斑马打印机客户端GET和POST，以及后端两种打印方式。

背景环境：打印机安装在客户端外网。当用户登录时，通过ajax取服务器数据，返回打印机命令，然后客户端通过JS发送给斑马打印机。

1、使用Get方式打印

1.1 前端页面js代码

jQuery(function () {
$("#btnRePrint").click(function () {
//var cartonId = "450002241530221";
var cartonId = "";
if ($("input[name='checkbox']:checked").length == 1) {
// 1、获取重打打的数据，返回箱号
var trs = $("#data tr");
for (var i = 0; i < trs.length; i++) {
if ($("#checkbox_" + i).attr('checked') == true) {
var strVendorId = trs[i].cells[2].innerText; // 供应商
var strPoId = trs[i].cells[4].innerText; // 采购订单
var strPoSeq = trs[i].cells[5].innerText; // 采购订单行项
var strMatId = trs[i].cells[7].innerText // 物料号

$.ajax({
url: "Handler/CreatedliverGetRePrintData.ashx?VendorId=" + strVendorId + "&PoId=" + strPoId + "&PoSeq=" + strPoSeq + "&MatId=" + strMatId,
async:false,
success: function (result, status) {
debugger;
cartonId = result;
}
});
}
}

// 2、调用Web Api 返回zpl命令
//jQuery.support.cors = true;
$.ajax({
url: "Handler/CreatedeliverRePrint_Ajax.ashx?CartonId=" + cartonId,
async:false,
success: function (result, status) {
debugger;

var arrayResult = result.split('|');
// 返回消息格式：S|Zpl命令，E|错误提醒
if (arrayResult[0].toUpperCase() == "\"ZPL".toUpperCase()) {
var zpl = arrayResult[1].substring(0, arrayResult[1].length - 1);
Print(zpl);
alert("重打成功！");
}
if (arrayResult[0].toUpperCase() == "\"Tip".toUpperCase()) {
alert(arrayResult[1]);
}
if (arrayResult[0].toUpperCase() == "\"Err".toUpperCase()) {

}
}
});
} else {
alert("一次只能重打一行");
}
});
});

1.2 后台ajax代码

public class CreatedeliverRePrint_Ajax_ashx : IHttpHandler
{
string apiBaseUri = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_BaseUri"].ToString(), "ME Co,. Ltd.");
string userName = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_UserName"].ToString(), "ME Co,. Ltd.");
string password = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_PassWord"].ToString(), "ME Co,. Ltd.");
string clientId = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_ClientId"].ToString(), "ME Co,. Ltd.");
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
string strCartonId = context.Request["CartonId"].ToString().Trim();
if (context.Request.Params.Count > 0)
{
var tokenStr = IndexApi.Adapter.GetToken(apiBaseUri, userName, password);
var result = IndexApi.Adapter.CallApiGet(apiBaseUri, "/api/zpl/Get/" + strCartonId, tokenStr, clientId);
context.Response.Write(result);
context.Response.End();
}
}

public bool IsReusable
{
get
{
return false;
}
}
}

2 使用post方式打印

2.1 前端页面js代码

function Print(strZplCommand) {
//var zpl = document.getElementById("zpl").value;
var zpl = strZplCommand;
var ip_addr = document.getElementById("hidIpAddress").value;
//var output = document.getElementById("output");
//var url = "http://" + ip_addr + "/pstprnt";

var url = "http://" + ip_addr + "/pstprnt";
var request = new Request(url, {
method: 'POST',
mode: 'no-cors',
cache: 'no-cache',
body: zpl
});

fetch(request)
.then(function (response) {

// Important : in 'no-cors' mode you are allowed to make a request but not to get a response
// even if in 'Network' Tab in chrome you can actually see printer response
// response.ok will always be FALSE and response.text() null
/*if (!response.ok) {
throw Error(response.statusText);
}*/
return true;
})

.catch(function (error) {

// note : if printer address is wrong or printer not available, you will get a "Failed to fetch"
console.log(error);

});
}

2.2 后端ajax代码

string apiBaseUri = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_BaseUri"].ToString(), "ME Co,. Ltd.");
string userName = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_UserName"].ToString(), "ME Co,. Ltd.");
string password = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_PassWord"].ToString(), "ME Co,. Ltd.");
string clientId = EncryptLib.DecryptString(System.Configuration.ConfigurationManager.AppSettings["Api_ClientId"].ToString(), "ME Co,. Ltd.");

context.Response.ContentType = "text/plain";
if (context.Request.Params.Count > 0)
{
DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[]{
new DataColumn("DeliveryOrderId",typeof(string))
,new DataColumn("PoId",typeof(string))
,new DataColumn("SeqNo",typeof(string))
,new DataColumn("Qty",typeof(string))
,new DataColumn("TransportQty",typeof(string))
,new DataColumn("VendorBatchNo",typeof(string))
});
DataRow row = null;

for (int i = 0; i < context.Request.Form.AllKeys.Count() / 6; i++)
{
row = dt.NewRow();
//row["OrderSeq"] = "450002241530";
row["DeliveryOrderId"] = context.Request.Form["boxs["+i+"][DeliveryOrderId]"];
row["PoId"] = context.Request.Form["boxs[" + i + "][PoId]"];
row["SeqNo"] = context.Request.Form["boxs[" + i + "][SeqNo]"];
row["Qty"] = context.Request.Form["boxs[" + i + "][Qty]"];
row["TransportQty"] = context.Request.Form["boxs[" + i + "][TransportQty]"];
row["VendorBatchNo"] = context.Request.Form["boxs[" + i + "][VendorBatchNo]"];
dt.Rows.Add(row);
}
dt.AcceptChanges();

