delphi 文件分割与合并

2021-02-08 17:16

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流的使用分割与合并文件的函数

技术图片技术图片
unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

//分割文件的函数
{参数 1 是要分割的文件名; 参数 2 是要风格文件的大小, 单位是 KB}
{分割后的文件名扩展名用序号替换}
function SplitFile(const FileName: string; Size: Cardinal): Boolean;
var
  fStream: TFileStream;    {原始文件}
  toStream: TMemoryStream; {分文件}
  p,i: Integer;            {p 记录当前指针位置; i 记录这是第几个分的文件}
begin
  Result := False;

  Size := Size * 1024;     {把大小的单位转换为字节}

  fStream := TFileStream.Create(FileName, fmOpenRead);
  p := 0;
  i := 0;

  toStream := TMemoryStream.Create;

  while p do
  begin
    toStream.Clear;        {清空上次数据}
    fStream.Position := p; {放好指针位置}

    if fStream.Size-p then Size := fStream.Size-p; {最后一个时, 有多少算多少}

    toStream.CopyFrom(fStream, Size); {复制}
    toStream.SaveToFile(FileName + . + IntToStr(i));        {保存}
    Inc(i);
    p := p + Size;
  end;

  fStream.Free;
  toStream.Free;
  Result := True;
end;


//合并文件, 参数是其中一个分文件名
function MergeFile(const FileName: string): Boolean;
var
  ms: TMemoryStream; {读取分文件}
  fs: TFileStream;   {合并后的文件}
  path: string;
  i: Integer;
begin
  path := ChangeFileExt(FileName,‘‘); {去掉序号扩展名}
  ShowMessage(path);
  i := 0;

  ms := TMemoryStream.Create;
  fs := TFileStream.Create(path, fmCreate);

  while FileExists(path + . + IntToStr(i)) do
  begin
    ms.LoadFromFile(path + . + IntToStr(i));
    fs.CopyFrom(ms, 0); {TFileStream 不需要 SetSize; 但如果用 TMemoryStream 就需要}
    Inc(i);
  end;

  ms.Free;
  fs.Free;
end;



//测试分割
procedure TForm1.Button1Click(Sender: TObject);
begin
  SplitFile(c:\temp\test.txt, 10);
end;

//测试合并
procedure TForm1.Button2Click(Sender: TObject);
begin
  MergeFile(c:\temp\test.txt.0);
end;

end.
View Code

TFileStream 的读写 合并文件

TFileStream 的读写 合并文件
向TFileStream中写入字符串的问题
sbuff:TString;
S1:Tfilestream;
S1.write(sbuff,length(sbuff))是乱码
S1.write(pChar(sbuff)^,length(sbuff)))是对的~

求解释
S1.write(sbuff,length(sbuff))为什么不可以
还有length(sbuff)和sizaof(sbuff)的区别

解答:
两处错误
1,一定要先为你的string变量t指定长度(分配空间).
2,串变量t并不代表它分配的内存指针.

先SETLENGTH(T,30);
再T.READBUFFER(PCHAR(T)^,30);
不能用T.READBUFFER(T,30);
向TFileStream中写入字符串的问题
sbuff:TString;
S1:Tfilestream;
S1.write(sbuff,length(sbuff))是乱码
S1.write(pChar(sbuff)^,length(sbuff)))是对的~

求解释
S1.write(sbuff,length(sbuff))为什么不可以
还有length(sbuff)和sizaof(sbuff)的区别

解答:
两处错误
1,一定要先为你的string变量t指定长度(分配空间).
2,串变量t并不代表它分配的内存指针.

先SETLENGTH(T,30);
再T.READBUFFER(PCHAR(T)^,30);

技术图片技术图片
//合并文件, 参数是合并后的文件名
function TForm1.MergeFile(const FileName: string): Boolean;
const
s1 = #13#10#13#10#13#10#13#10;
var
ms: TMemoryStream; {读取分文件}
fs: TFileStream; {合并后的文件}
path,spliteStr: string;
i: Integer;
begin
result := False;
ms := TMemoryStream.Create;
fs := TFileStream.Create(FileName, fmCreate);

try
for i := 0 to lst1.items.Count - 1 do
begin
if i = 0then
spliteStr := # + lst1.items[i] + #13#10#13#10#13#10
else
spliteStr := #13#10#13#10#13#10 + # + lst1.items[i] + #13#10#13#10#13#10;


ms.LoadFromFile(pathtemp + lst1.items[i]);
fs.Write(PChar(spliteStr)^,length(spliteStr));
fs.Seek(0,soFromEnd);
fs.CopyFrom(ms, 0)
end;
Result := true;
finally
ms.Free;
fs.Free;
end;
end;

//合并文件, 参数是合并后的文件名
function TForm1.MergeFile(const FileName: string): Boolean;
const
s1 = #13#10#13#10#13#10#13#10;
var
ms: TMemoryStream; {读取分文件}
fs: TFileStream; {合并后的文件}
path,spliteStr: string;
i: Integer;
begin
result := False;
ms := TMemoryStream.Create;
fs := TFileStream.Create(FileName, fmCreate);

try
for i := 0 to lst1.items.Count - 1 do
begin
if i = 0then
spliteStr := # + lst1.items[i] + #13#10#13#10#13#10
else
spliteStr := #13#10#13#10#13#10 + # + lst1.items[i] + #13#10#13#10#13#10;
ms.LoadFromFile(pathtemp + lst1.items[i]);
fs.Write(PChar(spliteStr)^,length(spliteStr));
fs.Seek(0,soFromEnd);
fs.CopyFrom(ms, 0)
end;
Result := true;
finally
ms.Free;
fs.Free;
end;
View Code

