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}// 其 WriteLine、Write 各有写入多种数据类型的重载procedure TForm1.Button1Click(Sender: TObject);var  Writer: TStringWriter;begin  Writer := TStringWriter.Create;  Writer.WriteLine('aaa');  Writer.WriteLine('bbb');  ShowMessage(Writer.ToString);  Writer.Free;  Writer := TStringWriter.Create;  Writer.Write('aaa');  Writer.Write('bbb');  Writer.WriteLine;  Writer.Write('ccc');  ShowMessage(Writer.ToString);  Writer.Free;end;//写入 Boolean、Charprocedure TForm1.Button2Click(Sender: TObject);const  b1: Boolean = True;  b2: Boolean = False;  c1: Char = 'A';  c2: Char = 'B';var  Writer: TStringWriter;begin  Writer := TStringWriter.Create;  Writer.WriteLine(b1);  Writer.WriteLine(b2);  Writer.WriteLine(c1);  Writer.WriteLine(c2);  ShowMessage(Writer.ToString);  Writer.Free;end;//写入整数和浮点数procedure TForm1.Button3Click(Sender: TObject);const  n1 = 1;  n2 = -1;  f = 3.14;var  Writer: TStringWriter;begin  Writer := TStringWriter.Create;  Writer.WriteLine(n1);  Writer.WriteLine(n2);  Writer.WriteLine(f);  ShowMessage(Writer.ToString);  Writer.Free;end;//格式化写入procedure TForm1.Button4Click(Sender: TObject);var  Writer: TStringWriter;begin  Writer := TStringWriter.Create;  Writer.Write('%d + %d = %d', [1,2,3]);  ShowMessage(Writer.ToString);  Writer.Free;end;//写入字符数组procedure TForm1.Button5Click(Sender: TObject);var  Writer: TStringWriter;  cs: TCharArray;  i: Integer;begin  SetLength(cs, 26);  for i := 0 to Length(cs) - 1 do cs[i] := Chr(65+i);  Writer := TStringWriter.Create;  Writer.WriteLine(cs);  Writer.WriteLine(cs, 1, 3);  ShowMessage(Writer.ToString);  Writer.Free;end;//写入对象(类名)procedure TForm1.Button6Click(Sender: TObject);var  Writer: TStringWriter;begin  Writer := TStringWriter.Create;  Writer.WriteLine(Self);  Writer.WriteLine(Sender);  ShowMessage(Writer.ToString);  Writer.Free;end;//从 TStringBuilder 建立procedure TForm1.Button7Click(Sender: TObject);var  Writer: TStringWriter;  sb: TStringBuilder;begin  sb := TStringBuilder.Create('ABC');  Writer := TStringWriter.Create(sb);  Writer.WriteLine;  Writer.Write(123);  ShowMessage(Writer.ToString);  sb.Free;  Writer.Free;end;end.