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I want to read all pages of my PDF and save them as a images, so far what I am doing is only getting me the page defined 0 = 1 first etc .. Is there a chance that I can define a range ?
static void Main(string[] args)
{
try
{
string path = #"C:\Users\test\Desktop\pdfToWord\";
foreach (string file in Directory.EnumerateFiles(path, "*.pdf")) {
using (var document = PdfiumViewer.PdfDocument.Load(file))
{
int i = 1;
var image = document.Render(0,300,300, true);
image.Save(#"C:\Users\test\Desktop\pdfToWord\output.png", ImageFormat.Png);
}
}
}
catch (Exception ex)
{
// handle exception here;
}
if your document-object gives you the pagecount,
you could replace
int i = 1;
var image = document.Render(0,300,300, true);
image.Save(#"C:\Users\test\Desktop\pdfToWord\output.png", ImageFormat.Png);
by
for(int index = 0; index < document.PageCount; index++)
{
var image = document.Render(index,300,300, true);
image.Save(#"C:\Users\test\Desktop\pdfToWord\output"+index.ToString("000")+".png", ImageFormat.Png);
}
I need to parse this string from serial:-
!00037,00055#
00037 as one string, 00055 as another string
However this string is came out when the robot's tire is rotated and some other string may also display before and after the string that I need to parse. For example this is the some of the transmission received:-
11,00085#R-STOPR-STOP!00011,00095#!00001,00015#R-STOP!00001,00085#!00003,00075#!00006,00015#R-STOP!00009,00025#!00011,00035#!00011,00085#R-STOPR-STOP!00011,00095#!00001,00015#R-STOP!00001,00085#!00003,00075#!00006,00015#R-STOP!00009,00025#!00011,00035#R-STOP!00001,00085#!00003,00075#!00006,00015#R-STOP!00009,00025#!00011,00035#R-STOP!00037,00055#!00023,00075#R-STOPR-STOP!00022,00065#!00011,00085#R-STOPR-STOP!00011,00095#!00001,00015#R-STOP!00001,00085#!00003,00075#!00006,00015#R-STOP!00009,00025#!00011,00035#R-STOP!00037,00055#!00023,00075#R-STOPR-STOP!00022,00065#!00011,00085#R-STOPR-STOP!00011,00095#!00001,00015#
So far I'm stuck at what to do next after SerialPort.ReadExisting()
Here is some code to retrieve the serial data:-
private void serialCom_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
try
{
InputData = serialCom.ReadExisting();
if (InputData != String.Empty)
{
this.BeginInvoke(new SetTextCallback(IncomingData), new object[] { InputData });
}
}
catch
{
MessageBox.Show("Error");
}
}
and display incoming serial data inside textbox
private void IncomingData(string data)
{
tb_incomingData.AppendText(data);
tb_incomingData.ScrollToCaret();
}
This code is using .NET Framework 4.0 and Windows Form.
Finally solve it using indexof and substring.
private void IncomingData(string data)
{
//Show received data in textbox
tb_incomingData.AppendText(data);
tb_incomingData.ScrollToCaret();
//Append data inside longdata (string)
longData = longData + data;
if (longData.Contains('#') && longData.Contains(',') && longData.Contains('!'))
{
try
{
indexSeru = longData.IndexOf('!'); //retrieve index number of the symbol !
indexComma = longData.IndexOf(','); //retrieve index number of the symbol ,
indexAlias = longData.IndexOf('#'); //retrieve index number of the symbol ,
rotation = longData.Substring(indexSeru + 1, 5); //first string is taken after symbol ! and 5 next char
subRotation = longData.Substring(indexComma + 1, 5); //second string is taken after symbol ! and 5 next char
//tss_distance.Text = rotation + "," + subRotation;
longData = null; //clear longdata string
}
catch
{
indexSeru = 0;
indexComma = 0;
indexAlias = 0;
}
}
}
You can determine your pattern to transform this string into a array using SPLIT function.
This code, send "!00037,00055#" returns two itens: 00037 and 00055.
static void Main(string[] args)
{
string k = "!00037,00055#";
var array = k.ToString().Split(',');
Console.WriteLine("Dirty Itens");
for (var x = 0; x <= array.Length - 1; x++)
{
var linha = "Item " + x.ToString() + " = " + array[x];
Console.WriteLine(linha);
}
Console.WriteLine("Cleaned Itens");
for (var x = 0; x <= array.Length - 1; x++)
{
var linha = "Item " + x.ToString() + " = " + CleanString(array[x]);
Console.WriteLine(linha);
}
Console.ReadLine();
}
public static string CleanString(string inputString)
{
string resultString = "";
Regex regexObj = new Regex(#"[^\d]");
resultString = regexObj.Replace(inputString, "");
return resultString;
}
I am developing a WPF application.
