将RTF文本从数据库加载到TRichEdit [英] Loading RTF text from database into TRichEdit

问题描述

我目前正在将我们的软件解决方案从Delphi 7迁移到2010年。大部分变化很简单，只剩下少量障碍了。

在表单上，​​我们使用TRichEdit，它显示了从MSSQL数据库中的blob字段中获取的rtf文本。这是它在Delphi 7中的工作原理：

  //使用TADOQuery从Blob字段获取RTF文本
 rtfStream：= sql.CreateBlobStream（sql.FieldByName（'rtftext'），BmRead）作为TMemoryStream; 
 
 //加载到TRichEdit 
 RichEdit.PlainText：= False; 
 RichEdit.Lines.LoadFromStream（rtfStream）; 
  

这将显示TRichEdit组件中的RTF，但Delphi 2010中的相同代码显示RTF作为每个字符之间的标签的纯文本。我认为这与从Ansi到Unicode的变化有很大关系，但是我没有任何运气纠正这个问题。

非常感谢谢谢

解决方案

好吧，我想出来。

要加载rtf文本：

  //从数据库中获取数据为AnsiString 
 rtfString： = sql.FieldByName（'rtftext'）。AsAnsiString; 
 
 //将字符串写入流
 stream：= TMemoryStream.Create; 
 stream.Clear; 
 stream.Write（PAnsiChar（rtfString）^，Length（rtfString））; 
 stream.Position：= 0; 
 
 //将流加载到RichEdit 
 RichEdit.PlainText：= False; 
 RichEdit.Lines.LoadFromStream（stream）; 
 
 stream.Free; 
  

为了保存rtf文本：

  //保存到流
 stream：= TMemoryStream.Create; 
 stream.Clear; 
 
 RichEdit.Lines.SaveToStream（stream）; 
 stream.Position：= 0; 
 
 //从流中读取到一个AnsiString（rtfString）
 if（stream.Size> 0）然后开始
 SetLength（rtfString，stream.Size）; 
 if（stream.Read（rtfString [1]，stream.Size）< = 0）then 
 raise EStreamError.CreateFmt（'End of stream reached with％d bytes left to read。'， stream.Size]）; 
结束
 
 stream.Free; 
 
 //保存到数据库
 sql.FieldByName（'rtftext'）。AsAnsiString：= rtfString; 
  

这让我太久了，找出:)我想我已经学了一件事如果Delphi 2010出现问题，它通常与unicode相关;）

I am currently in the process of migrating our software solution from Delphi 7 to 2010. Mostly the changes have been simple and there are only a small amount of hurdles left to go.

On a form we use a TRichEdit which displayed rtf text grabbed from a blob field in a MSSQL db. This is how it worked in Delphi 7:

//Get RTF text from Blob field using TADOQuery
rtfStream := sql.CreateBlobStream(sql.FieldByName('rtftext'), BmRead) as TMemoryStream;

//Load into TRichEdit
RichEdit.PlainText := False;
RichEdit.Lines.LoadFromStream(rtfStream);

This would display the RTF as expected in the TRichEdit component, but the same code in Delphi 2010 displays the RTF as plain text with tabs between each character. I assume this has a lot to do with the change from Ansi to Unicode, but I haven't had any luck rectifying the problem.

Any help getting this to work would be much appreciated. Thanks

解决方案

Okay I figured it out.

For loading the rtf text:

//Get the data from the database as AnsiString
rtfString := sql.FieldByName('rtftext').AsAnsiString;

//Write the string into a stream
stream := TMemoryStream.Create;
stream.Clear;
stream.Write(PAnsiChar(rtfString)^, Length(rtfString));
stream.Position := 0;

//Load the stream into the RichEdit
RichEdit.PlainText := False;
RichEdit.Lines.LoadFromStream(stream);

stream.Free;

For saving the rtf text:

//Save to stream
stream := TMemoryStream.Create;
stream.Clear;

RichEdit.Lines.SaveToStream(stream);
stream.Position := 0;

//Read from the stream into an AnsiString (rtfString)
if (stream.Size > 0) then begin
    SetLength(rtfString, stream.Size);
    if (stream.Read(rtfString[1], stream.Size) <= 0) then
        raise EStreamError.CreateFmt('End of stream reached with %d bytes left to read.', [stream.Size]);
end;

stream.Free;

//Save to database
sql.FieldByName('rtftext').AsAnsiString := rtfString;

This took me way too long to figure out :) I guess I have learned one thing though... if something goes wrong in Delphi 2010, its usually related to unicode ;)

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