一. 应用场景
开发一个课件在线学习功能，要求将WORD, EXCEL, PPT类型课件可在线打开学习；最初设想使用第三方office插件，无奈价格太高放弃使用；
我们最终的方案是：利用office自身的另存为功能，在服务器将上传的office文件转化为pdf格式，然后网页打开pdf文件实现在线学习功能；
项目实现方案：新建一个windows自启的service安装在服务器，这个服务里面会建立一个HttpListener，用于监听文件转换的请求，请求来了后交给ServiceHandle处理，ServiceHandle会调用ConvertHelper把指定目录下的office文件转化为pdf，并放在相同目录下，以供在线学习使用；
二. 工具及环境
- VS2019
- Office：本地开发2016版；服务器2010版
- 开发环境 win10
- 服务器环境 windows server 2012 R2
- VS开发使用到的nuget包：NetOffice
三. 创建windows server项目
VS2012下开发Windows服务， 参考地址：
https://www.cnblogs.com/zhy-1992/p/6515850.html
基本按照这个思路开发出一个基础service完全没问题；这里需要提醒下的是：项目的文件路径不要带有空格，否则在执行bat批处理操作时会出现问题。
四. 使用NetOffice实现文件转换
上面只是创建一个服务， 真正转换的核心功能还没开始，这时我们需要利用NetOffice插件；
项目目录：
image.png
利用nuget包管理器安装所需包，这是项目的packages.config文件：
<?xml version="1.0" encoding="utf-8"?>
<packages>
<package id="NetOffice.Core" version="1.7.4.4" targetFramework="net452" />
<package id="NetOffice.Excel" version="1.7.4.4" targetFramework="net452" />
<package id="NetOffice.PowerPoint" version="1.7.4.4" targetFramework="net452" />
<package id="NetOffice.Word" version="1.7.4.4" targetFramework="net452" />
<package id="Newtonsoft.Json" version="12.0.3" targetFramework="net45" />
</packages>
转换核心代码：ConvertHelper.cs
public class ConvertHelper
{
public static void ConvetToPdf(string sourcePath, string targetPath)
{
if (!File.Exists(sourcePath))
{
throw new Exception(string.Format("文件{0}不存在", sourcePath));
}
if (File.Exists(targetPath))
{
throw new Exception(string.Format("目标文件{0}已存在", targetPath));
}
LogHelper.Info<Program>("开始转换:" + Path.GetFileName(sourcePath));
var targetDirectory = Path.GetDirectoryName(targetPath);
if (!Directory.Exists(targetDirectory))
{
Directory.CreateDirectory(targetDirectory);
}
var ext = Path.GetExtension(sourcePath).ToLower();
if (ext == ".ppt" || ext == ".pptx")
{
ConvertPptToPdf(sourcePath, targetPath);
}
else if (ext == ".doc" || ext == ".docx")
{
ConvertDocumentToPdf(sourcePath, targetPath);
}
else if (ext == ".xls" || ext == ".xlsx")
{
ConvertExcelToPdf(sourcePath, targetPath);
}
else
{
LogHelper.Info<Program>("{0}不支持转换pdf", sourcePath);
return;
}
if (File.Exists(targetPath))
{
LogHelper.Info<Program>("转换成功:" + Path.GetFileName(sourcePath));
}
else
{
LogHelper.Info<Program>("转换失败:" + Path.GetFileName(sourcePath));
}
}
/// <summary>
/// 转换ppt文件到pdf文件（不支持超时终止）
/// </summary>
/// <param name="sourcePath"></param>
/// <param name="targetPath"></param>
private static void ConvertPptToPdf(string sourcePath, string targetPath)
{
NetOffice.PowerPointApi.Application application = null;
NetOffice.PowerPointApi.Presentation presentation = null;
var cts = new CancellationTokenSource();
var thread = new Thread(() =>
{
try
{
application = new NetOffice.PowerPointApi.Application();
presentation = application.Presentations.Open(sourcePath, true, NetOffice.OfficeApi.Enums.MsoTriState.msoTrue, false);
presentation.SaveCopyAs(targetPath, NetOffice.PowerPointApi.Enums.PpSaveAsFileType.ppSaveAsPDF);
}
catch (Exception ex)
{
if (ex.InnerException != null && ex.InnerException is ThreadAbortException)
{
LogHelper.Info<Program>("ConvertPptToPdf: {0}操作超时", Path.GetFileName(sourcePath));
}
else
{
LogHelper.Error<Program>(ex, "ConvertPptToPdf: {0}出现异常", Path.GetFileName(sourcePath));
}
}
finally
{
if (presentation != null)
{
presentation.Close();
presentation = null;
}
if (application != null)
{
application.Quit();
application.Dispose();
application = null;