文件分割

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var i, WantedFragSize, RealToWrite : Integer;
 //声明两个文件流对象
 //InStream为输入源文件流对象,OutStream为输出切割文件流对象
 InStream, OutStream : TFileStream;
 S : String;
begin
if Opendialog1.Execute then
  begin
   SaveDialog1.Title := 输入你要保存的切割文件名;
   If SaveDialog1.Execute then
   begin
    WantedFragSize := StrtoInt(Edit1.Text); //定义切割块大小
    i := 0;
    //以只读的方式创建一个输入文件流对象
    InStream:=TFileStream.Create(
    OpenDialog1.FileName,fmOpenRead);
    Try
     //如果Instream流的当前指针位置不在末尾,就按照定义的块大小//来读出数据并存成文件
     while (InStream.Position do
     Begin
      s := IntToStr(I);
      while Length(s) 3 do s := 0+s;
      s := .+s; 
      //生成切割文件的扩展名,用三位数字来作为扩展名,方便组合文件
      //如果InStream所剩的块大小小于定义的块大小,则将剩下的块数//据存成文件
      If InStream.Size - InStream.Position then
       RealToWrite := InStream.Size - InStream.Position
      else
       RealToWrite := WantedFragSize;
       //创建一个输出文件流对象
       OutStream:=TFileStream.Create(SaveDialog1.FileName+s,fmCreate);
       try
        OutStream.CopyFrom(InStream,RealToWrite);
        Inc(i);
       Finally
        //释放输出文件流对象
        OutStream.Free;
        end;
       end;
      Finally
       InStream.Free;
      end;
     end;
    end;
View Code

文件切割组合

技术图片技术图片
//切割文件
procedure TForm1.Button1Click(Sender: TObject);
 var
  i, WantedFragSize, RealToWrite : Integer;
  //声明两个文件流对象
  //InStream为输入源文件流对象,OutStream为输出切割文件流对象
  InStream, OutStream : TFileStream;
  S : String;
 begin
  if Opendialog1.Execute then
  begin
   SaveDialog1.Title := 输入你要保存的切割文件名;
   If SaveDialog1.Execute then
   begin
    WantedFragSize := StrtoInt(Edit1.Text); //定义切割块大小
    i := 0;
    //以只读的方式创建一个输入文件流对象
    InStream:=TFileStream.Create(
    OpenDialog1.FileName,fmOpenRead);
    Try
     //如果Instream流的当前指针位置不在末尾,就按照定义的块大小//来读出数据并存成文件
     while (InStream.Position do
     Begin
      s := IntToStr(I);
      while Length(s) 3 do s := 0+s;
      s := .+s; 
      //生成切割文件的扩展名,用三位数字来作为扩展名,方便组合文件
      //如果InStream所剩的块大小小于定义的块大小,则将剩下的块数//据存成文件
      If InStream.Size - InStream.Position then
       RealToWrite := InStream.Size - InStream.Position
      else
       RealToWrite := WantedFragSize;
       //创建一个输出文件流对象
       OutStream:=TFileStream.Create(SaveDialog1.FileName+s,fmCreate);
       try
        OutStream.CopyFrom(InStream,RealToWrite);
        Inc(i);
       Finally
        //释放输出文件流对象
        OutStream.Free;
        end;
       end;
      Finally
       InStream.Free;
      end;
     end;
    end;
   end;
 //组合文件
procedure TForm1.Button2Click(Sender: TObject);
var
 i : Integer;
 InStream, OutStream : TFileStream;
 SourcePath, FragName, S : String;
 begin
  Opendialog1.Title := 请选择切割文件;
  if Opendialog1.Execute then
  begin
   //得到当前打开的切割文件的路径
   SourcePath := ExtractFilePath(Opendialog1.FileName);
   //得到当前打开的切割文件的文件名
   FragName := ExtractFileName(Opendialog1.FileName);
   SaveDialog1.Title := 请输入你要组合的文件名;
   If SaveDialog1.Execute then
   begin
    i := 0;
    s := IntToStr(I);
    while Length(s) 3 do s := 0+s;
     s := .+s;
     FragName := ChangeFileExt(FragName, s);
     //如果目录中有以.000为扩展名的文件存在,则创建一个输出文件流//对象
     If FileExists(SourcePath+FragName) then
     begin
      OutStream:=TFileStream.Create(Savedialog1.FileName,fmCreate);
     Try
      //按照以文件扩展名递增的方式组合文件
      While FileExists(SourcePath+FragName) do
      Begin
       InStream:=TFileStream.Create(SourcePath+FragName,fmOpenRead);
      Try
       //将输入文件流的数据写入到输出文件流中
       OutStream.CopyFrom(InStream,0);
       Inc(i);
       s := IntToStr(I);
       while Length(s) 3 do s := 0+s;
        s := .+s;
        FragName := ChangeFileExt(FragName, s);
      finally
       InStream.Free;
      end;
     end;
    finally
     OutStream.Free;
    end;
   end;
  end;
 end;
end;
View Code

 

delphi 文件分割与合并

标签:length   源文件   color   strong   style   read   ace   exist   nta   

原文地址:https://www.cnblogs.com/blogpro/p/11345168.html


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