DeleteRegistrySubKeyTree("Software", "TestTree1") = True Then MessageBox.Show("Sub Key Tree Deleted Successfully", Me.Text) Else MessageBox.Show("Sub Key Tree Deletion failed", Me.Text) End If I hope this helps Crouchie1998 BA (HONS) MCP MCSE Forgot to add. You will need the following Import statements:
Imports Microsoft.win32 Imports System.Security.Permissions Crouchie1998 BA (HONS) MCP MCSE "Crouchie1998" <crouchie1998@spamcop.net> wrote in message sSubkey As String) As Booleannews:en16c3HPFHA.2824@TK2MSFTNGP10.phx.gbl... > You can try this: > > Private Function DeleteRegistrySubKeyTree(ByVal sKey As String, ByVal Dim reg As RegistryKey Dim rp As New RegistryPermission(RegistryPermissionAccess.AllAccess, sKey) rp.Assert() Try reg = Registry.LocalMachine.OpenSubKey(sKey, True) If Not (reg Is Nothing) Then reg.DeleteSubKeyTree(sSubkey) End If Catch ex As Exception Return False Finally If Not reg Is Nothing Then reg.Close() rp.RevertAssert() rp = Nothing End Try Return True End Function Usage: ------- 1) DeleteRegistrySubKeyTree("Software", "TestTree1") 2) If DeleteRegistrySubKeyTree("Software", "TestTree1") = True Then MessageBox.Show("Sub Key Tree Deleted Successfully", Me.Text) Else MessageBox.Show("Sub Key Tree Deletion failed", Me.Text) End If I hope this helps Crouchie1998 BA (HONS) MCP MCSE Does anyone have a clue why this fails when you pass VolumeCaches as the
sKey. As in...DeleteRegistrySubKeyTree("VolumeCaches", "TestTree1") When "TestTree1" is a legit key under VolumeCaches. I thought Crouchie hit it with the System.Security.Permissions references, but it still isn't working when the target is under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches Thanks, Mike Show quoteHide quote "Crouchie1998" <crouchie1998@spamcop.net> wrote in message news:OKFKU8HPFHA.164@TK2MSFTNGP12.phx.gbl... > Forgot to add. You will need the following Import statements: > > Imports Microsoft.win32 > Imports System.Security.Permissions > > Crouchie1998 > BA (HONS) MCP MCSE > > "Crouchie1998" <crouchie1998@spamcop.net> wrote in message > news:en16c3HPFHA.2824@TK2MSFTNGP10.phx.gbl... >> You can try this: >> >> Private Function DeleteRegistrySubKeyTree(ByVal sKey As String, ByVal > sSubkey As String) As Boolean > > Dim reg As RegistryKey > > Dim rp As New RegistryPermission(RegistryPermissionAccess.AllAccess, sKey) > rp.Assert() > > Try > reg = Registry.LocalMachine.OpenSubKey(sKey, True) > If Not (reg Is Nothing) Then > reg.DeleteSubKeyTree(sSubkey) > End If > Catch ex As Exception > Return False > > Finally > If Not reg Is Nothing Then reg.Close() > rp.RevertAssert() > rp = Nothing > End Try > > Return True > > End Function > > Usage: > ------- > > 1) DeleteRegistrySubKeyTree("Software", "TestTree1") > > 2) > > If DeleteRegistrySubKeyTree("Software", "TestTree1") = True Then > MessageBox.Show("Sub Key Tree Deleted Successfully", Me.Text) > Else > MessageBox.Show("Sub Key Tree Deletion failed", Me.Text) > End If > > I hope this helps > > Crouchie1998 > BA (HONS) MCP MCSE > > I see your problem
DeleteRegistrySubKeyTree("SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer ", "VolumeCaches") Crouchie1998 BA (HONS) MCP MCSE Thanks...your help was helpful... :)
This worked. DeleteRegistrySubKeyTree("SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches", "TestTree1") I thought I had tried that iteration but aparently not. Thanks again, m Show quoteHide quote "Crouchie1998" <crouchie1998@spamcop.net> wrote in message news:uEUJGpIPFHA.3076@tk2msftngp13.phx.gbl... >I see your problem > > DeleteRegistrySubKeyTree("SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer > ", "VolumeCaches") > > Crouchie1998 > BA (HONS) MCP MCSE > > 
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