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DavidCrow wrote: Previously, my CMyEventHandler class was derived from, among others, IWMPEvents, and I thought I had the appropriate IWMPEvents entry in the BEGIN_COM_MAP() macro. So I don't understand what the Media Player server could have been asking for that I was not providing/exposing.
Yep, but as I understand it you got a compiler error at that time and not the runtime error that says the server cannot find the IWMPEvents interface in your client.
DavidCrow wrote: They were added by the ATL Object Wizard.
Okay. You probably used the wizard that is used for creating COM servers. But that's a minor problem, it just made me unsure of what you were trying to do. Never mind.
DavidCrow wrote: How does moving the IWMPEvents interface to CMyEventSink differ from having it in CMyEventHandler?
In your case it doesn't really make a difference in practice.
However, I consider the nested class a more versatile solution or design pattern. One major benefit is to avoid circular references.
Consider COM server A that creates another COM server B. A is created by the client C. B exposes a source interface, e.g. a connection point, for which A implements an event sink and register itself for receiving COM events from B. When B requests the interface for the event sink it will increment the reference of A according to COM rules.
The problem is that when C wants to destroy A by releasing its last reference, the A reference counter will not reach zero as B still holds a reference to it. This will force a kind of catch 22 situation where neither A nor B will get their last reference released.
The root cause is that both C and B uses the same object for reference counting in A. One solution is to create another object, like a nested class inside A, that serves as event sink.
My point is that if you master this way of creating an event sink, you'll probably never have to do it in another way.
I also consider it more clean from a design point of view.
"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown
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Hi,
I have looked everywhere on the web a good tutorial for sample code that creates a System Tray icon for an application and when you right click on the system tray icon it will display a context menu with a list of options. Please could someone help me create a the basics of it.
Thank you.Andrew McIntyre
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| That link is no use to me. I only has links to magazines. Andrew McIntyre
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Sorry about that. I have not visited that site for a long time.
Maybe you need to write your own code for that.
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In fact, Paul DiLascia's sample program is available from Microsoft's website:
http://www.microsoft.com/msj/0299/c/c0299.aspx[^]
Click on the link at "code for this article", you will be able to download a ready to use code for tray icon manipulations. The second question in that article is about tray icons.
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See here. The article itself is not about this topic, but the code is downloadable and easy to understand."One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Man who follows car will be exhausted." - Confucius
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| Quite a few articles here on CodeProject; always the best place to search first. txtspeak is the realm of 9 year old children, not developers. Christian Graus
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I was reading on the microsoft website how to encode a string of char [], this is my output:
#include "stdafx.h"
#include <conio.h>
#include <iostream>
#include <string>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
char EncString[] = "My name is Branden";
char key = 128;
cout << "Your string of text: " << EncString << endl;
for ( int i = 0 ; i < strlen(EncString) ; i++ )
EncString[i] = EncString[i] ^ key;
cout << "Encoded text : " << EncString << endl;
for ( int i = 0 ; i < strlen(EncString) ; i++ )
EncString[i] = EncString[i] ^ key;
cout << "Decoded text : " << EncString << endl;
_getch();
return 0;
}
I dont understand what '^' is, I know i have key declared as 128bits i guess, but the ^ operator throws me off. What is ^ specific function?
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Herboren wrote: I dont understand what '^' is,
It's bitwise XOR operator
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this is what i understand, it compares each bit of its first operand to the corresponding bit of the second operand.
but when I change the value of "key" from say 128 to 8, it comes out a totally different encoded string, why is that?
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Encode 0x20 using Key 00000001:
0x20 = 0010 0000 XOR 00000001 = 00100001
to deccode do the XOR again:
00100001 XOR 00000001 = 0010 0000
But change key from 00000001 to 10000000 and you get:
0x20 = 0010 0000 XOR 10000000 = 10100000
to decode do the XOR again:
10100000 XOR 10000000 = 0010 0000
So a different Key gives a different encoded value but decodes using the same key to the original value.
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So its just matching The string to a mixed ascii string and saving the key sequence for remembering it later.
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Okay well i have another program that I just made and im still trying to figure out how this progam is getting the binary conversion:
#include "stdafx.h"
#include <conio.h>
using namespace std;
void Show_Binary(unsigned int u);
int _tmain(int argc, _TCHAR* argv[])
{
int i;
cout << "Enter a number between 1 - 255: "; cin >> i;
cout << "Your number in BINARY is : "; Show_Binary(i);
_getch();
return 0;
}
void Show_Binary(unsigned int u)
{
int t;
for ( t = 128; t > 0; t = t / 2 )
if (u & t) cout << "1 "; else
cout << "0 ";
cout << endl;
}
as u can see I have been trying to figure it out myself in the comment below, but the 't = t / 2' is throwing me off, I understand the t = 128, using the binary scale: 128 64 32 16 8 4 2 1, but how its checking it, is whats confusing me, I understand the if statements but when if just sits there with the 'if ( u & t)' im asking myself "wtf is if asking, is it equal to, is it less than more than dammit 'if' tell me what your evil plot is!" lol
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It is trying to extract each bit out and show it on screen. In the language, the number 0 is understood as 'false', the number 1 is understood as 'true'. Hope you get the idea.
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Ok so its extracting the bit itself, like 8bits equals =1byte sort of thing and each bit within those 8bits dont match it comes out as false otherwise true and its not matching the actual value that the user input
True>
User input: 2
Binary: 0000010
Match: 00000010
128 64 32 16 8 4 2 1
False False False False False False True False
correct?
False>
128 64 32 16 8 4 2 1
2
incorrectmodified on Thursday, March 11, 2010 3:54 PM
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What a mess!
The key is for you to remember so you can decode an encoded text to get the original text. Different keys will produce different encoded text. For somebody who don't know the key you used to encode a string, he will have a hard time (not very hard for your algorithm, though) to decode to get the original text.
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So if this were a GUI app asking for a certain to decode txt, he/she would need that key, I see thats actually really cool, I like how that works, arent there popular programs like that required user specific keys to decode the text?
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'Matching' is a bit of a vague term to use, it's XORing each character of the string in turn with the key
for ( int i = 0 ; i < strlen(EncString) ; i++ )
EncString[i] = EncString[i] ^ key;
and replacing the character EncString[i]with the encoded character EncString[i] ^ key.
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for ( int i = 0 ; i < strlen(EncString) ; i++ )
EncString[i] = EncString[i] ^ key;
I gotcha this is how I knew
char EncString[] = "My String of text";
Your string of text: My String of text
Encoded text : ═∙á╙⌠≥Θετá∩µá⌠σ°⌠
Decoded text : My String of text
char EncString[] = "My ";
Your string of text: My
Encoded text : ═∙á
Decoded text : My
'═∙á' match as long as the key bit stayed the same unless I changed its value
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| I am new in cryptography. I found that .NET has good support for cryptography. Are there similar Win32 API or MFC classes I can use in native C++ code? Best,
Jun
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| MSDN has information here[^] on support for cryptography. txtspeak is the realm of 9 year old children, not developers. Christian Graus
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