In this application I read from multiple txt files using Taks(thread) and display them.
Sometimes I get an exception
Destination array is not long enough to copy all the items in the collection. Check array index and length.
And in detail I can read:
C:\Windows\mscorlib.pdb: Cannot find or open the PDB file.
And:
A first chance exception of type 'System.ArgumentException' occurred in mscorlib.dll
I have no Idea were to start debugging and there is no pattern over this weird exception.
UPDATE: The code for reading txt file:
public void LoadCompassLogFile(String fileName) {
//Thread.CurrentThread.Priority = ThreadPriority.Highest;
if (!fileName.Contains("Compass")) {
throw new FileLoadException("Wrong File");
}
CompassLogLoadCompleted = false;
CompassLogLoadPercent = 0;
_compassLogCollection.Clear();
int numberOfSingleLineLog = 0;
String[] lines = new string[] {};
String temp = "";
DateTime dateTime = new DateTime();
LoggingLvl loggingLvl = new LoggingLvl();
LoggingLvl.ELoggingLvl eLoggingLvl = new LoggingLvl.ELoggingLvl();
char[] delimiters = new[] {' '};
string threadId = "";
string loggingMessage = "";
int ff = 0;
// Read the File and add it to lines string
try {
lines = File.ReadAllLines(fileName);
} catch (Exception e) {
CompassLogLoadCompleted = true;
CoreServiceLogLoadCompleted = true;
Console.WriteLine("The file could not be read:");
Console.WriteLine(e.Message);
}
string[] parts;
for (int j = 0; j < lines.Count(); j++) {
string dateAndTimestamp = "";
if (!CompassLogLoadCompleted) {
try {
lock (_myLock) {
parts = lines[j].Split(delimiters,
StringSplitOptions.
RemoveEmptyEntries);
}
numberOfSingleLineLog++;
foreach (string t in parts) {
switch (ff) {
case 0:
dateAndTimestamp = t;
break;
case 1:
dateAndTimestamp += " " + t.Replace(",", ".");
dateTime = DateTime.Parse(dateAndTimestamp);
dateAndTimestamp = "";
break;
case 2:
eLoggingLvl = loggingLvl.ParseLoggingLvl(t);
break;
case 3:
threadId = t;
break;
default:
temp += t;
break;
}
ff++;
}
loggingMessage = temp;
temp = "";
ff = 0;
loggingLvl = new LoggingLvl(eLoggingLvl);
CompassLogData cLD = new CompassLogData(
numberOfSingleLineLog,
dateTime,
loggingLvl, threadId,
loggingMessage);
_compassLogCollection.Add(cLD);
//loggingMessage = "";
} catch (Exception ex) {
Console.Out.WriteLine("Shit Happens");
Console.Out.WriteLine(ex.StackTrace);
}
CompassLogLoadPercent = ((double) j
/lines.Count())*100;
}
}
CompassLogLoadCompleted = true;
Console.Out.WriteLine("Compass LOADING DONE");
Console.Out.WriteLine("numberOfSingleLineLog: " +
numberOfSingleLineLog);
Console.Out.WriteLine("");
}
I think the lenght of an array is max 2GB in .net so depending on what type you are putting in it you need to divide (2^31)/8 for a long[] and for a byte i think its (2^31)/4 so thats around 500 MB. Are your files larger than that?
On your second problem that it cannot find th PDB go to Tools --> Options --> Debugging --> Symbols and select Microsoft Symbol Servers this can fix the problem.
If you have enough information this can fix your last problem also...
Hi all i am having a list box on my Form which will display all the .txt files from the directory C:. This list box selection mode is set to MultiExtended.
