| Description |
The Reset procedure opens a file given by FileHandle for read, write or read and write access.
You must use AssignFile to assign a file to the FileHandle before using Reset.
Use Write or WriteLn to write to the file after this Reset is executed.
Version 1
Is used for text files. They can only be read after opening with Reset.
Version 2
Is for binary files.
Before using Reset, you must set FileMode to one of the following:
| fmOpenRead | : Read only |
| fmOpenWrite | : Write only |
| fmOpenReadWrite | : Read and write |
The optional RecordSize value is used to override the default 128 byte record size for binary (untyped) files. For such files, only BlockRead and BlockWrite can be used.
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| Related commands |
| Append |
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Open a text file to allow appending of text to the end |
| AssignFile |
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Assigns a file handle to a binary or text file |
| CloseFile |
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Closes an open file |
| File |
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Defines a typed or untyped file |
| ReWrite |
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Open a text or binary file for write access |
| TextFile |
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Declares a file type for storing lines of text |
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| Example code : Writing and reading lines of text to/from a text file |
// Full Unit code.
// -----------------------------------------------------------
// You must store this code in a unit called Unit1 with a form
// called Form1 that has an OnCreate event called FormCreate.
unit Unit1;
interface
uses
// The System unit does not need to be defined
SysUtils,
Forms, Dialogs;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm} // Include form definitions
procedure TForm1.FormCreate(Sender: TObject);
var
myFile : TextFile;
text : string;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write a couple of well known words to this file
WriteLn(myFile, 'Hello');
WriteLn(myFile, 'World');
// Close the file
CloseFile(myFile);
// Reopen the file in read only mode
FileMode := fmOpenRead;
Reset(myFile);
// Display the file contents
while not Eof(myFile) do
begin
ReadLn(myFile, text);
ShowMessage(text);
end;
// Close the file for the last time
CloseFile(myFile);
end;
end.
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| Hide full unit code |
Hello
World
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