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My Problem

I have a Problem which i can not solve my self. I dont want to use so much code, because i have multiple Classes which extend another class (in my case its called "Data").

I have a log file, where each Data Group is beginning with a specific Group Name, for example "MitarbeiterSet". The abstract Data-Class is used to prefent to much code, where I implemented variables like "String[] data" (for the data beeing parsed from the log file e.g. < 101 4 3 6 3 30 80 2 0 0 1 300 >) or "static String parseInduction", which is used to determin, if this Class is the right one to create Objects from.

I have another Class, called ParseMonitor, which creates the StreamReader to parse the log-file. So if the right Class is found, i induct the setDataArray(StreamReader sr) function from the right Class, to parse the Data Array. (At this point i have to tell you, that i need those different Classes, because i need to upload them to a sql server specificly.)

This static function creates an object of it self and uses the parseLine(String line) Function to fill the object with data from the given line.

WHAT I NEED.

I want to call the static function of any class, just by having the name of this class. So i dont have to use that much code and be able to add more classes.

Later on i want to call every class and use the uploadToServer() to Upload it to the server.

Is this possible?

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4 Answers 4

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1

Since your static method is creating an instance of its class anyway, I suggest a different approach:

Create an interface that all classes that contain ParseLine can implement. (Change out the return type for the correct one):

public interface IParseLine
{
    string ParseLine(string line);
}

Have all of the classes that contain ParseLine() implement IParseLine.

Create an instance of the class, cast it to an IParseLine, and execute the method:

IParseLine pl = Activator.CreateInstance(Type.GetType(className)) as IParseLine;
if (pl != null)
{
    string parsedString = pl.ParseLine(line);
    // ...
}

Edit From comments:

I want to create a while loop, which can be stated as followed: while{!sr.EndofStream){ line = sr.ReadLine(); for(int i = 0; i < classNames.length; i++){ if(line.Contains(classNames[i].MYINDICATOR){ CALL classNames[i] STATIC METHOD TO PARSE THE FOLLOWING LINES AND CREATE DATA Objects of its Class } }

I didn't test this, but you can change the code to something like this (caching the reflection required to get MYINDICATOR):

IList<KeyValuePair<string, Type>> typeIndicators = classNames.Select(x => {
    Type t = Type.GetType(x);
    string indicator = (string)t.GetField("MYINDICATOR", BindingFlags.Public | BindingFlags.Static).GetValue(null);
    return new KeyValuePair(indicator, t);
});

while (!sr.EndOfStream)
{
    line = sr.ReadLine();
    foreach (var types in typeIndicators)
    {
        if (line.Contains(types.Key))
        {
             IParseLine pl = Activator.CreateInstance(types.Value) as IParseLine;
             if (pl != null)
             {
                 string parsedString = pl.ParseLine(line);
             }
        }
    }
}
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4 Comments

I want to create a while loop, which can be stated as followed: while{!sr.EndofStream){ line = sr.ReadLine(); for(int i = 0; i < classNames.length; i++){ if(line.Contains(classNames[i].MYINDICATOR){ CALL classNames[i] STATIC METHOD TO PARSE THE FOLLOWING LINES AND CREATE DATA Objects of its Class } }
No reason that you can't put that into a loop, or a helper function, or whatever.
I had to edit a lot, sorry for that. Its important to state, that i need this MYINDICATOR stuff. Another Idea would be to create a first object of every class and use this one to get the MYINDICATOR variable and to create and save the following objects. But i thought this might be possible the "tricky" way
You need to reflect against the classes to get the constant MYINDICATOR. I added an extended example to illustrate.
1

I want to call the static function of any class, just by having the name of this class.

Well, you can use Type.GetType(className) to get a Type (note that the name needs to at least be fully qualified including the namespace, and may also need the assembly name depending on your exact scenario), then Type.GetMethod to get a MethodInfo. Finally, call MethodBase.Invoke to invoke the method.

If you could use typeof(Foo) instead of using a string, it would make the code simpler and more robust.

(Side-note: if your methods are really called parseLine, parseInduction, setDataArray etc, you should consider renaming them to follow .NET naming conventions :)

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5 Comments

i am coming from Java, so this is really hard for me to follow - haha
@DominikVogt: It's the equivalent of Class.forName, Class.getDeclaredMethod, Method.invoke. But I'd strongly recommend that you stop using Java idioms, and embrace C# idioms - particularly naming conventions :)
Im going to stick to it :) Type myType = Type.GetType("DienstGruppe"); MethodInfo info = myType.GetMethod("setDataArray"); info.Invoke(sr); I don't get my error. Do you see my mistake? Im getting CS1501 error, but dont know the cause. I think it might be sth about the namespace. I am in the same namespace as my class i want to invoke the function though.
@DominikVogt: Well CS1501 sounds like a compile-time error. I don't have those compiler codes memorized - but it should give you enough information and tell you which line the problem is on. I suspect you actually want info.Invoke(null, new object[] { sr }) though.
I think this is going to help me link Thank you though
1

I think I see where you're coming from. In this simple exmaple below, I have a static class with a method in it (nothing amazing about that).

public static class MyStaticClass
{
    public static DateTime GetTime()
    {
        return DateTime.Now;
    }
}

If I want to invoke that method using reflection, I can just use the following code, but it does assume that the MyStaticClass class is available via a reference or inthe same project etc.

MethodInfo method = typeof(MyStaticClass).GetMethod("GetTime");
object result = method.Invoke(null, null);

if (result is DateTime)
{
    Console.WriteLine(((DateTime)result).ToLongTimeString());
}

What you seem ot be asking for is a moethod of doing this when you don't have a reference to the class. In which case, try something like this:

MethodInfo method = Type.GetType("PocStaticReflect.MyStaticClass, PocStaticReflect, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null").GetMethod("GetTime");
object result = method.Invoke(null, null);

if (result is DateTime)
{
    Console.WriteLine(((DateTime)result).ToLongTimeString());
}

Notice the fully qualified class name!

If you get that working, then you can simply loop though your class names and call the method you desire. Obviously, you'll probably want more error checking and more detail in the GetMethod() calls, but this shlud give you the gist of it. I've done something similar before looping though assemblies in a folder to pickup plug-ins for an application. That time, each of the classes implemented an interface to make them easier to locate, which may be helpful path to follow.

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Comments

1

Or try this:

 private static object GetResultFromStaticMethodClass(string qualifiedClassName, string method)
 {
      Type StaticClass = Type.GetType(qualifiedClassName);
      MethodInfo methodInfo = StaticClass.GetMethod(method);
      object result = methodInfo.Invoke(null, null);
      return result;
 }

Use:

object result = GetResultFromStaticMethodClass(
    "Utilities.StringHelper,DaProject",
    "ToList"
);

This call the static method ToList in the StringHelper class, in the Utilities namespace, in the DaProject project (same assembly and project name).

If you need parameters, add them in the second parameter in the methodInfo.Invoke(null, null) call

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