My condition to check whether the file is valid or not will be checked using the condition as each and every line content of the selected file should be *94*. If this one satisifes then only it is said to be a valid file. I have written a code for this too but as i am checking in the loop and at a time i can only read one file content this was working fine. But i have to check initially all the selected files matches the condition or not if ok then i have to do the remaining code if not i would like to display error
My code on Button Click
private void btnMerge_Click(object sender, EventArgs e)
{
if (lstACH.SelectedIndices.Count == 1)
{
MessageBox.Show("Select 2 Files To Merge");
}
else
{
for (i = 0; i < lstACH.SelectedItems.Count; i++)
{
strFile = lstACH.SelectedItems[i].ToString();
lines = File.ReadAllLines(strFile);
if (LinesHaveCorrectLength(lines, 94)) // Here i am checking but at a tym i am checking one file only i have to check for all and if ok then the remaining code has to be executed
{
if (i == 0)
{
Stream myStream;
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.InitialDirectory = #"C:\";
saveFileDialog1.DefaultExt = "txt";
saveFileDialog1.Filter = "(*.txt)|*.txt";
saveFileDialog1.FilterIndex = 2;
saveFileDialog1.RestoreDirectory = true;
saveFileDialog1.ValidateNames = true;
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
Append.FileName = saveFileDialog1.FileName;
if (Append.FileName.Contains(" \\/:*?<>|"))
{
MessageBox.Show("File name should not contain \\/:*?<>|", "", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
else
{
if ((myStream = saveFileDialog1.OpenFile()) != null)
{
Append.FileName = saveFileDialog1.FileName;
myStream.Close();
}
}
}
}
using (StreamWriter sw = new StreamWriter(Append.FileName, true))
{
using (StreamReader srBatch = new StreamReader(strFile))
{
while (srBatch.Peek() >= 0)
{
strReadLine = srBatch.ReadLine();
if (strReadLine.StartsWith("1"))
{
if (i == 0)
{
strFileHeader = strReadLine;
sw.WriteLine(strFileHeader);
}
}
if (strReadLine.StartsWith("5"))
{
strBtchHeader = strReadLine;
if (i == 0)
{
Btchno = Convert.ToInt32(strReadLine.Substring(87, 7));
BatchCnt = Convert.ToInt16(Btchno);
}
if (i > 0)
{
BatchCnt++;
strBtchHeader = strBtchHeader.Substring(0, 87) + Convert.ToString(BatchCnt.ToString().PadLeft(7, (char)48));
}
sw.WriteLine(strBtchHeader);
}
if (strReadLine.StartsWith("6"))
{
strEntryDetail = strReadLine;
if (i == 0)
{
strTraceNo = strEntryDetail.Substring(87, 7);
EntryCount = Convert.ToInt16(strTraceNo);
}
if (i > 0)
{
EntryCount++;
strEntryDetail = strEntryDetail.Substring(0, 87) + EntryCount.ToString().PadLeft(7, (char)48);
}
sw.WriteLine(strEntryDetail);
}
if (strReadLine.StartsWith("8"))
{
strBtchCntrl = strReadLine;
if (i > 0)
{
//btchEntry++;
strBtchCntrl = strBtchCntrl.Substring(0, 87) + BatchCnt.ToString().PadLeft(7, (char)48);
}
sw.WriteLine(strBtchCntrl);
}
if (strReadLine.StartsWith("9"))
{
strFileCntrl = strReadLine;
strBtchCnt = strReadLine.Substring(1, 6);
strEntrycnt = strReadLine.Substring(13, 8);
strEntryHash = strReadLine.Substring(21, 10);
strDebitAmnt = strReadLine.Substring(31, 12);
strCreditAmnt = strReadLine.Substring(43, 12);
BtchCnt += Convert.ToDouble(strBtchCnt);
Entrycnt += Convert.ToDouble(strEntrycnt);
EntryHash += Convert.ToDouble(strEntryHash);
DebitAmnt += Convert.ToDouble(strDebitAmnt);
CreditAmnt += Convert.ToDouble(strCreditAmnt);
if (i == lstACH.SelectedItems.Count - 1)
{
strFileCntrl = strFileCntrl.Substring(0, 1) + BtchCnt.ToString().PadLeft(6, (char)48) + strFileCntrl.Substring(7, (strFileCntrl.Length - 7));
strFileCntrl = strFileCntrl.Substring(0, 13) + Entrycnt.ToString().PadLeft(8, (char)48) + strFileCntrl.Substring(21, (strFileCntrl.Length - 21));
strFileCntrl = strFileCntrl.Substring(0, 21) + EntryHash.ToString().PadLeft(10, (char)48) + strFileCntrl.Substring(31, (strFileCntrl.Length - 31));
strFileCntrl = strFileCntrl.Substring(0, 31) + DebitAmnt.ToString().PadLeft(12, (char)48) + strFileCntrl.Substring(43, (strFileCntrl.Length - 43));
strFileCntrl = strFileCntrl.Substring(0, 43) + CreditAmnt.ToString().PadLeft(12, (char)48) + strFileCntrl.Substring(55, (strFileCntrl.Length - 55));
sw.WriteLine(strFileCntrl);
}
}
}
}
}
if (i == lstACH.SelectedItems.Count - 1)
{
MessageBox.Show("File Has Been Merged Successfully");
this.Close();
}
}
else
{
MessageBox.Show("One of the Selected File is not a Valid ACH File");
break;
}
}
}
}
Checking for Each and every line Length
private static bool LinesHaveCorrectLength(string[] lines, int expectedLineLength)
{
foreach (string item in lines)
{
if (item.Length != expectedLineLength)
{
return false;
}
}
return true;
}
Just check them all first - and if all good, THEN begin merge.
