LPARAM with WM_CHAR

This is a discussion on LPARAM with WM_CHAR within the Windows Programming forums, part of the Platform Specific Boards category; Ok, I've been looking at a tutorial for keyboard input... and at the end, it says this: Code: This following ...

  1. #1
    Carnivore ('-'v) Hunter2's Avatar
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    LPARAM with WM_CHAR

    Ok, I've been looking at a tutorial for keyboard input... and at the end, it says this:

    Code:
    This following is the BIT values breakdown of the 32-bit LPARAM -- Be sure to check
    	MSDN for any changes
    
    	0 - 15	Specifies the repeat count for the current message. The value is the number of
    			times the keystroke is auto-repeated as a result of the user holding down the key
    
    	16 - 23	Specifies the scan code. The value depends on the original equipment
    			manufacturer (OEM)
    			
    	   24	Specifies whether the key is an extended key, such as the right-hand alt and 
    			ctrl keys that appear on an enhanced 101-key or 102-key keyboard. The value is 1 
    			if it is an extended key otherwise it's 0
    			
    	25 - 28 Reserved
    
    	   29	The context code. The value is 1 if the alt key is held down while 
    			the key is pressed otherwise it's 0
    			
    	   30	The previous key state. The value is 1 if the key is down
    			before the message is sent, or it is 0 if the key is up
    
    	   31	The transition state. The value is 1 if the key is being released, 
    			or it's 0 if the key is being pressed
    The only thing I really need from the LPARAM is the last part, about the key being pressed/released, but how do I get its value? (I mean, do I typecast to a bool or something, or use some macro?)
    Just Google It. √

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  2. #2
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    all you need to look at is WPARAM as it contains the key code of the character that was pressed.

    Code:
    if(wParam == 'A')
    {
       // A/a was pressed
    }
    hope this helps
    U.
    Quidquid latine dictum sit, altum sonatur.
    Whatever is said in Latin sounds profound.

  3. #3
    Carnivore ('-'v) Hunter2's Avatar
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    I got that far, but I want to be able to figure out when the key is released. I actually started out trying to use WM_KEYDOWN/KEYUP, but I couldn't figure out how the virtual-key codes worked. Then I looked at WM_CHAR and it has that flag thingee telling if the message was generated because the key was being pressed or released... I tried doing this:

    Code:
    bool* test = (bool*)&lParam;
    if(test[31] == 0)
           (...)
    It didn't bomb, but when the message was generated, test[31] was always 0.

    Do you know how I might find out what key it is when a WM_KEYDOWN message pops up?
    Just Google It. √

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  4. #4
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    yeah.. for keys a-z and A-Z they are the same as the actual ascii for uppercase chars.

    so when you can the WM_KEYUP/DOWN messages... test for 'A', 'B', 'C' etc.... all the other keys have a VK_* constant ...that should get you going...

    good luck!
    U.
    Quidquid latine dictum sit, altum sonatur.
    Whatever is said in Latin sounds profound.

  5. #5
    Carnivore ('-'v) Hunter2's Avatar
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    Ahhhh, it has to be uppercase eh? That would explain a lot. I kept trying lowercase
    Just Google It. √

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  6. #6
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    your welcome!


    manners will get you more help in the future mate.
    Quidquid latine dictum sit, altum sonatur.
    Whatever is said in Latin sounds profound.

  7. #7
    Carnivore ('-'v) Hunter2's Avatar
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    Oh, I forgot - thanks! (I thought I usually say thanks anyways?... oh well.)
    Just Google It. √

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  8. #8
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    no probs
    Quidquid latine dictum sit, altum sonatur.
    Whatever is said in Latin sounds profound.

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