}
//killProccess("POWERPNT");
}
});
cts.Token.Register(() =>
{
thread.Abort();
});
cts.CancelAfter(Program.MaxThreads * 1000);
thread.Start();
thread.Join();
GC.Collect();
GC.WaitForPendingFinalizers();
}
/// <summary>
/// 转换word文件到pdf文件(支持超时终止)
/// </summary>
/// <param name="sourcePath"></param>
/// <param name="targetPath"></param>
private static void ConvertDocumentToPdf(string sourcePath, string targetPath)
{
NetOffice.WordApi.Application application = null;
NetOffice.WordApi.Document document = null;
var cts = new CancellationTokenSource();
var thread = new Thread(() =>
{
try
{
application = new NetOffice.WordApi.Application();
document = application.Documents.Open(sourcePath);
document.ExportAsFixedFormat(targetPath, NetOffice.WordApi.Enums.WdExportFormat.wdExportFormatPDF);
}
catch (Exception ex)
{
if (ex.InnerException != null && ex.InnerException is ThreadAbortException)
{
LogHelper.Info<Program>("ConvertDocumentToPdf: {0}操作超时", Path.GetFileName(sourcePath));
}
else
{
LogHelper.Error<Program>(ex, "ConvertDocumentToPdf: {0}出现异常", Path.GetFileName(sourcePath));
}
}
finally
{
if (document != null)
{
document.Close();
document = null;
}
if (application != null)
{
application.Quit();
application.Dispose();
application = null;
}
//killProccess("WINWORD");
}
});
cts.Token.Register(() =>
{
thread.Abort();
});
cts.CancelAfter(Program.MaxThreads * 1000);
thread.Start();
thread.Join();
GC.Collect();
GC.WaitForPendingFinalizers();
}
private static void ConvertExcelToPdf(string sourcePath, string targetPath)
{
NetOffice.ExcelApi.Application application = null;
NetOffice.ExcelApi.Workbook wookbook = null;
var cts = new CancellationTokenSource();
var thread = new Thread(() =>
{
try
{
application = new NetOffice.ExcelApi.Application();
wookbook = application.Workbooks.Open(sourcePath);
wookbook.ExportAsFixedFormat(NetOffice.ExcelApi.Enums.XlFixedFormatType.xlTypePDF, targetPath);
}
catch (Exception ex)
{
if (ex.InnerException != null && ex.InnerException is ThreadAbortException)
{
LogHelper.Info<Program>("ConvertExcelToPdf: {0}操作超时", Path.GetFileName(sourcePath));
}
else
{
LogHelper.Error<Program>(ex, "ConvertExcelToPdf: {0}出现异常", Path.GetFileName(sourcePath));
}
}
finally
{
if (wookbook != null)
{
wookbook.Close();
wookbook = null;
}
if (application != null)
{
application.Quit();
application.Dispose();
application = null;
}
//killProccess("EXCEL");
}
});
cts.Token.Register(() =>
{
thread.Abort();
});
cts.CancelAfter(Program.MaxThreads * 1000);
thread.Start();
thread.Join();
GC.Collect();
GC.WaitForPendingFinalizers();
}
public static void CleanProccess()
{
LogHelper.Info<Program>("CleanProccess Start");
killProccess("WINWORD");
killProccess("EXCEL");
LogHelper.Info<Program>("CleanProccess Finish");
}
private static void killProccess(string appName)
{
// Store all running process in the system
Process[] runingProcess = Process.GetProcesses();
for (int i = 0; i < runingProcess.Length; i++)
{
// compare equivalent process by their name
if (string.Equals(runingProcess[i].ProcessName, appName, StringComparison.OrdinalIgnoreCase))
{
try
{
// kill running process
runingProcess[i].Kill();
LogHelper.Info<Program>("Kill {0} [{1}]", appName, runingProcess[i].Id);
}
catch (Exception ex)
{
if (ex is System.InvalidOperationException)
{
//进程已经关闭
}
else
{
LogHelper.Error<Program>(ex, "Kill {0} [{1}] Error", appName, runingProcess[i].Id);
