Re: C# Remote Window Hooks - C# Discussion Boards

Re: Thread creation using reflection for the target?

1-May-07 9:55

I have a general service that starts up several WCF services. This all works great. Now I have two different thread processes I need to start. I would like to use a configuration file (XML) to define the classes and target methods and this requires that I use reflection to create the thread object correctly. So I basically have to recreate:

Thread newThread = new Thread(new ThreadStart(class.Method));

Any ideas or article someone can point me to? Is this even possible?

Thanks,

Michael

Ian Shlasko1-May-07 10:21

Re: Thread creation using reflection for the target?

1-May-07 10:21

Well, a ThreadStart may be a zero-parameter delegate, but that method can contain anything...

<br />
_obj = Get_My_Object_Through_Reflection_Somehow<br />
<br />
Thread newThread = new Thread(new ThreadStart(RunObjMethod));<br />
newThread.Start();<br />
<br />
...<br />
<br />
private void RunObjMethod()<br />
{<br />
  _obj.Method();<br />
}<br />

There are of course ways to clean this up... You could pass the object and a string with the method name to a private class, and have the class do something like the above code in its constructor, just to keep everything encapsulated. Make it nice and general, and hook up a static method to wrap the constructor, and you can make it look like:

<br />
StartInThread.Launch(myObj, "MethodName");<br />
<br />
...<br />
<br />
private class StartInThread<br />
{<br />
  object _obj;<br />
  string _methName;<br />
<br />
  public static void Launch(object obj, string methName)<br />
  {<br />
    new StartInThread(obj, methName);<br />
  }<br />
  private StartInThread(object obj, string methName)<br />
  {<br />
    _obj = obj; _methName = methName;<br />
    Thread thrd = new Thread(new ThreadStart(Run));<br />
    thrd.Name = methName;<br />
    thrd.IsBackground = true;<br />
    thrd.Start();<br />
  }<br />
<br />
  private void Run()<br />
  {<br />
    ...get a MethodInfo for _methName in _obj, and call it directly...<br />
  }<br />
}<br />

(Pardon any syntax errors, since I just typed that up in this box)

LongRange.Shooter1-May-07 10:58

Re: Thread creation using reflection for the target?

1-May-07 10:58

Thank you. Your code really did not help me at all but it did get me to thinking towards a solution.

I just need to define an interface:

public interface IThreadProcess
{
    bool TerminateThread{get; set;}
    ///<summary>
    /// all consumers of this interface must run a while ( !TerminateThread ){}
    ///</summary>
    void StartThreadProcess();
}

Then I just have to create an instance cast to the interface and VOILA I now have addressability to the method implementation.

PIEBALDconsult1-May-07 18:26

PIEBALDconsult

1-May-07 18:26

I was going to say:

May I suggest you look into System.ServiceProcess.ServiceBase.Run ( System.ServiceProcess.ServiceBase[] )

But I suppose your first sentence means you already do that.

Everything is possible.

C# Remote Window Hooks

Bourtree1-May-07 9:40

Bourtree

1-May-07 9:40

Has anyone out there had any experiance creating 'Remote' windows hooks for applications using C#. These are thread specific hooks - NOT global and NOT local.

I want to load an application using CreateProcess API get the thread id and create a remote hook with filters for the CBT and Keyboard hooks for that application.

I believe to create remote hooks you have to create a DLL that contains your filter functions and reference them in the SetWindowsHooksEx API function. All the C# examples available seem to create local hooks using the thread for the current application and subsequently the filter functions can reside locally, within the same application.

If a C# DLL is indeed required can I still use delegates to reference the filter functions within it?

Thanks

Regards

Phillip.

Re: C# Remote Window Hooks

LongRange.Shooter1-May-07 11:58

Re: C# Remote Window Hooks

1-May-07 11:58

If I understand your question correctly, you are probably wanting to do something that in not 'legal' within the context of C# managed code. Think of it. If you can do that with your application, what stops someone from writing a cookoos egg that launches the login window and hooks into the keyboard to steal you id and password.

That is probably why the examples are in the same application context.

Bourtree3-May-07 6:51

Bourtree

3-May-07 6:51

Yes, that is a valid point and I have noticed that some of the examples out there are for ‘legitimate’ password retrieval utilities. However, I can assure you my intentions are honorable and focused on extending the functionality of an ‘off the shelf’ business application for which no API exists.

For remote hooks it is necessary to have the filter functions in a DLL that is injected into the address space of the application at run time. Seemingly, given the nature of .NET and the CLR this allocation is not permissible as such. Would it be possible to write unmanaged C# code to achieve this objective? Can I still utilize the Win32 API’s using the P/Invoke layer if the code is managed? If not, what other means are there to utilize them?

Thanks for your help

Phillip.

Re: C# Remote Window Hooks

LongRange.Shooter3-May-07 14:56

array of reference type in heap

3-May-07 14:56

The only option is unmanaged C++. So if this is going to be a published application, let me know what it is so that I never buy it.

swjam1-May-07 8:59

swjam

1-May-07 8:59

say Triangle is a class and the following has been declared:

<br />
Triangle[] triangles = new Triangle[4];<br />
for (int i = 0; i != triangles.Length; i++)<br />
{<br />
    triangles[i] = new Triangle();<br />
}<br />

with respect to what's happening in the heap, are two codes below the same?
thanks!

<br />
Triangle[] copy = new Triangle[triangles.Length];<br />
for (int i = 0; i != copy.Length; i++)<br />
{<br />
    copy[i] = triangles[i];<br />
}<br />

Triangle[] copy = triangles;

I am a SysAdmin, I battle my own daemons.

