File_ChDirUp() | TFT & EPD Graphic Library 2

Syntax

File_ChDirUp(), Bit

Overview

Return value

— A single bit indicating success or failure.

1: Success — the directory has been changed to the parent directory.

0: Failure — the directory change was unsuccessful (e.g., if you're already at the root directory).

Change to Parent Directory

The File_ChDirUp() command allows you to change the current working directory to the parent directory of the current directory.
This is useful for navigating upwards through the directory structure on the SD card.

Example

File_ChDirUp()

Purpose:

To move the current working directory up one level to the parent directory.
After calling this command, all subsequent file operations will be performed within the parent directory of the current directory.

Notes

Before calling File_ChDirUp(), make sure to close any open files using File_Close() to ensure the proper functioning of the command.
If the current directory is the root directory (i.e., the topmost directory), you cannot go further up, and the command will fail, returning 0.
This function is often used for navigating back up the directory tree when browsing through nested folders.

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

DisplayFolderFile(28) 'Call file/folder list Proc, set display row 28

If File_ChDir("Fol1") = 1 Then 'Change current folder to Fol1

TftPrintSndString("Change to Fol1 OK",1,0,1,1,GREEN,BLACK,0) 'Confirm change folder To Fol1

DisplayFolderFile(20) 'Call file/folder list Proc, Set display row 20

Else

TftPrintSndString("Change to Fol1 Fail",1,0,1,1,GREEN,BLACK,0) 'Folder change fail

EndIf

If File_ChDirUp() = 1 Then 'Return to parent directory

TftPrintSndString("Change to Parent OK",1,0,2,1,GREEN,BLACK,0) 'Confirm change to parent folder

DisplayFolderFile(12) 'Call file/folder list Proc, Set display row 12

Else

TftPrintSndString("Change to Parent Fail",1,0,2,1,GREEN,BLACK,0) 'Folder change to parent fail

EndIf

End

Proc DisplayFolderFile(wY As Word)

bCounter = wY

File_ListReset() 'Reset file/folder counter

Clear sString

sString = File_ListDir() 'Loop through folder names

If sString = 0 Then Break 'Break if end of list

TftPrintSndString(sString,1,0,bCounter,1,GREEN,BLACK,0) 'Print folder name

Dec bCounter 'Move to next print line

Loop

bCounter = wY 'Vertical print counter

File_ListReset() 'Reset file/folder counter

Do 'Loop through file names

Clear sString

sString = File_ListFile()

If sString = 0 Then Break 'Break if end of list

TftPrintSndString(sString,1,20,bCounter,1,WHITE,BLACK,0) 'Print folder name

Dec bCounter 'Move to next print line

Loop

EndProc

File_ChDirUp()

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