#if DEBUG
dt.Clear();
DataRow rowTest = null;
rowTest = dt.NewRow();
rowTest["DeliveryOrderId"] = "20180125085905";
rowTest["PoId"] = "4500022415";
rowTest["SeqNo"] = "10";
rowTest["Qty"] = "47";
rowTest["TransportQty"] = "300";
rowTest["VendorBatchNo"] = "";
dt.Rows.Add(rowTest);

rowTest = dt.NewRow();
rowTest["DeliveryOrderId"] = "20180125085905";
rowTest["PoId"] = "4500022415";
rowTest["SeqNo"] = "30";
rowTest["Qty"] = "50";
rowTest["TransportQty"] = "300";
rowTest["VendorBatchNo"] = "";
dt.Rows.Add(rowTest);

dt.AcceptChanges();

#endif

string jsonData = JsonConvert.SerializeObject(dt);
jsonData = "{\"boxs\":"+jsonData;
jsonData = jsonData + "}";

// 调用接口
var tokenStr = IndexApi.Adapter.GetToken(apiBaseUri, userName, password);
var result = IndexApi.Adapter.CallApiPost(jsonData,apiBaseUri,"/api/zpl/post",tokenStr,clientId);

context.Response.Write(result);
context.Response.End();
}
}

public bool IsReusable
{
get
{
return false;
}
}

3、后端打印关键代码 RawPrinterHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

using System.Text;
using System.IO;
using System.Drawing;
using System.Drawing.Printing;
using System.Runtime.InteropServices;

namespace BarCodePrintApi
{
public class RawPrinterHelper
{
// 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, out IntPtr hPrinter, 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, out 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)
{
Int32 dwError = 0, dwWritten = 0;
IntPtr hPrinter = new IntPtr(0);
DOCINFOA di = new DOCINFOA();
bool bSuccess = false; // Assume failure unless you specifically succeed.

di.pDocName = "My C#.NET RAW Document";
di.pDataType = "RAW";

// Open the printer.
if (OpenPrinter(szPrinterName.Normalize(), out 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, out 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;
}

/// <summary>
/// 发送文件到打印机
/// </summary>
/// <param name="szPrinterName">打印机名称</param>
/// <param name="szFileName">文件</param>
/// <returns></returns>
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;

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;
}

/// <summary>
/// 发送字符串到打印机
/// </summary>
/// <param name="szPrinterName">打印机名称</param>
/// <param name="szString">指令</param>
/// <returns></returns>
public static bool SendStringToPrinter1(string szPrinterName, string szString)
{
IntPtr pBytes;
Int32 dwCount;
// 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.
//Encoding.GetEncoding("GB2312").GetBytes(szString);
pBytes = Marshal.StringToCoTaskMemAnsi(szString);

// Send the converted ANSI string to the printer.
SendBytesToPrinter(szPrinterName, pBytes, dwCount);
Marshal.FreeCoTaskMem(pBytes);
return true;
}
/// <summary>
/// 打印标签带有中文字符的ZPL指令
/// </summary>
/// <param name="printerName">打印机名称</param>
/// <param name="szString">指令</param>
/// <returns></returns>
public static string SendStringToPrinter(string printerName, string szString)
{
byte[] bytes = Encoding.GetEncoding("GB2312").GetBytes(szString); //转换格式
IntPtr ptr = Marshal.AllocHGlobal(bytes.Length + 2);
try
{
Marshal.Copy(bytes, 0, ptr, bytes.Length);
SendBytesToPrinter(printerName, ptr, bytes.Length);
return "success";
}
catch(Exception ex)
{
return ex.Message;
}
finally
{
Marshal.FreeCoTaskMem(ptr);
}
}

/// <summary>
/// 网络打印
/// </summary>
/// <param name="ip"></param>
/// <param name="port"></param>
/// <param name="szString"></param>
/// <returns></returns>
public static string SendStringToNetPrinter(string ip, int port, string szString)
{
try
{
//打开连接
System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient();
client.Connect(ip, port);

//写入zpl命令
System.IO.StreamWriter writer = new System.IO.StreamWriter(client.GetStream());
writer.Write(szString);
writer.Flush();

//关闭连接
writer.Close();
client.Close();

return "success";
}
catch (Exception ex)
{
return ex.Message;
}
}
}
}