if (lstACH.SelectedIndices.Count != 2)
{
MessageBox.Show("Select 2 Files To Merge");
return;
}
foreach (String fileName in lstACH.SelectedItems)
{
if( LinesHaveCorrectLength( File.ReadAllLines(fileName), 94 ) == false )
{
MessageBox.Show("File: " + fileName + " has an incorrect line length");
return;
}
}
// Now process them all again to merge:
foreach(String fileName in lstACH.SelectedItems)
{
// ... do merge logic
}
Ok according to your comment it looks like First you want both files to be validated. if that is the case then:
(There could be many ways , this is one of them)
First define a Function to do the checking for all files:
public bool AreFilesValid(ListBox.SelectedObjectCollection filenames)
{
int count = filenames.Count;
bool valid = false;
for(int i=0;i<count;i++)
{
string strFile = filenames[i].ToString();
string[] lines = File.ReadAllLines(strFile);
if(LinesHaveCorrectLength(lines, 94)) { valid=true; }
else { valid = false; }
}
return valid;
}
Then call it in your if condition, i.e just change following lines:
...
strFile = lstACH.SelectedItems[i].ToString();
lines = File.ReadAllLines(strFile);
if (LinesHaveCorrectLength(lines, 94))
{
...
To only this:
...
if (AreFilesValid(lstACH.SelectedItems))
{
...
You have already got your else statement down the code to catch when this if condition fails.
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Is there any built in method in the .NET library that will return all of the MX records for a given domain? I see how you get CNAMES, but not MX records.
Update 2018/5/23:
Check out MichaC's answer for a newer library that has .NET standard support.
Original Answer:
The ARSoft.Tools.Net library by Alexander Reinert seems to do the job pretty well.
It's available from NuGet:
PM> Install-Package ARSoft.Tools.Net
Import the namespace:
using ARSoft.Tools.Net.Dns;
Then making a synchronous lookup is as simple as:
var resolver = new DnsStubResolver();
var records = resolver.Resolve<MxRecord>("gmail.com", RecordType.Mx);
foreach (var record in records) {
Console.WriteLine(record.ExchangeDomainName?.ToString());
}
Which gives us the output:
gmail-smtp-in.l.google.com.
alt1.gmail-smtp-in.l.google.com.
alt2.gmail-smtp-in.l.google.com.
alt3.gmail-smtp-in.l.google.com.
alt4.gmail-smtp-in.l.google.com.
Underneath the hood, it looks like the library constructs the UDP (or TCP) packets necessary to send to the resolver, like you might expect. The library even has logic (invoked with DnsClient.Default) to discover which DNS server to query.
Full documentation can be found here.
Just roled my own library because there was nothing for .net core / xplat support... https://github.com/MichaCo/DnsClient.NET
It works pretty great and gives you dig like log messages if you want.
Simple to use
var lookup = new LookupClient();
var result = await lookup.QueryAsync("google.com", QueryType.ANY);
and works with custom servers running on any ports, multiple servers, etc...