}
}
}
}
}
}
ServiceListener监听http请求，端口号默认8091；
public ServiceListener()
{
_stop = new ManualResetEvent(false);
_idle = new ManualResetEvent(false);
_busy = new Semaphore(Program.MaxThreads, Program.MaxThreads);
_listener = new HttpListener();
_listenerThread = new Thread(HandleRequests);
}
public void Start()
{
var url = String.Format(@"http://localhost:{0}/", Program.ListenerPort); // Port=8091
LogHelper.Info<ServiceListener>("Listenning Start:" + url);
_listener.Prefixes.Add(url);
_listener.Start();
_listenerThread.Start();
}
五. 系统调用http服务，转换文件
public void ConvertToPdf(string serviceUrl, string sourcePath, string pdfPath)
{
var url = $"{serviceUrl}?srcPath={sourcePath}&tarPath={pdfPath}";
using (var webClient = new WebClient())
{
var result = webClient.DownloadString(url);
}
}
至此，开发完毕，本地开发完成；
六. 本地测试功能
- 注册服务，执行注册服务.bat
- 启动服务，执行启动服务.bat
-
查看服务运行情况
image.png
但是测试转换时遇到了问题，日志错误为 "Office 检测到该文件有问题。为帮助保护您的计算机，此文件无法打开。"：
2020-05-02 09:04:22:248 Info [Thread9] 开始转换:a10a54166224453abdd8d4b809f15449.ppt
2020-05-02 09:04:25:379 Exception [Thread10] ConvertPptToPdf: a10a54166224453abdd8d4b809f15449.ppt出现异常 Exception:
System.Runtime.InteropServices.COMException (0x80004005): See inner exception(s) for details. ---> System.Reflection.TargetInvocationException: 调用的目标发生了异常。 ---> System.Runtime.InteropServices.COMException: Presentations.Open : Office 检测到该文件有问题。为帮助保护您的计算机，此文件无法打开。
--- 内部异常堆栈跟踪的结尾 ---
在 System.RuntimeType.InvokeDispMethod(String name, BindingFlags invokeAttr, Object target, Object[] args, Boolean[] byrefModifiers, Int32 culture, String[] namedParameters)
在 System.RuntimeType.InvokeMember(String name, BindingFlags bindingFlags, Binder binder, Object target, Object[] providedArgs, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParams)
在 NetOffice.Invoker.MethodReturn(COMObject comObject, String name, Object[] paramsArray)
在 NetOffice.Invoker.MethodReturn(COMObject comObject, String name, Object[] paramsArray)
在 NetOffice.PowerPointApi.Presentations.Open(String fileName, Object readOnly, Object untitled, Object withWindow)
在 LMS.DocumentConvertService.ConvertHelper.LMS.DocumentConvertService\Service\ConvertHelper.cs:行号 75
2020-05-02 09:04:33:477 Info [Thread9] 转换失败:a10a54166224453abdd8d4b809f15449.ppt
问题原因：service不能没有权限进行桌面交互；因此需要开启此权限；
相关资料：
https://www.cnblogs.com/94cool/archive/2010/04/12/1710261.html
https://www.cnblogs.com/ymworkroom/articles/6673989.html
https://blog.csdn.net/jiangxinyu/article/details/5397060
我才用了其中2种较简单解决方案：
- 修改代码，在ProjectInstaller.cs中ProjectInstaller类中重载OnAfterInstall
[RunInstaller(true)]
public partial class ProjectInstaller : System.Configuration.Install.Installer
{
public ProjectInstaller()
{
InitializeComponent();
}
protected override void OnAfterInstall(IDictionary savedState)
{
try
{
base.OnAfterInstall(savedState);
System.Management.ManagementObject myService = new System.Management.ManagementObject(
string.Format("Win32_Service.Name='{0}'", this.serviceInstaller1.ServiceName));
System.Management.ManagementBaseObject changeMethod = myService.GetMethodParameters("Change");
changeMethod["DesktopInteract"] = true;
System.Management.ManagementBaseObject OutParam = myService.InvokeMethod("Change", changeMethod, null);
}
catch (Exception)
{
}
}
}
- SC程序修改， 允许与桌面进行交互
用批处理的方式实现，加入如下命令到>启动服务.bat文件中
sc config MonitorService type=interact type=own
至此，本地开发环境转换服务成功运行。
接下来准备上服务器！！
