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28 lines
1.8 KiB
Markdown
28 lines
1.8 KiB
Markdown
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In QB64 **handles** are created and used by various statements and functions to reference screen surfaces, images, sounds, fonts and IP users.
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## Syntax
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> **handle& =** _NEWIMAGE(800, 600, 32)
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> _FREEIMAGE **handle&**
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## Usage
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* [SCREEN](SCREEN) and image handles in use cannot be freed without error! Change screens or fonts before freeing the handle from memory!
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* The actual value of the handle is only important if it fails to return a value in the range specified. **A bad return value may create errors!**
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## Handle Functions
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* Image: [_NEWIMAGE](_NEWIMAGE) creates a screen surface, [_LOADIMAGE](_LOADIMAGE) holds a file image and [_FREEIMAGE](_FREEIMAGE) releases valid handles from memory.
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- Valid [LONG](LONG) handle returns are less than -1. Failed [_LOADIMAGE](_LOADIMAGE) handle values of -1, zero or positive values are invalid.
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* TCP/IP: [_OPENHOST](_OPENHOST), [_OPENCLIENT](_OPENCLIENT) and [_OPENCONNECTION](_OPENCONNECTION) open access and [CLOSE](CLOSE) frees negative handle values from memory.
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* Memory: [_MEM (function)](_MEM-(function)) and [_MEMNEW](_MEMNEW) create memory storage areas and [_MEMFREE](_MEMFREE) MUST release those areas for other uses.
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* Sound: [_SNDOPEN](_SNDOPEN) opens a sound file and [_SNDCLOSE](_SNDCLOSE) closes the file and releases valid handles above zero from memory.
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* Fonts: [_LOADFONT](_LOADFONT) loads a font file and [_FREEFONT](_FREEFONT) releases valid handle values above zero from memory.
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* Event: [_FREETIMER](_FREETIMER) finds a free [TIMER](TIMER) event [INTEGER](INTEGER) value which is freed by [TIMER (statement)](TIMER-(statement)) FREE.
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* Files: [FREEFILE](FREEFILE) finds a free file [INTEGER](INTEGER) value which is used in [OPEN](OPEN) statements and file functions and is freed by [CLOSE](CLOSE)
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## See Also
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* [_SOURCE](_SOURCE), [_DEST](_DEST)
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