尝试创建一个 websocket 来控制客户端的打印，并使用 ajax 从页面向 localhost 发送数据。
/// websocket
using System;
using System.Net;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
namespace Server
{
class Program
{
public static WebsocketServer ws;
static void Main(string[] args)
{
ws = new Server.WebsocketServer();
ws.LogMessage += Ws_LogMessage;
ws.Start("http://localhost:2645/service/");
Console.WriteLine("Press any key to exit...");
Console.ReadKey();
}
private static void Ws_LogMessage(object sender, WebsocketServer.LogMessageEventArgs e)
{
Console.WriteLine(e.Message);
}
}
public class WebsocketServer
{
public event OnLogMessage LogMessage;
public delegate void OnLogMessage(Object sender, LogMessageEventArgs e);
public class LogMessageEventArgs : EventArgs
{
public string Message { get; set; }
public LogMessageEventArgs(string Message)
{
this.Message = Message;
}
}
public bool started = false;
public async void Start(string httpListenerPrefix)
{
HttpListener httpListener = new HttpListener();
httpListener.Prefixes.Add(httpListenerPrefix);
httpListener.Start();
LogMessage(this, new LogMessageEventArgs("Listening..."));
started = true;
while (started)
{
HttpListenerContext httpListenerContext = await httpListener.GetContextAsync();
if (httpListenerContext.Request.IsWebSocketRequest)
{
ProcessRequest(httpListenerContext);
}
else
{
httpListenerContext.Response.StatusCode = 400;
httpListenerContext.Response.Close();
LogMessage(this, new LogMessageEventArgs("Closed..."));
}
}
}
public void Stop()
{
started = false;
}
private async void ProcessRequest(HttpListenerContext httpListenerContext)
{
WebSocketContext webSocketContext = null;
try
{
webSocketContext = await httpListenerContext.AcceptWebSocketAsync(subProtocol: null);
LogMessage(this, new LogMessageEventArgs("Connected"));
}
catch (Exception e)
{
httpListenerContext.Response.StatusCode = 500;
httpListenerContext.Response.Close();
LogMessage(this, new LogMessageEventArgs(String.Format("Exception: {0}", e)));
return;
}
WebSocket webSocket = webSocketContext.WebSocket;
try
{
while (webSocket.State == WebSocketState.Open)
{
ArraySegment<Byte> buffer = new ArraySegment<byte>(new Byte[8192]);
WebSocketReceiveResult result = null;
using (var ms = new System.IO.MemoryStream())
{
do
{
result = await webSocket.ReceiveAsync(buffer, CancellationToken.None);
ms.Write(buffer.Array, buffer.Offset, result.Count);
}
while (!result.EndOfMessage);
ms.Seek(0, System.IO.SeekOrigin.Begin);
if (result.MessageType == WebSocketMessageType.Text)
{
using (var reader = new System.IO.StreamReader(ms, Encoding.UTF8))
{
var r = System.Text.Encoding.UTF8.GetString(ms.ToArray());
var t = Newtonsoft.Json.JsonConvert.DeserializeObject<Datos>(r);
bool valid = true;
byte[] toBytes = Encoding.UTF8.GetBytes(""); ;
if (t != null)
{
if (t.printer.Trim() == string.Empty)
{
var printers = "";
foreach (var imp in System.Drawing.Printing.PrinterSettings.InstalledPrinters)
{
printers += imp + "\n";
}
toBytes = Encoding.UTF8.GetBytes("No se Indicó la Impresora\nLas Impresoras disponibles son: " + printers);
valid = false;
}
if (t.name.Trim() == string.Empty)
{
toBytes = Encoding.UTF8.GetBytes("No se Indicó el nombre del Documento");
valid = false;
}
if (t.code == null)
{
toBytes = Encoding.UTF8.GetBytes("No hay datos para enviar a la Impresora");
valid = false;
}
if (valid)
{
print.RawPrinter.SendStringToPrinter(t.printer, t.code, t.name);
toBytes = Encoding.UTF8.GetBytes("Correcto...");
}
await webSocket.SendAsync(new ArraySegment<byte>(toBytes, 0, int.Parse(toBytes.Length.ToString())), WebSocketMessageType.Binary, result.EndOfMessage, CancellationToken.None);
}
else
{
toBytes = Encoding.UTF8.GetBytes("Error...");
await webSocket.SendAsync(new ArraySegment<byte>(toBytes, 0, int.Parse(toBytes.Length.ToString())), WebSocketMessageType.Binary, result.EndOfMessage, CancellationToken.None);
}
}
}
}
}
}
catch (Exception e)
{
LogMessage(this, new LogMessageEventArgs(String.Format("Exception: {0} \nLinea:{1}", e, e.StackTrace)));
}
finally
{
if (webSocket != null)
webSocket.Dispose();
}
}
}
public class Datos
{
public string name { get; set; }
public string code { get; set; }
public string printer { get; set; } = "";
}
}
原始打印：
using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.IO;
namespace print
{
public class RawPrinter
{
// Structure and API declarions:
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public class DOCINFOA
{
[MarshalAs(UnmanagedType.LPStr)]
public string pDocName;
[MarshalAs(UnmanagedType.LPStr)]
public string pOutputFile;
[MarshalAs(UnmanagedType.LPStr)]
public string pDataType;
}
[DllImport("winspool.Drv", EntryPoint = "OpenPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)]
string szPrinter, ref IntPtr hPriknter, IntPtr pd);
[DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool ClosePrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In(), MarshalAs(UnmanagedType.LPStruct)]
DOCINFOA di);
[DllImport("winspool.Drv", EntryPoint = "EndDocPrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool EndDocPrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", EntryPoint = "StartPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool StartPagePrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", EntryPoint = "EndPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool EndPagePrinter(IntPtr hPrinter);
[DllImport("winspool.Drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, ref Int32 dwWritten);
// SendBytesToPrinter()
// When the function is given a printer name and an unmanaged array
// of bytes, the function sends those bytes to the print queue.