see also DnsClient Website for more details
I spent all day figuring out how to send/receive dns requests and came up with this. Its a complete generic handler. You just have to set the dns server and pass in 'd' eg. my.website.com?d=itmanx.com
<%# WebHandler Language="C#" Class="Handler" %>
using System;
using System.Web;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Collections.Generic;
public class Handler : IHttpHandler
{
string dns = "dc1"; //change to your dns
string qtype = "15"; //A=1 MX=15
string domain = "";
int[] resp;
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
try
{
if (context.Request["t"] != null) qtype = context.Request["t"];
if (context.Request["d"] != null) domain = context.Request["d"];
if (string.IsNullOrEmpty(domain)) throw new Exception("Add ?d=<domain name> to url or post data");
Do(context);
}
catch (Exception ex)
{
string msg = ex.Message;
if (msg == "1") msg = "Malformed packet";
else if (msg == "5") msg = "Refused";
else if (msg == "131") msg = "No such name";
context.Response.Write("Error: " + msg);
}
}
public void Do(HttpContext context)
{
UdpClient udpc = new UdpClient(dns, 53);
// SEND REQUEST--------------------
List<byte> list = new List<byte>();
list.AddRange(new byte[] { 88, 89, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0 });
string[] tmp = domain.Split('.');
foreach (string s in tmp)
{
list.Add(Convert.ToByte(s.Length));
char[] chars = s.ToCharArray();
foreach (char c in chars)
list.Add(Convert.ToByte(Convert.ToInt32(c)));
}
list.AddRange(new byte[] { 0, 0, Convert.ToByte(qtype), 0, 1 });
byte[] req = new byte[list.Count];
for (int i = 0; i < list.Count; i++) { req[i] = list[i]; }
udpc.Send(req, req.Length);
// RECEIVE RESPONSE--------------
IPEndPoint ep = null;
byte[] recv = udpc.Receive(ref ep);
udpc.Close();
resp = new int[recv.Length];
for (int i = 0; i < resp.Length; i++)
resp[i] = Convert.ToInt32(recv[i]);
int status = resp[3];
if (status != 128) throw new Exception(string.Format("{0}", status));
int answers = resp[7];
if (answers == 0) throw new Exception("No results");
int pos = domain.Length + 18;
if (qtype == "15") // MX record
{
while (answers > 0)
{
int preference = resp[pos + 13];
pos += 14; //offset
string str = GetMXRecord(pos, out pos);
context.Response.Write(string.Format("{0}: {1}\n", preference, str));
answers--;
}
}
else if (qtype == "1") // A record
{
while (answers > 0)
{
pos += 11; //offset
string str = GetARecord(ref pos);
context.Response.Write(string.Format("{0}\n", str));
answers--;
}
}
}
//------------------------------------------------------
private string GetARecord(ref int start)
{
StringBuilder sb = new StringBuilder();
int len = resp[start];
for (int i = start; i < start + len; i++)
{
if (sb.Length > 0) sb.Append(".");
sb.Append(resp[i + 1]);
}
start += len + 1;
return sb.ToString();
}
private string GetMXRecord(int start, out int pos)
{
StringBuilder sb = new StringBuilder();
int len = resp[start];
while (len > 0)
{
if (len != 192)
{
if (sb.Length > 0) sb.Append(".");
for (int i = start; i < start + len; i++)
sb.Append(Convert.ToChar(resp[i + 1]));
start += len + 1;
len = resp[start];
}
if (len == 192)
{
int newpos = resp[start + 1];
if (sb.Length > 0) sb.Append(".");
sb.Append(GetMXRecord(newpos, out newpos));
start++;
break;
}
}
pos = start + 1;
return sb.ToString();
}
//------------------------------------------------------
public bool IsReusable { get { return false; } }
}
My approach was to use nslookup.exe to retreive the MX record.
The solution is not as fancy as rewriting whole DNS or using a System DLL -> but it works, with a little amount of lines.
To get things right, this code >just works< it's not ressource efficient nor fast and has a lots of room for improvment (multiple hostnames, async, more usefull return value,adding the priority):
static List<string> GetMxRecords(string host){
ProcessStartInfo nslookup_config = new ProcessStartInfo("nslookup.exe");
nslookup_config.RedirectStandardInput = true;
nslookup_config.RedirectStandardOutput = true;
nslookup_config.RedirectStandardError = true;
nslookup_config.UseShellExecute = false;
var nslookup = Process.Start(nslookup_config);
nslookup.StandardInput.WriteLine("set q=mx");
nslookup.StandardInput.WriteLine(host);
nslookup.StandardInput.WriteLine("exit");
List<string> lines = new List<string>();
while (!nslookup.StandardOutput.EndOfStream)
{
string l = nslookup.StandardOutput.ReadLine();
if (l.Contains("internet address ="))
{
while (l.Contains("\t\t"))
{
l = l.Replace("\t\t", "\t");
}
lines.Add(l.Replace("\tinternet address = ","="));
}
}
nslookup.Close();
return lines;
}
Should be working international, since nslookup does not support any translation (I'm working on a German machine and I'm getting english output).
