string strProject = "Exec";
string p_FileTypeName =".cdb";//文件后缀
string fileName = System.Windows.Forms.Application.ExecutablePath;// 获取启动了应用程序的可执行文件的路径及文件名
//string startPath = System.Windows.Forms.Application.StartupPath;//获取启动了应用程序的可执行文件的路径
//注册文件类型
Registry.ClassesRoot.CreateSubKey(p_FileTypeName).SetValue("", strProject, RegistryValueKind.String);
using (RegistryKey key = Registry.ClassesRoot.CreateSubKey(strProject))
{
//设置图标
RegistryKey iconKey = key.CreateSubKey("DefaultIcon");
iconKey.SetValue("", System.Windows.Forms.Application.StartupPath + "\ooopic_1564036072.ico");
//设置默认启动程序
key.CreateSubKey(@"ShellOpenCommand").SetValue("", fileName + " "%1"", RegistryValueKind.ExpandString);
}