//获取模块的完整路径。
string path1 = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;
//获取和设置当前目录(该进程从中启动的目录)的完全限定目录
string path2 = System.Environment.CurrentDirectory;
//获取应用程序的当前工作目录
string path3 = System.IO.Directory.GetCurrentDirectory();
//获取程序的基目录
string path4 = System.AppDomain.CurrentDomain.BaseDirectory;
//获取和设置包括该应用程序的目录的名称
string path5 = System.AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
//获取启动了应用程序的可执行文件的路径
string path6 = System.Windows.Forms.Application.StartupPath;
//获取启动了应用程序的可执行文件的路径及文件名
string path7 = System.Windows.Forms.Application.ExecutablePath;

string path8 = System.Reflection.Assembly.GetExecutingAssembly().Location;

string path9 = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);

public static string AssemblyDirectory
{
    get
    {
        string codeBase = Assembly.GetExecutingAssembly().CodeBase;
        UriBuilder uri = new UriBuilder(codeBase);
        string path = Uri.UnescapeDataString(uri.Path);
        return Path.GetDirectoryName(path);
    }
}