使用C＃谷歌云打印 [英] Google Cloud Print using C#
问题描述
我尝试使用C＃使用谷歌云打印。互联网刚一例如，谁写乔希戈贝尔。
我不会公布完整的例子，这里是发送一个文件打印的唯一方法：
I try to use Google Cloud Print using C#. Internet has just one example, who wrote Josh Goebel. I will not publish the complete example, here is the only method that sends a file to print:
public CloudPrintJob PrintDocument(string printerId, string title, byte[] document)
{
try
{
string authCode;
if (!Authorize(out authCode))
return new CloudPrintJob() { success = false };
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.google.com/cloudprint/submit?output=json");
request.Method = "POST";
string queryString =
"printerid=" + HttpUtility.UrlEncode(printerId) +
"&capabilities=" + HttpUtility.UrlEncode("") +
"&contentType=" + HttpUtility.UrlEncode("application/pdf") +
"&title=" + HttpUtility.UrlEncode(title) +
"&content=" + HttpUtility.UrlEncode(Convert.ToBase64String(document));
byte[] data = new ASCIIEncoding().GetBytes(queryString);
request.Headers.Add("X-CloudPrint-Proxy", Source);
request.Headers.Add("Authorization", "GoogleLogin auth=" + authCode);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
Stream stream = request.GetRequestStream();
stream.Write(data, 0, data.Length);
stream.Close();
// Get response
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string responseContent = new StreamReader(response.GetResponseStream()).ReadToEnd();
DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(CloudPrintJob));
MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(responseContent));
CloudPrintJob printJob = serializer.ReadObject(ms) as CloudPrintJob;
return printJob;
}
catch (Exception ex)
{
return new CloudPrintJob() { success = false, message = ex.Message };
}
}
我运行此代码，然后有是我的打印机的接口，但是打印没有发生。我的打印机的接口说，要打印的页面0，以及文件大小
不与所述一个我发送到打印机重合
I run this code, then there is an interface of my printer, but print is not happening. The interface of my printer says that the pages to print 0, and the file size does not coincide with the one I sent to the printer.
谷歌云打印表示，任务（作业）被成功添加，但在谷歌云打印的文件旁边显示错误的名义接口。
Google Cloud Print says that the task(job) is successfully added, but at the interface of Google Cloud Print next to the name of the document display "Error".
我认为可能与 HttpUtility.UrlEncode 或 Convert.ToBase64String ，但我试过逆向转换的问题 - 一切正常
I thought that might have a problem with HttpUtility.UrlEncode or Convert.ToBase64String, but I tried the reverse transformation - everything works.
有没有人有什么想法？
推荐答案
我很欣赏这个问题是有点老了，但我最近不得不看看这个东西，我在工作中做的，而张贴的示例代码开始我关在正确的方向它没有把我相当一段时间才能得到它完全正常工作。
I appreciate this question is a little old now, but I've recently had to look at this for something I'm doing at work, and whilst the sample code posted started me off in the right direction it did take me quite a while to get it working completely.
所描述的打印机列表功能的工作确定，但我不能让提交正常工作，它只是直奔错误的OP描述。
The "list printers" function worked OK as described, but I couldn't get the Submit working properly, it just went straight to Error as the OP describes.
分析在Chrome中使用招实际提出请求，看着在谷歌网站上的PHP示例代码后，我发现提交需要的是一个多部分MIME消息或将无法正常工作。
After profiling an actual submit request in Chrome using Fiddler, and looking at the PHP sample code on google's website, I discovered that the submit needed to be a multipart MIME message or it wouldn't work properly.
这是它终于得到了提交操作工作HTTP POST消息的例子。请注意，GCP打印机ID必须在请求URL中传递，和数据（无论它是PDF，JPG或PNG）需要被Base64编码和正确的MIME类型集（应用/ PDF格式，图像/ JPEG ..对于内容块（最后一个在下面的列表））：
This is an example of the HTTP POST message which finally got the Submit operation working. Note that the gcp Printer Id needs to be passed in the request URL, and the data (whether it be a PDF, JPG or PNG) needs to be Base64 encoded and the correct mime type set (application/pdf, image/jpeg ...) for the "content" block (the last one in the list below):
POST http://www.google.com/cloudprint/submit?printerid=<printerid>&output=json HTTP/1.1
Host: www.google.com
Content-Length: 44544
X-CloudPrint-Proxy: Google-JS
Content-Type: multipart/form-data; boundary=----CloudPrintFormBoundaryqeq6g6ncj5v7
------CloudPrintFormBoundaryqeq6g6ncj5v7
Content-Disposition: form-data; name="capabilities"
{"capabilities":[{}]}
------CloudPrintFormBoundaryqeq6g6ncj5v7
Content-Disposition: form-data; name="contentType"
dataUrl
------CloudPrintFormBoundaryqeq6g6ncj5v7
Content-Disposition: form-data; name="title"
zodiac-pig-pic.jpg
------CloudPrintFormBoundaryqeq6g6ncj5v7
Content-Disposition: form-data; name="content"
data:image/jpeg;base64,JVBERi0xLjQKJeHp69MKMiAwIG...2NgolJUVPRg==
------CloudPrintFormBoundaryqeq6g6ncj5v7--
物联网很明显，当你在盯着的东西不知道为什么它不工作！）的最后边界的实例有在最后两个额外的连字符，那我需要摆脱C＃Expect100Continue头（使用request.ServicePoint.Expect100Continue = 。假）
Things which tripped me up were that the Boundary value specified in the header has 2 less hyphens (--) than the actual usage of them (not obvious when you're staring at something wondering why it's not working!), the very last boundary instance has two additional hyphens at the end, and that I needed to get rid of the C# Expect100Continue header (by using request.ServicePoint.Expect100Continue = false).
