//If comobox1 changes this event will fire
//that means we chose an Oracle client
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
//Find the keyitem in KEYS list wich name is equal the name selected in combobox1
//Nice LAMBDA!!!!
KeySturct keyitem = Keys.FirstOrDefault(x => x.Name == comboBox1.Text);
//And gives the Oracle client parameters into textbox1,2,3 ...the home (means a path in the copmputer)
//Gives back the NLS settings: NLS is national settings ie. AMERICA and char encoding like UNICODE etc like this: HUNGARIAN_HUNGARY.EE8MSWIN1250 ...
//Textboxes are readonly: we cannot modify parameters, just see them, and set the default Oracle client with this program.
textBox1.Text = keyitem.Home;
textBox2.Text = keyitem.Nls;
textBox3.Text = keyitem.Id;
}
static List <KeySturct> LoadHomes()
{
var keys = new List <KeySturct>();
// Get current user's identity (me)
//If the user is an administrator, then let start the program
//Key is a registrykey type
RegistryKey key = null;
//subkey where the Oracle puts its informations.
//@ means to ignore the \ sign in string.
var subkeys = new [] { @"SOFTWARE\WOW6432Node\ORACLE", @"SOFTWARE\ORACLE" };
try
{
foreach (var subkey in subkeys)
{
//Try to open the registry key: HKLM\SOFTWARE\ORACLE with READ access: the false means the read permission
key = Registry.LocalMachine.OpenSubKey(subkey, false);
//If key not exists, or something wrong: ie not have permission to open this key... But here I must be an administrator.
if (key == null)
{
continue;
//There isn'Oracle in registry...opens messagebox with OK button
//MessageBox.Show(Resources.Message_NoOracleHomes, Resources.Message_Error,
//MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxDefaultButton.Button1);
//and returns to main form.
//return keys;
}
//If REgistry key open was successfull, then iterate on Subkey_names
foreach (var item in key.GetSubKeyNames())
{
// Oracle client informations are in subkeys like folders. And folder names start with HOME in older Oracle clients, and KEY in newer clients.
//ie. HOME1 with Client version 9
//and Key-Orahome1... with 11 or 12 version
//I put keynames into lower to avoid case sensitive problems in string comparisons
if (item.ToLower().StartsWith("home") || item.ToLower().StartsWith("key"))
{
//Item name \\ means \
var mykey = subkey + "\\" + item;
//Opens subkey to read client informations. Write access not necessary (false)
var orakey = Registry.LocalMachine.OpenSubKey(mykey, false);
//keyitem is a struct type
if (orakey != null)
{
var keyitem = new KeySturct
{
Key = orakey,
Name = (string)orakey.GetValue("ORACLE_HOME_NAME", null),
Home = (string)orakey.GetValue("ORACLE_HOME", null)
};
//read parameters from registry, and copy into keyitem, what is a type of keystruct.
keyitem.Bin = keyitem.Home + @"\bin";
keyitem.Nls = (string)orakey.GetValue("NLS_LANG", null);
keyitem.Id = (string)orakey.GetValue("ID", null);
//Adding keyitem to a keystruct LIST
keys.Add(keyitem);
//...and adding the name to combobox1 items. We can select names from combobox1
//comboBox1.Items.Add(keyitem.Name);
}
}
}
//If there isn't ALL_HOMES, the select the first in the combobox1
//There is a bug in program: if there isn't ALL_HOMES the the program gives back the first client in the list, and not the default client
//In newer Oracle clients has no ALL_HOMES in registry.
//But this is not a very big problem: if we use this program, set the Oracle client as we wish, and this program will WRITE ALL_HOMES key like in old Oracle versions.
//And next time this program will work well. So this is a very first running problem with newer Oracle clients.
}
//Older oracle versions has HKLM\SOFTWARE\ORACLE\ALL_HOMES key. Newer ones has not
var allhomes = subkeys[0] + "\\ALL_HOMES";
//Trying to read the deafultkey from ALL_HOMES
//Makes Defaultkey what is a registrykey
var defaultkey = Registry.LocalMachine.OpenSubKey(allhomes, false);
//If ALL_HOMES key EXISTS then
if (defaultkey != null)
{
//gets the defaulthome name from defaultkey
var defaulthome = (string)defaultkey.GetValue("DEFAULT_HOME", null);
//Select the keyitem from KEYS list, which name is equal the default home name
//Nice, nice, LAMBDA expression!!!!
//Not easy... try to understand : https://msdn.microsoft.com/en-us/library/bb397687.aspx
var i = 0;
for (; i < keys.Count; i++)
{
if (keys[i].Name == defaulthome)
{
break;
}
}
if (i < keys.Count)
{
var x = keys[i];
x.IsDefault = true;
keys[i] = x;
}
//Set the combobox1, the home-name selector default value the default home name
//comboBox1.Text = keyitem.Name;
}
}
//If something is wrong...
catch (Exception ex)
{
//Messagebox with OK button
MessageBox.Show(ex.Message, Resources.Message_Error, MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxDefaultButton.Button1);
}
// and we close the Registry key after this session
finally
{
key?.Close();
}
return(keys);
}