File_ReadByte() | TFT & EPD Graphic Library 2

Syntax

File_ReadByte(), Byte

Overview

Return value

— The byte read from the open file.

Read a Single Byte from an Open File

This procedure reads a single byte from an open file. To read the n-th byte from the file, you need to call this function in a loop n-1 times before reaching the desired byte.

How it works

File_Open: Before you can use File_ReadByte(), the file must be opened with the File_Open() or File_OpenAt() function.
End of File (EOF): You can monitor the File_tEOF variable to determine if you've reached the end of the file. When File_tEOF = 1, you've reached the end of the file.
File Open Check: You can also check if a file is currently open by monitoring the File_tIsOpen variable.
When File_tIsOpen = 1, it means a file is currently open and available for reading.

Example

File_ReadByte()

Notes

If you're trying to read the n-th byte, you can use a loop to call File_ReadByte() repeatedly.
For example, to read the second byte, you would call File_ReadByte() once and then read the byte returned in the second call.
Be sure to check File_tEOF to prevent reading past the end of the file, which would result in an error.

TftSetUp(0, 0) 'Set screen

TftResetScreen(BLACK) 'Reset screen

TftSetSndFont(0,0) 'Set Font0

While File_Init() <> cErrOK : Wend 'Initialize SD Card

TftPrintSndString("Sd Initialization OK",1,0,0,1,GREEN,BLACK,0) 'Confirm Initialize SD Card

While File_Open("Open.txt") <> cErrOK : Wend 'Open file Open.txt to edit data

TftPrintSndString("Open Open.txt OK",1,0,2,1,GREEN,BLACK,0) 'Confirm Open.txt is open

bCounter = 0 'Print position counter

TftPrintSndChar(File_ReadByte(),1,bCounter,3,1,GREEN,BLACK,0) 'Print data as text

If File_EOF() = 1 Then Break 'Loop till end of file

Inc bCounter

Loop

File_Close() 'close file

TftPrintSndString("Close Open.txt OK",1,0,4,1,GREEN,BLACK,0) 'Confirm close file

File_ReadByte()

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