更新：这是我当时写的完整代码，如果它可以帮助任何人出来
UPDATE: Here is the complete code I wrote at the time, in case it helps anyone out.
using System;
using System.Configuration;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Runtime.Serialization.Json;
using System.Text;
using GoogleCloudPrintServices.DTO;
namespace GoogleCloudPrintServices.Support
{
public class GoogleCloudPrint
{
public string UserName { get; set; }
public string Password { get; set; }
public string Source { get; set; }
private const int ServiceTimeout = 10000;
public GoogleCloudPrint (String source)
{
Source = source;
}
public CloudPrintJob PrintDocument (string printerId, string title, byte[] document, String mimeType)
{
try
{
string authCode;
if (!Authorize (out authCode))
return new CloudPrintJob { success = false };
var b64 = Convert.ToBase64String (document);
var request = (HttpWebRequest)WebRequest.Create ("http://www.google.com/cloudprint/submit?output=json&printerid=" + printerId);
request.Method = "POST";
// Setup the web request
SetupWebRequest (request);
// Add the headers
request.Headers.Add ("X-CloudPrint-Proxy", Source);
request.Headers.Add ("Authorization", "GoogleLogin auth=" + authCode);
var p = new PostData ();
p.Params.Add (new PostDataParam { Name = "printerid", Value = printerId, Type = PostDataParamType.Field });
p.Params.Add (new PostDataParam { Name = "capabilities", Value = "{\"capabilities\":[{}]}", Type = PostDataParamType.Field });
p.Params.Add (new PostDataParam { Name = "contentType", Value = "dataUrl", Type = PostDataParamType.Field });
p.Params.Add (new PostDataParam { Name = "title", Value = title, Type = PostDataParamType.Field });
p.Params.Add (new PostDataParam
{
Name = "content",
Type = PostDataParamType.Field,
Value = "data:" + mimeType + ";base64," + b64
});
var postData = p.GetPostData ();
Trace.WriteLine (postData);
byte[] data = Encoding.UTF8.GetBytes (postData);
request.ContentType = "multipart/form-data; boundary=" + p.Boundary;
Stream stream = request.GetRequestStream ();
stream.Write (data, 0, data.Length);
stream.Close ();
// Get response
var response = (HttpWebResponse)request.GetResponse ();
var responseContent = new StreamReader (response.GetResponseStream ()).ReadToEnd ();
var serializer = new DataContractJsonSerializer (typeof (CloudPrintJob));
var ms = new MemoryStream (Encoding.Unicode.GetBytes (responseContent));
var printJob = serializer.ReadObject (ms) as CloudPrintJob;
return printJob;
}
catch (Exception ex)
{
return new CloudPrintJob { success = false, message = ex.Message };
}
}
public CloudPrinters Printers
{
get
{
var printers = new CloudPrinters ();
string authCode;
if (!Authorize (out authCode))
return new CloudPrinters { success = false };
try
{
var request = (HttpWebRequest)WebRequest.Create ("http://www.google.com/cloudprint/search?output=json");
request.Method = "POST";
// Setup the web request
SetupWebRequest (request);
// Add the headers
request.Headers.Add ("X-CloudPrint-Proxy", Source);
request.Headers.Add ("Authorization", "GoogleLogin auth=" + authCode);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = 0;
var response = (HttpWebResponse)request.GetResponse ();
var responseContent = new StreamReader (response.GetResponseStream ()).ReadToEnd ();
var serializer = new DataContractJsonSerializer (typeof (CloudPrinters));
var ms = new MemoryStream (Encoding.Unicode.GetBytes (responseContent));
printers = serializer.ReadObject (ms) as CloudPrinters;
return printers;
}
catch (Exception)
{
return printers;
}
}
}
private bool Authorize (out string authCode)
{
var result = false;
authCode = "";
var queryString = String.Format ("https://www.google.com/accounts/ClientLogin?accountType=HOSTED_OR_GOOGLE&Email={0}&Passwd={1}&service=cloudprint&source={2}",
UserName, Password, Source);
var request = (HttpWebRequest)WebRequest.Create (queryString);
// Setup the web request
SetupWebRequest (request);
var response = (HttpWebResponse)request.GetResponse ();
var responseContent = new StreamReader (response.GetResponseStream ()).ReadToEnd ();
