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Thanks to everyone who helped with my previous question. I soon realized, however, that what I really need to do is to be able to cast the type, such as:
- This code is hypothetical, as to not complicate things further, but the real object in the program I am working on is a crystal report, but I want the viewer to work with any crystal report without having to hard code the viewer each time I create a new report. But if someone was able to answer this question, I could take it from there.
object SomeFunction ()<br />
{<br />
return UnknownObject;<br />
}
Now, while I dont know exactly what type UnknownObject is, I am sure no matter what it has a method called, lets say, ClearNum() - ya, kind of stupid, but Im trying to keep it simple to try to avoid getting an overcomplicated answer.
So lets say I want to ClearNum() on the object regardless of what type of object it is.
How can I accomplish the following:
void OnFormClose ()<br />
{<br />
object o = SomeFunction();<br />
((o.GetType())o).ClearNum();
}
Thanks if anyone knows the answer It would help me be a much better programmer.
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If the UnknownObject always has ClearNum() then it is likely that all objects returned by the SomeFunction might implement some interface or derive from a common base class. If so, you can catch the return value as that type and go from there. Else, use reflection to call ClearNum via a dynamic method invocation.
Josh
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Thanks so much, It never occurred to me that I could use methods from the common base class once a new class was derived from it - that was a big help!
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I have 2 questions regarding array manipulation:
1) which is the best way to reset an array if i initially declare as:
private byte[] array1 = new byte[0];
2) how to insert elements into array at a specified index e.g:
initial array = [1,2,3,4,5]
new array = [1,2,7,8,3,4,5]
Ragards,
Donkaiser
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You can't insert elements into an array. It is immutable. Try an ArrayList instead. Once you've finished manipulating it, you can convert it back to an array if you want.
Kevin
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so how do I convert my array into a list? and backward?
Thx
Donkaiser
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ArrayList has a ToArray() method, and your array can be added one by one to a new ArrayList when you create it, or using the AddRange method
Current blacklist
svmilky - Extremely rude | FeRtoll - Rude personal emails | ironstrike1 - Rude & Obnoxious behaviour
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ArrayList list = new ArrayList( myArray );
int[] ia = list.ToArray( typeof(int) ) as int[];
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while reconverting back to array of bytes i got an InvalidCastException error message:
"At least one element in the source array could not be cast down to the destination array type."
byte[] myArr = (byte[])myList.ToArray(typeof(byte));
why can't it cast every object to the specified byte type?
Donkaiser
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There must be something in the ArrayList which is not a byte (or not able to be converted to a byte).
Josh
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You are linkely adding ints to the Arraylist, make sure you cast them to byte before adding.
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In answer to both questions, when you need to work with arrays dynamically, use collections (or in .NET2 List<> ).
The reasons
1) Collections can be cleared with a .Clear() method
2) Collections allow dynamically adding (.Add(value)) and inserting (.Insert(index,value)) new items.
Current blacklist
svmilky - Extremely rude | FeRtoll - Rude personal emails | ironstrike1 - Rude & Obnoxious behaviour
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Thank ya'll so much!
Donkaiser
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Thanks you all,
It was kinda a pain to convert to list and back to array. so what i did was to write an algorithm for it.
int[] myarr;
int index;
in val;
for (int i= myarr.length-1; i > index ; i--)
{
myarr[ i ] = myarr[i-1]; // shift everything;
}
myarr[index] = val;
Well there's always a way to get around thing.
Donkaiser
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I declared a property of type string. In one of my codes i am using the value of property and storing into a local string variable. But i am unable to use ToString(), IndexOf, ToUpper() etc methods of local string variable. Any reason, Help very urgent
thanks
san
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kumar.bs wrote: But i am unable to use ToString(), IndexOf, ToUpper() etc methods of local string variable.
What do you mean by that? You should post the relevant code so that we can see the situation in context.
Josh
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public string DisplayFormat { get, set };
string strDisplayFormat = DisplayFormat;
on strDisplayFormat variable , i could not able to use ToString(), IndexOf() methods
san
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What do you mean by saying that you can't use those methods? What actually prevents you from doing so, a compiler error? If so, what is the error message?
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Josh Smith wrote: a compiler error
I put my money on Intellisense not showing it 
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I wrote this function to handle an exception for a FileSystemWatcher, so it gets called like this:
watchSamples01.Created += new FileSystemEventHandler(MoveFileFromSharedLog1);
where watchSamples01 is my FileSystemWatcher, and MoveFileFromSharedLog1 is my event handling function.
The method looks like this:
private static void MoveFileFromSharedLog1(object sender, System.IO.FileSystemEventArgs e)
My question is how do I send an additional parameter to my method? I would like to send an integer value to the MoveFileFromSharedLog1 method. If I try to add int x after System.IO.FileSystemEventArgs e I get this error:
Error 1 No overload for 'MoveFileFromSharedLog1' matches delegate 'System.IO.FileSystemEventHandler'
How should I do this?
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You can't alter an event handling method's signature and expect the event's associated delegate to accept your method as a valid target. The method's signature must conform to the delegate's signature. What you should do is store the integer in the class which contains the method, as a field exposed as a property.
Josh
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You can't.
Simply spoken, when registering to the Created event, you tell the FileSystemWatcher to call your MoveFileFromSharedLog1 method whenever this event occurs. The registered method must have a specific signature (defined by delegate FileSystemEventHandler') cause otherwise it couldn't be called. The FileSystemWatcher would have no knowledge what to do with an additional int parameter and which value it should have.
Anyway, what should this int parameter be for?
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rick Cook
www.troschuetz.de
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I need to setup a path to write a file to, and the path changes depending which folder the file was created on. I figured it would be quick and easy to send in a int parameter and just say writePath =("c:\path\blah" + x); so if x came in as 1 it would write to the c:\path\blah1\, 2 would write to c:\path\blah2\ and so on.
As it is now I have 2 MoveFileFromsharedLog methods and the only difference is the writePath variable. Seems very wasteful, but not sure how else I could do it.
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aquacadet wrote: the path changes depending which folder the file was created on
Use the FileSystemEventArgs.FullPath property to determine in which folder a file was created.
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rick Cook
www.troschuetz.de
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