Ian Shlasko1-May-07 9:13

1-May-07 9:13

They might be functionally identical, depending on how you use them, but they aren't the same.

Basically, you have:

triangles -> arrayObject: [ triangle1, triangle2, triangle3 ]

The first block of code would create:

copy -> copyOfArray: [ triangle1, triangle2, triangle3 ]
(copy is a pointer to a new array containing references to the same objects)

The second block would create:

copy -> arrayObject: [ triangle1, triangle2, triangle3 ]
(copy is a pointer to the original array)

Subtle difference, but in the first case, you could sort the copied array independently, and even add and remove elements without touching the original array. In the second case, sorting "copy" would sort "triangles".

~~(I'm assuming that Triangle is a class, not a struct. If it's a struct, then there's even more of a difference, because the first case would make a completely separate array of independent objects)~~

EDIT: Silly me, you said it was a class. Last paragraph is irrelevant

kubben1-May-07 9:14

1-May-07 9:14

I don't think you have actually created a copy yet. I think you just have a reference to the existing objects. If you truely wanted a copy you would need to do this:

Triangle[] copy = new Triangle[triangles.Length];
for (int i = 0; i != copy.Length; i++)
{
copy[i] = new Triangle();
copy[i] = triangles[i];
}
<./pre>

Otherwise you would have two objects that point to the same thing.

Ben

Ian Shlasko1-May-07 9:19

1-May-07 9:19

Even that wouldn't make an independent copy. You would need some sort of Clone() method, so the inner statement would be:

copy[i] = triangles[i].Clone() as Triangle;

kubben1-May-07 9:22

1-May-07 9:22

Right, the code should be:

copy[i] = new Triangle();
copy[i].property1 = triangles[i].property1;
copy[i].property2 = triangles[i].property2;
copy[i].property3 = triangles[i].property3;
...

for as many properties that exist.

If you implement a Triangle.Clone() then you could just do

copy[i] = triangle[i].Clone();

Ben

LongRange.Shooter1-May-07 9:50

1-May-07 9:50

This isn't an answer to your question, but this code creates two different types of arrays. The first (triangles) are a list of objects and the second (copy) is a list of reference pointers to the first collection. To do what you are showing there you need to so something like this:

public class Triangle:ICloneable
{
   public Triangle(){}
   protected Triangle(Triangle clone){ clone.Value = this.Value; }

   public object Clone(){return new Triangle(this);}
}

Then you change your loop as such :

for ( blah blah)
{
     copy[i] = triangles[i].Clone();
}

As to what things look like on the heap.....I have no idea.

Problme passing Double Quotes (") to query

Guffa1-May-07 9:52

Guffa

1-May-07 9:52

No, they are not the same.

DenClancy wrote:
Triangle[] copy = new Triangle[triangles.Length];
for (int i = 0; i != copy.Length; i++)
{
copy[i] = triangles[i];
}

This will give you a new array, but it contains references to the same objects as the original array.

DenClancy wrote:
Triangle[] copy = triangles;

This will only give you another reference to the same array.

---
single minded; short sighted; long gone;

Muhammad Nauman Yousuf1-May-07 6:54

Muhammad Nauman Yousuf

1-May-07 6:54

Hi,

I am using Windows Indexing services via the OleDB Driver.

Now everything works good, till i am to pass (") double quotes into the query

Sample query to pass
SELECT path FROM SCOPE() WHERE Matches("test*");

Now after all the process the VS 2005 just appends \ to my query
SELECT path FROM SCOPE() WHERE Matches(\"test*\");

"Mess with the Best, Die like the rest"

kubben1-May-07 7:15

1-May-07 7:15

Passing queries is a real bad idea to being with because of sql injection issues. Still to fix your problems you just need more double quotes. I believe your query will work if it is like this:
SELECT path FROM SCOPE() WHERE Matches("""test*""");

Hope that helps.
Ben

Muhammad Nauman Yousuf1-May-07 7:53

Muhammad Nauman Yousuf

1-May-07 7:53

Thx for the replying

Below is the original c# code

queryString = queryString + " MATCHES(""" + strExactPhrase.ToString() + """)";
* *
*'s are the points where i am getting an error "; expected" in VS 2005

Thank you!

"Mess with the Best, Die like the rest"

kubben1-May-07 7:59

1-May-07 7:59

Does this work:
queryString = queryString + " MATCHES(\"" + strExactPhrase.ToString() + "\")";

Ben

Ian Shlasko1-May-07 8:05

1-May-07 8:05

I think you're mixing up C# and VB.NET here. VB.NET uses pairs of quotes ("" -> "), while C# uses backslash-escapes (\" -> "). If you print the string to the debugger or watch windows, you WILL see the escape codes in C#, but that's not actually in the string.

So basically, stick with the original version, using \" to represent a double-quote, and don't worry if you see the backslash when debugging.

kubben1-May-07 8:10

1-May-07 8:10

You are right. You know I think I might have also gotten it mixed up with the single quote. You can have problems with that as well.

Ben

Ian Shlasko1-May-07 8:20

1-May-07 8:20

The single quote shouldn't cause you any problems in C#, since it has no special meaning inside double-quotes. That's only used to signify a character instead of a string.

kubben1-May-07 8:30

1-May-07 8:30

Really, try a query that searches for a lastname of o'leary. You can certainly have some problems with that. I have had more problems with this because of some dynamic sql creation. I have some stored procedures where you pass in some xml that is a parameter list. The xml is read into a table and then those parameters are used to dynamically create a specific seach query. In that case you for sure can have problems passing in single quotes.

Ben

Ian Shlasko1-May-07 8:48