Delphi 字符串/内存流/文件的转换

Delphi

1 把字符串直接保存为文件的方法

2 将文件直接作为字符串读出的方法

3 把字符串转化为内存流的方法

4 把内存流转化为字符串的方法

代码如下：

function StringToFile(mString: string; mFileName: TFileName): Boolean;

{ 返回字符串保存到文件是否成功 }

var

vFileChar: file of Char;//通常是以行为单位，将依次写入每一行，而这里是字，则将依次写入每个字

I: Integer;

begin

{$I-}

AssignFile(vFileChar, mFileName);

Rewrite(vFileChar);

for I := 1 to Length(mString) do

Write(vFileChar, mString[I]);

CloseFile(vFileChar);

{$I+}

Result := (IOResult = 0) and (mFileName <> '');

end; { StringToFile }

function FileToString(mFileName: TFileName): string;

{ 返回从文件载入字符串 }

var

vFileChar: file of Char;

vChar: Char;

begin

Result := '';

{$I-}

AssignFile(vFileChar, mFileName);

Reset(vFileChar);

while not Eof(vFileChar) do begin

    Read(vFileChar, vChar);

    Result := Result + vChar;

end;

CloseFile(vFileChar);

{$I+}

end; { FileToString }

function StreamToString(mStream: TStream): string;

{ 将内存流转换成字符串 }

var

I: Integer;

begin

Result := '';

if not Assigned(mStream) then Exit;

SetLength(Result, mStream.Size);

for I := 0 to Pred(mStream.Size) do try

    mStream.Position := I;

    mStream.Read(Result[Succ(I)], 1);

except

    Result := '';

end;

end; { StreamToString }

function StringToStream(mString: string; mStream: TStream): Boolean;

{ 返回将字符串保存到内存流是否成功 }

var

I: Integer;

begin

Result := True;

try

    mStream.Size := 0;

    mStream.Position := 0;

    for I := 1 to Length(mString) do mStream.Write(mString[I], 1);

except

    Result := False;

end;

end; { StringToStream }