本文整理自网络，侵删。
unit Unit1;
interface
uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;
type TForm1 = class(TForm) Memo1: TMemo; 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); private { Private declarations } public { Public declarations } end;
var Form1: TForm1;
implementation
{$R *.dfm}
const FileName = 'c:\temp\binary.dat';var F: file;
//用无类型的方式写入一个字节procedure TForm1.Button1Click(Sender: TObject);var b: Byte;begin AssignFile(F,FileName); Rewrite(F,1); //第二个参数表示: 把 1 个字节当作一个写入单位
b := 65; BlockWrite(F,b,1); //写入; 参数2是要写入的内容; 参数3表示写入 1 次.
CloseFile(F);//落实 binary.dat 的大小: 1个字节; 内容: A (可用记事本打开)end;
//用无类型的方式读出一个字节procedure TForm1.Button2Click(Sender: TObject);var b: Byte;begin AssignFile(F,FileName); Reset(F,1); //把 1 个字节当作一个读取单位
BlockRead(F,b,1); //读取一次; 放入 b ShowMessage(Chr(b)); //A
CloseFile(F);end;
//写入更多字节procedure TForm1.Button3Click(Sender: TObject);var buffer: array[0..127] of Byte; i: Integer; //储存多个字节, 需要用数组了begin for i := Low(buffer) to High(buffer) do buffer[i] := i; //给数组赋值, 注意现在数组大小是 128
AssignFile(F,FileName); Rewrite(F,32); //规定把 32 个字节当作一个读取单位, 注意这个数字和缓冲区大小必须是倍数关系
BlockWrite(F,buffer,4); //需要写入几次呢? 128/32=4
CloseFile(F);//写成的文件肯定是128字节大小, 但用记事本可能看不了, 因为这个二进制不是文本end;
//读出procedure TForm1.Button4Click(Sender: TObject);var buffer: array[0..127] of Byte; i: Integer;begin AssignFile(F,FileName); Reset(F,4); //把 4 字节当作一个读取单位; 为了那个倍数关系, 这里一般是 1
BlockRead(F,buffer,32); //当然需要 32 次才能读完
CloseFile(F);
//怎么显示一下呢? 还是用 Memo 吧; 显示字符? 数字? 还是十六进制吧 Memo1.Clear; for i := Low(buffer) to High(buffer) do begin Memo1.Lines.Add(IntToHex(buffer[i],1)); end;(*显示结果: 0 1 2 3 ... 7D 7E 7F *)
end;
//读写 Char 与实际读写字节procedure TForm1.Button5Click(Sender: TObject);var cArr1,cArr2: array[0..4] of Char; i: Integer; num: Integer; //记录实际读写的字节数begin for i := Low(cArr1) to High(cArr1) do cArr1[i] := Chr(65+i); //填充 A B C D E
AssignFile(F,FileName); Rewrite(F,1); //建立
BlockWrite(F,cArr1,Length(cArr1),num); //参数4: num 是实际写入的字节数 ShowMessage(IntToStr(num)); //5
Reset(F,1); //重新打开
BlockRead(F,cArr2,Length(cArr2),num); //参数5: num 是实际读出的字节数 ShowMessage(IntToStr(num)); //5
ShowMessage(cArr2); //ABCDE
CloseFile(F);end;
//写入长字符串, 读出其十六进制码procedure TForm1.Button6Click(Sender: TObject);var p: PChar; b: Byte;begin p := '万一的 Delphi 博客';
AssignFile(F,FileName); //关联文件名 Rewrite(F,1); //创建并打开 BlockWrite(F,p,Length(p)); //写入
FileMode := fmOpenRead; //这时可以设文件为只读 Reset(F,1); //为读取打开
Memo1.Clear; while not Eof(F) do begin BlockRead(F,b,1); Memo1.Text := Memo1.Text + IntToHex(b,2) + ' '; end; //显示结果: 70 F0 45 00 08 F7 12 00 A6 FB 43 00 A0 1A E5 00 FF C5
CloseFile(F);end;
//复制个文件procedure TForm1.Button7Click(Sender: TObject);var FromF,ToF: file; NumRead,NumWritten: Integer; Buffer: array[1..2048] of Byte;begin AssignFile(FromF, 'c:\temp\test1.dat'); //假定有这个文件 Reset(FromF, 1); AssignFile(ToF, 'c:\temp\test2.dat'); Rewrite(ToF, 1);
repeat BlockRead(FromF, Buffer, SizeOf(Buffer), NumRead); BlockWrite(ToF, Buffer, NumRead, NumWritten); until (NumRead = 0) or (NumWritten <> NumRead); { NumRead=0 表示读完了; NumWritten <> NumRead 表示磁盘空间不够了 }
CloseFile(FromF); CloseFile(ToF);end;
end.
来源：https://www.cnblogs.com/del/archive/2007/12/20/1007420.html 相关阅读 >>
更多相关阅读请进入《Delphi》频道 >>