The result are strings like this:
alt4.gmail-smtp-in.l.google.com=74.125.28.27
alt2.gmail-smtp-in.l.google.com=74.125.200.27
alt1.gmail-smtp-in.l.google.com=209.85.233.26
gmail-smtp-in.l.google.com=66.102.1.27
alt3.gmail-smtp-in.l.google.com=108.177.97.27
The accepted answer doesn't work for .NET framework < 4.5, so would suggest that those of you who can't use ARSOFT.Tools can use DNDNs from https://dndns.codeplex.com
Given below is a console application that returns the MX record for a given domain modifying their examples.
using System;
using System.Net.Sockets;
using DnDns.Enums;
using DnDns.Query;
using DnDns.Records;
namespace DnDnsExamples
{
class Program
{
static void Main(string[] args)
{
DnsQueryRequest request3 = new DnsQueryRequest();
DnsQueryResponse response3 = request3.Resolve("gmail.com", NsType.MX, NsClass.INET, ProtocolType.Tcp);
OutputResults(response3);
Console.ReadLine();
}
private static void OutputResults(DnsQueryResponse response)
{
foreach (IDnsRecord record in response.Answers)
{
Console.WriteLine(record.Answer);
Console.WriteLine(" |--- RDATA Field Length: " + record.DnsHeader.DataLength);
Console.WriteLine(" |--- Name: " + record.DnsHeader.Name);
Console.WriteLine(" |--- NS Class: " + record.DnsHeader.NsClass);
Console.WriteLine(" |--- NS Type: " + record.DnsHeader.NsType);
Console.WriteLine(" |--- TTL: " + record.DnsHeader.TimeToLive);
Console.WriteLine();
}
}
}
}
Here is a Class I use to look up MX records only.
using System;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Collections.Specialized;
namespace Mx.Dns
{
public class Query
{
//Build a DNS query buffer according to RFC 1035 4.1.1 e 4.1.2
private readonly int id;
private readonly int flags;
private readonly int QDcount;
private readonly int ANcount;
private readonly int NScount;
private readonly int ARcount;
private readonly string Qname;
private readonly int Qtype;
private readonly int Qclass;
public byte[] buf;
public Query(int ID, string query, int qtype)
{
//init vectors with given + default values
id = ID;
flags = 256;
QDcount = 1;
ANcount = 0;
NScount = 0;
ARcount = 0;
Qname = query;
Qtype = qtype;
Qclass = 1; //Internet = IN = 1
//build a buffer with formatted query data
//header information (16 bit padding
buf = new byte[12 + Qname.Length + 2 + 4];
buf[0] = (byte)(id / 256);
buf[1] = (byte)(id - (buf[0] * 256));
buf[2] = (byte)(flags / 256);
buf[3] = (byte)(flags - (buf[2] * 256));
buf[4] = (byte)(QDcount / 256);
buf[5] = (byte)(QDcount - (buf[4] * 256));
buf[6] = (byte)(ANcount / 256);
buf[7] = (byte)(ANcount - (buf[6] * 256));
buf[8] = (byte)(NScount / 256);
buf[9] = (byte)(NScount - (buf[8] * 256));
buf[10] = (byte)(ARcount / 256);
buf[11] = (byte)(ARcount - (buf[10] * 256));
//QNAME (RFC 1035 4.1.2)
//no padding
string[] s = Qname.Split('.');
int index = 12;
foreach (string str in s) {
buf[index] = (byte)str.Length;
index++;
byte[] buf1 = Encoding.ASCII.GetBytes(str);
buf1.CopyTo(buf, index);
index += buf1.Length;
}
//add root domain label (chr(0))
buf[index] = 0;
//add Qtype and Qclass (16 bit values)
index = buf.Length - 4;
buf[index] = (byte)(Qtype / 256);
buf[index + 1] = (byte)(Qtype - (buf[index] * 256));
buf[index + 2] = (byte)(Qclass / 256);
buf[index + 3] = (byte)(Qclass - (buf[index + 2] * 256));
}
}
public class C_DNSquery
{
public StringCollection result = new StringCollection();
public int Error = 0;
public string ErrorTxt = "undefined text";
public bool Done = false;
public UdpClient udpClient;
private string DNS;
private string Query;
private int Qtype;
public bool IS_BLACKLIST_QUERY = false;
public C_DNSquery(string IPorDNSname, string query, int type)
{
DNS = IPorDNSname;
Query = query;
Qtype = type;
}
public void doTheJob()
{
//check if provided DNS contains an IP address or a name
IPAddress ipDNS;
IPHostEntry he;
try {
//try to parse an IPaddress
ipDNS = IPAddress.Parse(DNS);
} catch (FormatException ) {
// Console.WriteLine(e);
//format error, probably is a FQname, try to resolve it
try {
//try to resolve the hostname
he = Dns.GetHostEntry(DNS);
} catch {
//Error, invalid server name or address
Error = 98;
ErrorTxt = "Invalid server name:" + DNS;
Done = true;
return;
}
//OK, get the first server address
ipDNS = he.AddressList[0];
}
//Query the DNS server
//our current thread ID is used to match the reply with this process
Query myQuery = new Query(System.Threading.Thread.CurrentThread.ManagedThreadId, Query, Qtype);
//data buffer for query return value
Byte[] recBuf;
//use UDP protocol to connect
udpClient = new UdpClient();
do {
try {
//connect to given nameserver, port 53 (DNS)
udpClient.Connect(DNS, 53);
//send query
udpClient.Send(myQuery.buf, myQuery.buf.Length);
//IPEndPoint object allow us to read datagrams..
