Use c# code to access the registry, can not modify the data to the registry

[Anastasia Barad]

What I want to achieve is to hide and show desktop icons by modifying the registry.
Other code will not be written, the main code is as follows:

try
{
int i = 1;
RegistryKey key = Registry.CurrentUser;
RegistryKey hide = key.OpenSubKey(@"Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced", true);
hide.SetValue("HideIcons",i, RegistryValueKind.DWord);
key.Close();
Process[] MyProcess = Process.GetProcessesByName("explorer");
MyProcess[0].Kill();
}
catch (Exception ex)
{
MessageBox.Show("Error!!! \n" + ex);
}

Now it is possible to modify it, but changing i=1 to i=0 is not possible. The default registry value is 0; that is, you cannot write 0.

 

[CodeMonkeyJ]

That's a tricky one. You can also try:

hide.DeleteValue("HideIcons");

But, that's not working for me, either, for that specific registry (writing zeroes and deleting works for arbitrarily named registries). Explorer seems to re-create it when it's restarted based on information elsewhere. Is there another registry to do accomplish this?

 

[Anastasia Barad]

I solved the problem by this method.

Int32 tempInt = 0; //predefine a signed 32-bit number
//conversion within the unchecked statement block, no overflow check
unchecked
{
tempInt = Convert.ToInt32("fffffffff", 16); //force conversion to a signed 32-bit number
}
//at this point the tempInt is already a signed 32-bit number and can be written directly to the registry
SetValue("HideIcons",tempInt, RegistryValueKind.DWord);

 

[CodeMonkeyJ]

Excellent, I'm glad you got it working! Your solution still throws an OverflowException for me, which should be impossible. I'd imagine it's not worth figuring out, though. On my end, the zero is taking hold but Explorer is reloading the one about 200ms after being killed. I used the following loop to watch for it.

int j = 0;
for (; j < 100; j++)
{
    Thread.Sleep(10);
    Console.WriteLine(hide.GetValue("HideIcons"));
    if (hide.GetValue("HideIcons").ToString() == "1")
    {
        break;
    }
}
Console.WriteLine(j * 10 + " ms");

Again, hardly seems worth understanding if you've got it working. Well done.