Export PFX and CER certificates from a self-signed certificate

Full code:

public sealed class Datacertificate {#region Generate a certificate///<summary>//According to the specified certificate title and Makecer   
        T full path Generation certificate (contains public and private keys and saved in my store)///</summary>//<param name= "Subjectname" ></param> <param name= "Makecertpath" ></param>//<returns></returns> P Ublic static bool Createcertwithprivatekey (string subjectname, String makecertpath) {subjectname = "C
            n= "+ subjectname;
            string param = "-pe-ss my-n \" "+ Subjectname +" \ ";
                try {Process p = process.start (Makecertpath, param);
                p.WaitForExit ();
            P.close ();
            } catch (Exception e) {return false;
        } return true; #endregion #region File Import/export///<summary>////from the personal my area of the Windows certificate store to find the topic Subjectnam   
 E's certificate,       and export to a PFX file, assign it a password at the same time///and remove the certificate from the personal area (if Isdelfromstor is true)///</summary> <param name= "Subjectname" > Certificate subject, not including cn=</param>//<param name= "pfxfilename" >pfx file name </p aram>//<param name= "password" >pfx file password </param>///<param Name= "Isdelfromstore" & gt; Whether to remove from storage </param>///<returns></returns> public static bool Exporttopfxfile (str  ing subjectname, string pfxfilename, string password, bool isdelfromstore) {subjectname =
            "cn=" + subjectname;
            X509store store = new X509store (storename.my, Storelocation.currentuser); Store.
            Open (Openflags.readwrite); X509Certificate2Collection storecollection = (x509certificate2collection) store.
            certificates; foreach (X509Certificate2 x509 in storecollection) {if (x509.
      Subject = = subjectname)          {Debug.Print (String. Format ("certificate name: {0}", X509.

                    Subject)); byte[] Pfxbyte = x509.
                    Export (x509contenttype.pfx, password);
                        using (FileStream FileStream = new FileStream (Pfxfilename, FileMode.Create)) {   
                        Write the data to the file, and byte by byte.
                        for (int i = 0; i < pfxbyte.length; i++) Filestream.writebyte (Pfxbyte[i]);   
                        Set the stream position to the beginning of the file.
                        Filestream.seek (0, Seekorigin.begin);   
                        Read and verify the data. for (int i = 0; i < filestream.length; i++) {if (pfxbyte[i]! = Fil
                                Estream.readbyte ()) {filestream.close ();
  return false;                          }} filestream.close (); } if (Isdelfromstore = = True) store.
                Remove (X509); }} store.
            Close ();
        return true;   
        }////<summary>//from the personal my area of the Windows certificate store, find the certificate subject to Subjectname,///and export as a CER file (that is, only the public key is included) </summary>//<param name= "subjectname" ></param>//<param name= " Cerfilename "></param>///<returns></returns> public static bool Exporttocerfil
            E (String subjectname, String cerfilename) {subjectname = "cn=" + subjectname;
            X509store store = new X509store (storename.my, Storelocation.currentuser); Store.
            Open (Openflags.readwrite); X509Certificate2Collection storecollection = (x509certificate2collection) store. CertificaTEs foreach (X509Certificate2 x509 in storecollection) {if (x509. Subject = = subjectname) {Debug.Print (String. Format ("certificate name: {0}", X509.
                    Subject)); byte[] Pfxbyte = x509.   
                    Export (x509contenttype.pfx, password); byte[] Cerbyte = x509.
                    Export (X509contenttype.cert);
                        using (FileStream FileStream = new FileStream (Cerfilename, FileMode.Create)) {   
                        Write the data to the file, and byte by byte.
                        for (int i = 0; i < cerbyte.length; i++) Filestream.writebyte (Cerbyte[i]);   
                        Set the stream position to the beginning of the file.
                        Filestream.seek (0, Seekorigin.begin);   
                        Read and verify the data.
            for (int i = 0; i < filestream.length; i++)            {if (cerbyte[i]! = Filestream.readbyte ()) {
                                Filestream.close ();
                            return false;
                    }} filestream.close (); }}} store.
            Close ();
            store = null;
            Storecollection = null;
        return true; #endregion #region Obtain the information from the certificate///<summary>///or the certificate entity according to the private key certificate, the entity can be added according to its public key and private key. Cryptographic///decryption functions use Dencrypt's rsacryption class//</summary>//<param name= "Pfxfilename" & gt;</param>//<param name= "password" ></param>///<returns></returns&gt   
        ;
            public static X509Certificate2 Getcertificatefrompfxfile (string pfxfilename, string password) {
  Try          {return new X509Certificate2 (pfxfilename, password, x509keystorageflags.exportable);
            } catch (Exception e) {return null; }}///<summary>///to the store for certificates///</summary>//<param N Ame= "Subjectname" ></param>///<returns></returns> public static X509certificat
            E2 Getcertificatefromstore (String subjectname) {subjectname = "cn=" + subjectname;
            X509store store = new X509store (storename.my, Storelocation.currentuser); Store.
            Open (Openflags.readwrite); X509Certificate2Collection storecollection = (x509certificate2collection) store.
            certificates; foreach (X509Certificate2 x509 in storecollection) {if (x509.
                Subject = = subjectname) {return x509;
        }    } store.
            Close ();
            store = null;
            Storecollection = null;
        return null; }///<summary>///certificate entities are returned according to the public key certificate///</summary>//<param name= "
            Cerpath "></param> public static X509Certificate2 Getcertfromcerfile (string cerpath) {
            try {return new X509Certificate2 (Cerpath);
            } catch (Exception e) {return null; }} #endregion}