为什么尝试更新注册表值会失败？

Question

我有这个代码：

RegistryKey myKey = Registry.LocalMachine.OpenSubKey("SOFTWARE\Android Studio", true);
myKey.SetValue("StartMenuGroup", "Droidio", RegistryValueKind.String); // was "Android Studio" - change to "Droidio"

...我改编自 here.

运行它，尽管会导致以下 NRE 转储：

*System.NullReferenceException was unhandled
  _HResult=-2147467261
  _message=Object reference not set to an instance of an object.
  HResult=-2147467261
  IsTransient=false
  Message=Object reference not set to an instance of an object.
  Source=Sandbox
  StackTrace:
       at Sandbox.Form1.button57_Click(Object sender, EventArgs e) in c:\HoldingTank\Sandbox\Form1.cs:line 2524
       at System.Windows.Forms.Control.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ButtonBase.WndProc(Message& m)
       at System.Windows.Forms.Button.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at Sandbox.Program.Main() in c:\HoldingTank\Sandbox\Program.cs:line 19
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:*

我正在尝试更新的注册表设置（作为测试；然后我会重新设置）在这里：

当注册表项明明存在时，这怎么会失败？

更新

我尝试了另一种方法，我改编自 here:

RegistryKey reg32key = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, 
    RegistryView.Registry32);
RegistryKey reg_32bit_AppKey = 
    reg32key.OpenSubKey(@"HKEY_LOCAL_MACHINE\SOFTWARE\Android Studio");
if (reg_32bit_AppKey != null)
{
    MessageBox.Show(String.Format("value was {0}", 
        reg_32bit_AppKey.GetValue("StartMenuGroup").ToString()));
    reg_32bit_AppKey.SetValue("StartMenuGroup", "Droidio");
    MessageBox.Show(String.Format("value is now {0}", 
        reg_32bit_AppKey.GetValue("StartMenuGroup").ToString()));
}
else
{
    MessageBox.Show("Cannot open registry");
}

...但是，虽然它没有崩溃，但我看到了“无法打开注册表”消息。

更新 2

有了这个（位数加倍）：

RegistryKey reg64key = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, 
    RegistryView.Registry64);
RegistryKey reg_64bit_AppKey = 
    reg64key.OpenSubKey(@"HKEY_LOCAL_MACHINE\SOFTWARE\Android Studio");
if (reg_64bit_AppKey != null)
{
    MessageBox.Show(String.Format("value was {0}", 
        reg_64bit_AppKey.GetValue("StartMenuGroup").ToString()));
    reg_64bit_AppKey.SetValue("StartMenuGroup", "Droidio");
    MessageBox.Show(String.Format("value is now {0}", 
        reg_64bit_AppKey.GetValue("StartMenuGroup").ToString()));
}
else
{
    MessageBox.Show("Cannot open registry");
}

...我仍然得到“无法打开注册表”结果。

更新 3

好的，将代码更改为此（从替代尝试中删除 "HKEY_LOCAL_MACHINE"）：

RegistryKey reg64key = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, 
    RegistryView.Registry64);
RegistryKey reg_64bit_AppKey = reg64key.OpenSubKey(@"SOFTWARE\Android 
    Studio");
if (reg_64bit_AppKey != null)
{
    MessageBox.Show(String.Format("value was {0}", 
        reg_64bit_AppKey.GetValue("StartMenuGroup").ToString()));
    reg_64bit_AppKey.SetValue("StartMenuGroup", "Droidio");
    MessageBox.Show(String.Format("value is now {0}", 
        reg_64bit_AppKey.GetValue("StartMenuGroup").ToString()));
}
else
{
    MessageBox.Show("Cannot open registry");
}

...更改异常。首先，正如我所见，“价值是 Android Studio”

...但随后在下一行中断，即：

reg_64bit_AppKey.SetValue("StartMenuGroup", "Droidio");

...与：

*System.UnauthorizedAccessException was unhandled
  _HResult=-2147024891
  _message=Cannot write to the registry key.
  HResult=-2147024891
  IsTransient=false
  Message=Cannot write to the registry key.
  Source=mscorlib
  StackTrace:
       at System.ThrowHelper.ThrowUnauthorizedAccessException(ExceptionResource resource)
       at Microsoft.Win32.RegistryKey.EnsureWriteable()
       at Microsoft.Win32.RegistryKey.SetValue(String name, Object value, RegistryValueKind valueKind)
       at Microsoft.Win32.RegistryKey.SetValue(String name, Object value)
       at Sandbox.Form1.button57_Click(Object sender, EventArgs e) in c:\HoldingTank\Sandbox\Form1.cs:line 2559
       at System.Windows.Forms.Control.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ButtonBase.WndProc(Message& m)
       at System.Windows.Forms.Button.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at 
System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentM
anager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at Sandbox.Program.Main() in c:\HoldingTank\Sandbox\Program.cs:line 19
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object 
state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, 
Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException:*

那么为什么我可以读，但不能写？我运行ning Visual Studio 2013 处于管理员模式，因为我运行此代码...

更新 4

现在是未授权访问问题。

这是 reg_64bit_AppKey 的值，因为我到达了设置值的行：

F10 通过它咳出 "Unauthorized access" 呜呜声[g]ing。

更新 5

正在创建包含以下内容的文件：

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Android Studio]

"StartMenuGroup"="Droidio"

...将其命名为“DroidioReg.reg”，然后从 Windows 中手动选择合并上下文菜单，Explorer 完成了我的预期（无论如何希望): 将 StartMenuGroup 的值更改为 "Droidio"。实际上，即使只是双击文件并在所有确认对话框中移动也可以。

所以，这是第 N 度的笨拙，但是否可以通过编程方式调用该文件的 "Merge" - IOW，将该文件放在手持设备上，然后在代码中执行它？用户是否必须浏览警告对话框，或者是否有办法以编程方式阻止显示这些对话框？

Answer 1

使用转义字符串而不是字符串文字。 OpenSubKey 方法似乎无法正确读取您的转义路径。

Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Android Studio", true);

Answer 2

我在 Pwninstein 的评论中找到了克服访问权限侵犯的关键点 here - 只需将 "true" 附加到 OpenSubKey() 方法即可。

我被吓到了，但现在我可以吹嘘通过 tWotC（人群的智慧）组装的工作代码是：

RegistryKey reg64key = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64);
RegistryKey reg_64bit_AppKey = reg64key.OpenSubKey(@"SOFTWARE\Android Studio", true);
if (reg_64bit_AppKey != null)
{
    //MessageBox.Show(String.Format("value was {0}", reg_64bit_AppKey.GetValue("StartMenuGroup")));
    reg_64bit_AppKey.SetValue("StartMenuGroup", "Droidio", RegistryValueKind.String);
    //MessageBox.Show(String.Format("value is now {0}", reg_64bit_AppKey.GetValue("StartMenuGroup")));
}
else
{
    MessageBox.Show("Cannot open registry");
}

对于我的真实案例，我无疑需要使用 32 位版本，而不是 64 位版本，因为手持设备比 Joe Dirt 老，而且脾气暴躁两倍。

为什么尝试更新注册表值会失败？

Why does this Attempt to Update a Registry Value Fail?

c#

registry

regedit

registrykey

更新

更新 2

更新 3

更新 4

更新 5