// Returns true on success, false on failure.
public static bool SendBytesToPrinter(string szPrinterName, IntPtr pBytes, Int32 dwCount, string DocName = "")
{
Int32 dwError = 0;
Int32 dwWritten = 0;
IntPtr hPrinter = new IntPtr(0);
DOCINFOA di = new DOCINFOA();
bool bSuccess = false;
// Assume failure unless you specifically succeed.
di.pDocName = string.IsNullOrEmpty(DocName) ? "My C#.NET RAW Document" : DocName;
di.pDataType = "RAW";
// Open the printer.
if (OpenPrinter(szPrinterName.Normalize(), ref hPrinter, IntPtr.Zero))
{
// Start a document.
if (StartDocPrinter(hPrinter, 1, di))
{
// Start a page.
if (StartPagePrinter(hPrinter))
{
// Write your bytes.
bSuccess = WritePrinter(hPrinter, pBytes, dwCount, ref dwWritten);
EndPagePrinter(hPrinter);
}
EndDocPrinter(hPrinter);
}
ClosePrinter(hPrinter);
}
// If you did not succeed, GetLastError may give more information
// about why not.
if (bSuccess == false)
{
dwError = Marshal.GetLastWin32Error();
}
return bSuccess;
}
public static bool SendFileToPrinter(string szPrinterName, string szFileName)
{
// Open the file.
FileStream fs = new FileStream(szFileName, FileMode.Open);
// Create a BinaryReader on the file.
BinaryReader br = new BinaryReader(fs);
// Dim an array of bytes big enough to hold the file's contents.
Byte[] bytes = new Byte[fs.Length];
bool bSuccess = false;
// Your unmanaged pointer.
IntPtr pUnmanagedBytes = new IntPtr(0);
int nLength = 0;
nLength = Convert.ToInt32(fs.Length);
// Read the contents of the file into the array.
bytes = br.ReadBytes(nLength);
// Allocate some unmanaged memory for those bytes.
pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
// Copy the managed byte array into the unmanaged array.
Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
// Send the unmanaged bytes to the printer.
bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
// Free the unmanaged memory that you allocated earlier.
Marshal.FreeCoTaskMem(pUnmanagedBytes);
return bSuccess;
}
public static bool SendStringToPrinter(string szPrinterName, string szString, string DocName = "")
{
IntPtr pBytes = default(IntPtr);
Int32 dwCount = default(Int32);
// How many characters are in the string?
dwCount = szString.Length;
// Assume that the printer is expecting ANSI text, and then convert
// the string to ANSI text.
pBytes = Marshal.StringToCoTaskMemAnsi(szString);
// Send the converted ANSI string to the printer.
SendBytesToPrinter(szPrinterName, pBytes, dwCount, DocName);
Marshal.FreeCoTaskMem(pBytes);
return true;
}
}
}
html页面：
<!DOCTYPE html>
<html>
<head>
</head>
<body ng-app="myapp">
<div ng-controller="try as ctl">
<input ng-model="ctl.ticket.nombre">
<textarea ng-model="ctl.ticket.code"></textarea>
<button ng-click="ctl.send()">Enviar</button>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.6/angular.min.js"></script>
<script>
var ws = new WebSocket("ws://localhost:2645/service");
ws.binaryType = "arraybuffer";
ws.onopen = function () {
console.log('connection is opened!!!');
};
ws.onmessage = function (evt) {
console.log(arrayBufferToString(evt.data))
};
ws.onclose = function () {
console.log("Connection is Closed...")
};
function arrayBufferToString(buffer) {
var arr = new Uint8Array(buffer);
var str = String.fromCharCode.apply(String, arr);
return decodeURIComponent(escape(str));
}
var app = angular.module('myapp', []);
app.controller('try', function () {
this.ticket= {nombre:'', estado:''}
this.send = () => {
var toSend= JSON.stringify(this.ticket);
ws.send(toSend);
}
});
</script>
</body>
</html>
然后从 html 发送一个 ZPL 代码（写在 textarea 代码上）；
^XA
^FO200,50^BY2^B3N,N,80,Y,N^FD0123456789^FS
^PQ1^XZ