//..selecting only packet coming from our nameserver and port
IPEndPoint RemoteIpEndPoint = new IPEndPoint(ipDNS, 53);
//Blocks until a message returns on this socket from a remote host.
recBuf = udpClient.Receive(ref RemoteIpEndPoint);
udpClient.Close();
} catch (Exception e) {
//connection error, probably a wrong server address
udpClient.Close();
Error = 99;
ErrorTxt = e.Message + "(server:" + DNS + ")";
Done = true;
return;
}
//repeat until we get the reply with our threadID
} while (System.Threading.Thread.CurrentThread.ManagedThreadId != ((recBuf[0] * 256) + recBuf[1]));
//Check the DNS reply
//check if bit QR (Query response) is set
if (recBuf[2] < 128) {
//response byte not set (probably a malformed packet)
Error = 2;
ErrorTxt = "Query response bit not set";
Done = true;
return;
}
//check if RCODE field is 0
if ((recBuf[3] & 15) > 0) {
//DNS server error, invalid reply
switch (recBuf[3] & 15) {
case 1:
Error = 31;
ErrorTxt = "Format error. The nameserver was unable to interpret the query";
break;
case 2:
Error = 32;
ErrorTxt = "Server failure. The nameserver was unable to process the query.";
break;
case 3:
Error = 33;
ErrorTxt = "Name error. Check provided domain name!!";
break;
case 4:
Error = 34;
ErrorTxt = "Not implemented. The name server does not support the requested query";
break;
case 5:
Error = 35;
ErrorTxt = "Refused. The name server refuses to reply for policy reasons";
break;
default:
Error = 36;
ErrorTxt = "Unknown. The name server error code was: " + Convert.ToString((recBuf[3] & 15));
break;
}
Done = true;
return;
}
//OK, now we should have valid header fields
int QDcnt, ANcnt, NScnt, ARcnt;
int index;
QDcnt = (recBuf[4] * 256) + recBuf[5];
ANcnt = (recBuf[6] * 256) + recBuf[7];
NScnt = (recBuf[8] * 256) + recBuf[9];
ARcnt = (recBuf[10] * 256) + recBuf[11];
index = 12;
//sometimes there are no erros but blank reply... ANcnt == 0...
if (ANcnt == 0) { // if blackhole list query, means no spammer !!//if ((ANcnt == 0) & (IS_BLACKLIST_QUERY == false))
//error blank reply, return an empty array
Error = 4;
ErrorTxt = "Empty string array";
Done = true;
return;
}
//Decode received information
string s1;
// START TEST
s1 = Encoding.ASCII.GetString(recBuf, 0, recBuf.Length);
// END TEST
if (QDcnt > 0) {
//we are not really interested to this string, just parse and skip
s1 = "";
index = parseString(recBuf, index, out s1);
index += 4; //skip root domain, Qtype and QClass values... unuseful in this contest
}
if (IS_BLACKLIST_QUERY) {
// get the answers, normally one !
// int the four last bytes there is the ip address
Error = 0;
int Last_Position = recBuf.Length - 1;
result.Add(recBuf[Last_Position - 3].ToString() + "." + recBuf[Last_Position - 2].ToString() + "." + recBuf[Last_Position - 1].ToString() + "." + recBuf[Last_Position].ToString());
Done = true;
return;
}
int count = 0;
//get all answers
while (count < ANcnt) {
s1 = "";
index = parseString(recBuf, index, out s1);
//Qtype
int QType = (recBuf[index] * 256) + recBuf[index + 1];
index += 2;
s1 += "," + QType.ToString();
//QClass
int QClass = (recBuf[index] * 256) + recBuf[index + 1];
index += 2;
s1 += "," + QClass.ToString();
//TTL (Time to live)
uint TTL = (recBuf[index] * 16777216u) + (recBuf[index + 1] * 65536u) + (recBuf[index + 2] * 256u) + recBuf[index + 3];
index += 4;
s1 += "," + TTL.ToString();
int blocklen = (recBuf[index] * 256) + recBuf[index + 1];
index += 2;
if (QType == 15) {
int MXprio = (recBuf[index] * 256) + recBuf[index + 1];
index += 2;
s1 += "," + MXprio.ToString();
}
string s2;
index = parseString(recBuf, index, out s2);
s1 += "," + s2;
result.Add(s1);
count++;
}
Error = 0;
Done = true;
}
private int parseString(byte[] buf, int i, out string s)
{
int len;
s = "";
bool end = false;
while (!end) {
if (buf[i] == 192) {
//next byte is a pointer to the string, get it..
