| Description |
If the current stream has not been exhausted, up to Count characters are returned.
The stream position is updated accordingly.
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| | Notes | You must set the length of the target Char array, and it must have sufficient capacity to hold the returned characters.
Compare with the more flexible Read method, where a block of stream characters can be read into an array at a specific array position.
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| Microsoft MSDN Links |
System.IO
System.IO.BinaryReader
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| Reading blocks of bytes |
// Full Unit code.
// -------------------------------------------------------------
// Create a new WinForm application, double click the form to
// create an OnLoad event, and then replace the WinForm unit
// with this text.
unit WinForm;
interface
uses
System.Drawing, System.Collections, System.ComponentModel,
System.Windows.Forms, System.Data;
type
TWinForm = class(System.Windows.Forms.Form)
\{REGION 'Designer Managed Code'\} // Note that REGION and ENREGION should be prefixed by a dollar sign
strict private
///
/// Required designer variable.
///
Components: System.ComponentModel.Container;
///
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
///
procedure InitializeComponent;
procedure TWinForm_Load(sender: System.Object; e: System.EventArgs);
{ENDREGION}
strict protected
///
/// Clean up any resources being used.
///
procedure Dispose(Disposing: Boolean); override;
private
{ Private Declarations }
public
constructor Create;
end;
[assembly: RuntimeRequiredAttribute(TypeOf(TWinForm))]
implementation
\{REGION 'Windows Form Designer generated code'\}
///
/// Required method for Designer support -- do not modify
/// the contents of this method with the code editor.
///
procedure TWinForm.InitializeComponent;
begin
//
// TWinForm
//
Self.AutoScaleBaseSize := System.Drawing.Size.Create(5, 13);
Self.ClientSize := System.Drawing.Size.Create(292, 266);
Self.Name := 'TWinForm';
Self.Text := 'WinForm';
Include(Self.Load, Self.TWinForm_Load);
end;
{ENDREGION}
procedure TWinForm.Dispose(Disposing: Boolean);
begin
if Disposing then
begin
if Components <> nil then
Components.Dispose();
end;
inherited Dispose(Disposing);
end;
constructor TWinForm.Create;
begin
inherited Create;
//
// Required for Windows Form Designer support
//
InitializeComponent;
//
// TODO: Add any constructor code after InitializeComponent call
//
end;
procedure TWinForm.TWinForm_Load(sender: System.Object; e: System.EventArgs);
program Project1;
{$APPTYPE CONSOLE}
uses
System.IO;
var
MyFileStream : System.IO.FileStream;
MyFileWriter : System.IO.BinaryWriter;
MyFileReader : System.IO.BinaryReader;
MyCharArray : Array of Char;
Index : Integer;
begin
// Create and open our binary file as a stream
MyFileStream := System.IO.File.Open('C:DelphiBasics.txt',
System.IO.FileMode.Create);
// Create a BinaryWriter to allow writing to this file
MyFileWriter := System.IO.BinaryWriter.Create(MyFileStream);
// Write to the file
MyFileWriter.Write('A');
MyFileWriter.Write('B');
MyFileWriter.Write('C');
MyFileWriter.Write(49); // Chr(49) = '1'
MyFileWriter.Write(50); // Chr(50) = '2'
MyFileWriter.Write(51); // Chr(51) = '3'
MyFileWriter.Write(52); // Chr(52) = '4'
// Close the writer and the stream
MyFileWriter.Close;
MyFileStream.Close;
// Reopen the stream for reading
MyFileStream := System.IO.File.Open('C:DelphiBasics.txt',
System.IO.FileMode.Open);
// Create a BinaryReader to allow the file to be read back
MyFileReader := System.IO.BinaryReader.Create(MyFileStream);
// Declare our array to hold the returned data
SetLength(MyCharArray, 10);
// Get the whole file contents into our array
// Note that we do not necessarily get the same number of
// characters that we request : we actually get 7 here
MyCharArray := MyFileReader.ReadChars(10);
// Display our array contents
Console.WriteLine(MyCharArray);
// Close the reader and the stream
MyFileReader.Close;
MyFileStream.Close;
Console.Readline;
end.
end. | | Hide full unit code | ABC1234
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