測試字串讀取類: TStringReader

TStringReader 比 TStringWriter 的方法少得多, 分別可按: 字元、行或全部讀取;

讀取字元時得到的是字元編碼, 全部或按行讀取得到是字串, 也可讀取到字元數組.

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls;type  TForm1 = class(TForm)    Button1: TButton;    Button2: TButton;    Button3: TButton;    Button4: TButton;    Button5: TButton;    Button6: TButton;    Button7: TButton;    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);    procedure Button4Click(Sender: TObject);    procedure Button5Click(Sender: TObject);    procedure Button6Click(Sender: TObject);    procedure Button7Click(Sender: TObject);  end;var  Form1: TForm1;implementation{$R *.dfm}// TStringReader.Read 是按字元讀取, 返回字元編碼procedure TForm1.Button1Click(Sender: TObject);var  Reader: TStringReader;  i: Integer;begin  Reader := TStringReader.Create('ABCDEFGHIJKLMNOPQRSTUVWXYZ');  {讀取}  i := Reader.Read;  ShowMessageFmt('%d : %s', [i, Chr(i)]); {65 : A}  {繼續讀取}  i := Reader.Read;  ShowMessageFmt('%d : %s', [i, Chr(i)]); {66 : B}  {將要讀取的}  i := Reader.Peek;  ShowMessageFmt('%d : %s', [i, Chr(i)]); {67 : C}  Reader.Free;end;//試試中文procedure TForm1.Button2Click(Sender: TObject);var  Reader: TStringReader;  i: Integer;begin  Reader := TStringReader.Create('萬一的 Delphi 部落格');  {讀取}  i := Reader.Read;  ShowMessageFmt('%d : %s', [i, Chr(i)]); {19975 : 萬}  {繼續讀取}  i := Reader.Read;  ShowMessageFmt('%d : %s', [i, Chr(i)]); {19968 : 一}  {將要讀取的}  i := Reader.Peek;  ShowMessageFmt('%d : %s', [i, Chr(i)]); {30340 : 的}  Reader.Free;end;//讀取一行procedure TForm1.Button3Click(Sender: TObject);var  Reader: TStringReader;begin  Reader := TStringReader.Create('123' + sLineBreak + 'abc' + sLineBreak + 'xyz');  ShowMessage(Reader.ReadLine); {123}  ShowMessage(Reader.ReadLine); {abc}  ShowMessage(Reader.ReadLine); {xyz}  Reader.Free;end;//一次讀取全部procedure TForm1.Button4Click(Sender: TObject);var  Reader: TStringReader;begin  Reader := TStringReader.Create('123' + sLineBreak + 'abc' + sLineBreak + 'xyz');  ShowMessage(Reader.ReadToEnd); {123 / abc / xyz}  Reader.Free;end;//按字元讀取全部procedure TForm1.Button5Click(Sender: TObject);var  Reader: TStringReader;  str: string;begin  Reader := TStringReader.Create('123' + sLineBreak + 'abc' + sLineBreak + 'xyz');  while Reader.Peek > 0 do str := str + Chr(Reader.Read);  ShowMessage(str); {123 / abc / xyz}  Reader.Free;end;//按行讀取全部procedure TForm1.Button6Click(Sender: TObject);var  Reader: TStringReader;  str: string;begin  Reader := TStringReader.Create('123' + sLineBreak + 'abc' + sLineBreak + 'xyz');  while Reader.Peek > 0 do str := str + Reader.ReadLine;  ShowMessage(str); {123abcxyz}  Reader.Free;end;//讀取到字元數組procedure TForm1.Button7Click(Sender: TObject);var  Reader: TStringReader;  buf: TCharArray;begin  Reader := TStringReader.Create('ABCDEFGHIJKLMNOPQRSTUVWXYZ');  SetLength(buf, 3);  Reader.ReadBlock(buf, 0, Length(buf));  ShowMessageFmt('%s%s%s', [buf[0], buf[1], buf[2]]); {ABC}  Reader.Free;end;end.