i++;
s += getString(buf, buf[i]);
i++;
end = true;
} else {
//next byte is the string length
len = buf[i];
i++;
//get the string
s += Encoding.ASCII.GetString(buf, i, len);
i += len;
//check for the null terminator
if (buf[i] != 0) {
//not null, add a point to the name
s += ".";
} else {
//null char..the string is complete, exit
end = true;
i++;
}
}
}
return i;
}
private string getString(byte[] buf, int i)
{
string s = "";
int len;
bool end = false;
while (!end) {
len = buf[i];
i++;
s += Encoding.ASCII.GetString(buf, i, len);
i += len;
if (buf[i] == 192) {
i++;
s += "." + getString(buf, buf[i]);
return s;
}
if (buf[i] != 0) {
s += ".";
} else {
end = true;
}
}
return s;
}
}
}
Here is how you use it.
/// <summary>
/// Get the MX from the domain address.
/// </summary>
public static string getMXrecord(string domain)
{
domain = domain.Substring(domain.IndexOf('#') + 1);
string LocalDNS = GetDnsAdress().ToString();
Console.WriteLine("domain: " + domain);
// resolv the authoritative domain (type=2)
C_DNSquery DnsQry = new C_DNSquery(LocalDNS, domain, 2);
Thread t1 = new Thread(new ThreadStart(DnsQry.doTheJob));
t1.Start();
int timeout = 20;
while ((timeout > 0) & (!DnsQry.Done)) {
Thread.Sleep(100);
timeout--;
}
if (timeout == 0) {
if (DnsQry.udpClient != null) {
DnsQry.udpClient.Close();
}
t1.Abort();
DnsQry.Error = 100;
}
string[] ns1;
string MyNs = "";
if (DnsQry.Error == 0) {
ns1 = DnsQry.result[0].Split(',');
MyNs = ns1[4];
t1.Abort();
} else {
t1.Abort();
MyNs = LocalDNS;
}
// Resolve MX (type = 15)
DnsQry = new C_DNSquery(MyNs, domain, 15);
Thread t2 = new Thread(new ThreadStart(DnsQry.doTheJob));
t2.Start();
timeout = 20;
string TTL = "";
string MXName = "";
Int32 preference = 9910000;
while ((timeout > 0) & (!DnsQry.Done)) {
Thread.Sleep(100);
timeout--;
}
if (timeout == 0) {
if (DnsQry.udpClient != null) {
DnsQry.udpClient.Close();
}
t2.Abort();
DnsQry.Error = 100;
}
if (DnsQry.Error == 0) {
if (DnsQry.result.Count == 1) {
string[] ns2 = DnsQry.result[0].Split(',');
MXName = ns2[5];
TTL = ns2[3];
preference = Int32.Parse(ns2[4]);
Console.WriteLine("domaine: {0} MX: {1} time: {2} pref: {3} ttl: {4}", domain.Substring(domain.IndexOf('#') + 1), MXName,
DateTime.Now, preference, TTL);
} else {
for (int indns = 0; indns <= DnsQry.result.Count - 1; indns++) {
string[] ns2 = DnsQry.result[indns].Split(',');
if (Int32.Parse(ns2[4]) < preference) {
MXName = ns2[5];
TTL = ns2[3];
preference = Int32.Parse(ns2[4]);
Console.WriteLine("domain: {0} MX: {1} time: {2} pref: {3} ttl: {4}", domain.Substring(domain.IndexOf('#') + 1), MXName,
DateTime.Now, preference, TTL);
}
}
}
}
return MXName;
}
I wrote a simply URL for that means
https://devselz.com/social/sign/buttons/dashboard/default.aspx?a=ciee&email=emailaddresstocheckifexistsornot#anydomain.com
Do not abuse
Return 1 if email exists or may exist, 0 if not
Works great in order to check:
gmail and gmail pro (domains not #gmail) accounts.
hotmail
For others like yahoo always returns 1
You can use this open source library to do almost any kind of query you would usually need.
Usage:
DnsClient dnsClient = new DnsClient();
string mxDomain = dnsClient.ResolveMX("example.com");
string mxDomainIP = dnsClient.ResolveMX("example.com", true);
string mxDomainIPv6 = dnsClient.ResolveMX("example.com", true, true);