var split = responseContent.Split ('\n');
foreach (var s in split)
{
var nvsplit = s.Split ('=');
if (nvsplit.Length == 2)
{
if (nvsplit[0] == "Auth")
{
authCode = nvsplit[1];
result = true;
}
}
}
return result;
}
private static void SetupWebRequest (HttpWebRequest webRequest)
{
// Get the details
var appSettings = ConfigurationManager.AppSettings;
// Create some credentials
if (!String.IsNullOrWhiteSpace (appSettings["ProxyUsername"]))
{
var cred = new NetworkCredential (appSettings["ProxyUsername"], appSettings["ProxyPassword"],
appSettings["ProxyDomain"]);
// Set the credentials
webRequest.Credentials = cred;
webRequest.Proxy = WebRequest.DefaultWebProxy;
webRequest.Proxy.Credentials = cred;
}
// Set the timeout
webRequest.Timeout = ServiceTimeout;
webRequest.ServicePoint.ConnectionLeaseTimeout = ServiceTimeout;
webRequest.ServicePoint.MaxIdleTime = ServiceTimeout;
// Turn off the 100's
webRequest.ServicePoint.Expect100Continue = false;
}
}
}
using System.Runtime.Serialization;
namespace GoogleCloudPrintServices.DTO
{
[DataContract]
public class CloudPrinter
{
[DataMember (Order = 0)]
public string id { get; set; }
[DataMember (Order = 1)]
public string name { get; set; }
[DataMember (Order = 2)]
public string description { get; set; }
[DataMember (Order = 3)]
public string proxy { get; set; }
[DataMember (Order = 4)]
public string status { get; set; }
[DataMember (Order = 5)]
public string capsHash { get; set; }
[DataMember (Order = 6)]
public string createTime { get; set; }
[DataMember (Order = 7)]
public string updateTime { get; set; }
[DataMember (Order = 8)]
public string accessTime { get; set; }
[DataMember (Order = 9)]
public bool confirmed { get; set; }
[DataMember (Order = 10)]
public int numberOfDocuments { get; set; }
[DataMember (Order = 11)]
public int numberOfPages { get; set; }
}
}
using System.Collections.Generic;
using System.Runtime.Serialization;
namespace GoogleCloudPrintServices.DTO
{
[DataContract]
public class CloudPrinters
{
[DataMember (Order = 0)]
public bool success { get; set; }
[DataMember (Order = 1)]
public List<CloudPrinter> printers { get; set; }
}
}
using System.Runtime.Serialization;
namespace GoogleCloudPrintServices.DTO
{
[DataContract]
public class CloudPrintJob
{
[DataMember (Order = 0)]
public bool success { get; set; }
[DataMember (Order = 1)]
public string message { get; set; }
}
}
using System;
using System.Collections.Generic;
using System.Text;
namespace GoogleCloudPrintServices.Support
{
internal class PostData
{
private const String CRLF = "\r\n";
public string Boundary { get; set; }
private List<PostDataParam> _mParams;
public List<PostDataParam> Params
{
get { return _mParams; }
set { _mParams = value; }
}
public PostData ()
{
// Get boundary, default is --AaB03x
Boundary = "----CloudPrintFormBoundary" + DateTime.UtcNow;
// The set of parameters
_mParams = new List<PostDataParam> ();
}
public string GetPostData ()
{
var sb = new StringBuilder ();
foreach (var p in _mParams)
{
sb.Append ("--" + Boundary).Append (CRLF);
if (p.Type == PostDataParamType.File)
{
sb.Append (string.Format ("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"", p.Name, p.FileName)).Append (CRLF);
sb.Append ("Content-Type: ").Append (p.FileMimeType).Append (CRLF);
sb.Append ("Content-Transfer-Encoding: base64").Append (CRLF);
sb.Append ("").Append (CRLF);
sb.Append (p.Value).Append (CRLF);
}
else
{
sb.Append (string.Format ("Content-Disposition: form-data; name=\"{0}\"", p.Name)).Append (CRLF);
sb.Append ("").Append (CRLF);
sb.Append (p.Value).Append (CRLF);
}
}
sb.Append ("--" + Boundary + "--").Append (CRLF);
return sb.ToString ();
}
}
public enum PostDataParamType
{
Field,
File
}
public class PostDataParam
{
public string Name { get; set; }
public string FileName { get; set; }
public string FileMimeType { get; set; }
public string Value { get; set; }
public PostDataParamType Type { get; set; }
public PostDataParam ()
{
FileMimeType = "text/plain";
}
}
}
这篇关于使用C＃谷歌云打印的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
