using Microsoft.Win32;

RegistryKey key = Registry.LocalMachine;
RegistryKey software = key.CreateSubKey("software\\test");
//在HKEY_LOCAL_MACHINE\SOFTWARE下新建名为test的注册表项。如果已经存在则不影响！

RegistryKey key = Registry.LocalMachine;
RegistryKey software = key.OpenSubKey("software\\test",true);
//注意该方法后面还可以有一个布尔型的参数，true表示可以写入。

RegistryKey key = Registry.LocalMachine;
key.DeleteSubKey("software\\test",true); //该方法无返回值，直接调用即可
key.Close();

RegistryKey key = Registry.LocalMachine;
RegistryKey software = key.OpenSubKey("software\\test",true); //该项必须已存在
software.SetValue("test", "博客园");
//在HKEY_LOCAL_MACHINE\SOFTWARE\test下创建一个名为“test”，值为“博客园”的键值。如果该键值原本已经存在，则会修改替换原来的键值，如果不存在则是创建该键值。
// 注意：SetValue()还有第三个参数，主要是用于设置键值的类型，如：字符串，二进制，Dword等等~~默认是字符串。如：
// software.SetValue("test", "0", RegistryValueKind.DWord); //二进制信息
Key.Close();

string info = "";
RegistryKey Key;
Key = Registry.LocalMachine;
myreg = Key.OpenSubKey("software\\test");
// myreg = Key.OpenSubKey("software\\test",true);
info = myreg.GetValue("test").ToString();
myreg.Close();

RegistryKey delKey = Registry.LocalMachine.OpenSubKey("Software\\test", true);
delKey.DeleteValue("test");
delKey.Close();

private bool IsRegeditItemExist()  
{  
    string [] subkeyNames;  
    RegistryKey hkml = Registry.LocalMachine;  
    RegistryKey software = hkml.OpenSubKey("SOFTWARE");  
    //RegistryKey software = hkml.OpenSubKey("SOFTWARE", true);  
    subkeyNames = software.GetSubKeyNames();  
    //取得该项下所有子项的名称的序列，并传递给预定的数组中  
    foreach (string keyName in subkeyNames)   
    //遍历整个数组  
    {  
        if (keyName == "test")  
        //判断子项的名称  
        {   
            hkml.Close();  
            return true ;  
        }  
    }  
    hkml.Close();  
    return false;   
}

private bool IsRegeditKeyExit()
{
  string[] subkeyNames;
  RegistryKey hkml = Registry.LocalMachine;
  RegistryKey software = hkml.OpenSubKey("SOFTWARE\\test");
  //RegistryKey software = hkml.OpenSubKey("SOFTWARE\\test", true);
  subkeyNames = software.GetValueNames();
  //取得该项下所有键值的名称的序列，并传递给预定的数组中
  foreach (string keyName  in subkeyNames)
  {
    if (keyName ==  "test") //判断键值的名称
    {
        hkml.Close();
        return true;
    }    
    
  }
  hkml.Close();
  return false;
}