1. 源起：
仍然是模块化编程所引发的需求。产品经理难伺候，女产品经理更甚之~:p
纯属戏谑，技术方案与产品经理无关，芋头莫怪！
vcu10项目重构，要求各功能模块以独立进程方式实现，比如：音视频转换模块，若以独立进程方式实现，如何控制其暂停、继续等功能呢？
线程可以suspend、resume，c#内置的process没有此类方法，咋整？
山穷水尽疑无路，柳暗花明又一村。情到浓时清转薄，此情可待成追忆！
前篇描述了进程间数据传递方法，此篇亦以示例演示其间控制与数据交互方法。
2、未公开的api函数：ntsuspendprocess、ntresumeprocess
此类函数在msdn中找不到。
思其原因，概因它们介于windows api和 内核api之间，威力不容小觑。怕二八耙子程序员滥用而引发事端，因此密藏。
其实还有个ntterminateprocess，因process有kill方法，因此可不用。
但再隐秘的东西，只要有价值，都会被人给翻出来，好酒不怕巷子深么！
好，基于其，设计一个进程管理类，实现模块化编程之进程间控制这个需求。
3、processmgr
直上代码吧，封装一个进程管理单元：
public static class processmgr
{
/// <summary>
/// the process-specific access rights.
/// </summary>
[flags]
public enum processaccess : uint
{
/// <summary>
/// required to terminate a process using terminateprocess.
/// </summary>
terminate = 0x1,
/// <summary>
/// required to create a thread.
/// </summary>
createthread = 0x2,
/// <summary>
/// undocumented.
/// </summary>
setsessionid = 0x4,
/// <summary>
/// required to perform an operation on the address space of a process (see virtualprotectex and writeprocessmemory).
/// </summary>
vmoperation = 0x8,
/// <summary>
/// required to read memory in a process using readprocessmemory.
/// </summary>
vmread = 0x10,
/// <summary>
/// required to write to memory in a process using writeprocessmemory.
/// </summary>
vmwrite = 0x20,
/// <summary>
/// required to duplicate a handle using duplicatehandle.
/// </summary>
duphandle = 0x40,
/// <summary>
/// required to create a process.
/// </summary>
createprocess = 0x80,
/// <summary>
/// required to set memory limits using setprocessworkingsetsize.
/// </summary>
setquota = 0x100,
/// <summary>
/// required to set certain information about a process, such as its priority class (see setpriorityclass).
/// </summary>
setinformation = 0x200,
/// <summary>
/// required to retrieve certain information about a process, such as its token, exit code, and priority class (see openprocesstoken, getexitcodeprocess, getpriorityclass, and isprocessinjob).
/// </summary>
queryinformation = 0x400,
/// <summary>
/// undocumented.
/// </summary>
setport = 0x800,
/// <summary>
/// required to suspend or resume a process.
/// </summary>
suspendresume = 0x800,
/// <summary>
/// required to retrieve certain information about a process (see queryfullprocessimagename). a handle that has the process_query_information access right is automatically granted process_query_limited_information.
/// </summary>
querylimitedinformation = 0x1000,
/// <summary>
/// required to wait for the process to terminate using the wait functions.
/// </summary>
synchronize = 0x100000
}
[dllimport( "ntdll.dll" )]
private static extern uint ntresumeprocess([ in ] intptr processhandle);
[dllimport( "ntdll.dll" )]
private static extern uint ntsuspendprocess([ in ] intptr processhandle);
[dllimport( "kernel32.dll" , setlasterror = true )]
private static extern intptr openprocess(
processaccess desiredaccess,
bool inherithandle,
int processid);
[dllimport( "kernel32.dll" , setlasterror = true )]
[ return : marshalas(unmanagedtype. bool )]
private static extern bool closehandle([ in ] intptr handle);
public static void suspendprocess( int processid)
{
intptr hproc = intptr.zero;
try
{
// gets the handle to the process
hproc = openprocess(processaccess.suspendresume, false , processid);
if (hproc != intptr.zero)
ntsuspendprocess(hproc);
}
finally
{
// don't forget to close handle you created.
if (hproc != intptr.zero)
closehandle(hproc);
}
}
public static void resumeprocess( int processid)
{
intptr hproc = intptr.zero;
try
{
// gets the handle to the process
hproc = openprocess(processaccess.suspendresume, false , processid);
if (hproc != intptr.zero)
ntresumeprocess(hproc);
}
finally
{
// don't forget to close handle you created.
if (hproc != intptr.zero)
closehandle(hproc);
}
}
}
4、进程控制
我权且主进程为宿主，它通过process类调用子进程，得其id，以此为用。其调用代码为：
private void runtestprocess( bool hidden = false )
{
string apppath = path.getdirectoryname(application.executablepath);
string testapppath = path测试数据bine(apppath, "testapp.exe" );
var pi = new processstartinfo();
pi.filename = testapppath;
pi.arguments = this .handle.tostring();
pi.windowstyle = hidden ? processwindowstyle.hidden : processwindowstyle.normal;
this .childprocess = process.start(pi);
txtinfo.text = string .format( "子进程id：{0}\r\n子进程名：{1}" , childprocess.id, childprocess.processname);
...
}
控制代码为：
private void btnwork_click( object sender, eventargs e)
{
if ( this .childprocess == null || this .childprocess.hasexited)
return ;
if (( int )btnwork.tag == 0)
{
btnwork.tag = 1;
btnwork.text = "恢复" ;
processmgr.suspendprocess( this .childprocess.id);
}
else
{
btnwork.tag = 0;
btnwork.text = "挂起" ;
processmgr.resumeprocess( this .childprocess.id);
}
}
子进程以一定时器模拟其工作，向主进程抛进度消息：
private void timer_tick( object sender, eventargs e)
{
if (progressbar.value < progressbar.maximum)
progressbar.value += 1;
else
progressbar.value = 0;
if ( this .hosthandle != intptr.zero)
sendmessage( this .hosthandle, wm_progress, 0, progressbar.value);
}
代码量就这么的少，简单吧……
5、效果图：
为示例，做了两个图，其一为显示子进程，其二为隐藏子进程。
实际项目调用独立进程模块，是以隐藏方式调用的，以宿主展示其处理进度，如此图：
后记：
扩展思路，一些优秀的开源工具，如youtube_dl、ffmpeg等，都以独立进程方式存在，且可通过cmd管理通信。
以此进程控制原理，可以基于这些开源工具，做出相当不错的gui工具出来。毕竟相对于强大的命令行，人们还是以简单操作为方便。
原文链接：http://HdhCmsTestcnblogs测试数据/crwy/p/6622319.html
dy("nrwz");