RichViewEdit特殊操作
RichviewEdit 图文保存操作 首先要转换成stream后才能对RichviewEdit进行正确的读和写 function SaveRVFToField(rv: TCustomRichView; tbl: TTable; const FieldName: String): Boolean; var Stream: TStream; begin Stream :=TMemoryStream.Create; try Result := rv.SaveRVFToStream(Stream, False); Stream.Position := 0; TBlobField(tbl.FieldByName(FieldName)).LoadFromStream(Stream); finally Stream.Free; end; end; function LoadRVFFromField(rv: TCustomRichView; tbl: TTable; const FieldName: String): Boolean; var Stream: TStream; begin Stream := TMemoryStream.Create; try TBlobField(tbl.FieldByName(FieldName)).SaveToStream(Stream); Stream.Position := 0; Result := rv.LoadRVFFromStream(Stream); finally Stream.Free; end; rv.Format; end; 以上的两个函数是把RichviewEdit的内容保存到数据库里面的做法。但是， RichViewEdit的图片内容保存到数据库后，有些图片保存的时候看起来是正常的，但是再从数据库里面读出来就看不到图片了，但是这种状况并不是每张图片都会发生，有些图片放进去数据库后又能正常显示，百思不得其解！ 后来在RichViewEdit的RVFOptions——rvfoSaveBinary设置成False，这样从数据库里面读取出来的图片就都能正常显示了。 让 RichviewEdit 内容转换成图片 procedure TSendDataFrm.btnR2BClick; const VERYLARGEVALUE = $FFFFFFF; var iWidth, iHeight: integer; Canvas: TMetafileCanvas; bmp: TBitmap; wmf: TMetafile; i, j, k: integer; begin RVE.HScrollPos := 0; RVE.VScrollPos := 0; RVE.Deselect; RVE.Invalidate; k := 0; for i := 0 to RVE.LineCount - 1 do begin j := RVE.Canvas.TextWidth(RVE.GetItemTextA(i)); //+RVE.GetItemTextR(i)图片长 if j > K then k := j; end; iWidth := k; iHeight := RVE.RVData.DocumentHeight - 10; Image1.Picture.Bitmap.Width := iwidth; Image1.Picture.Bitmap.Height := iHeight; bitblt(Image1.Picture.Bitmap.Canvas.Handle, -1, -7 , RVE.Width, RVE.Height, GetWindowDC(RVE.Handle), 0, 0, SRCCOPY); image1.Refresh; 让 RichviewEdit 支持中文 ⑴ 设置RichViewEdit下面的几个属性： ① TRVRTFReaderProperties → ParaStyleMode → rvrsAddIfNeeded ② TRVRTFReaderProperties → TextStyleMode → rvrsAddIfNeeded ③ TRVRTFReaderProperties → UnicodeMode → rvruOnlyUnicode ⑵ 设置RVStyle： 双击该控件，在弹出的窗体里选定里面5个子项，然后在属性窗体里找到 Unicode属性，全部改为：True;
ichEdit的内容保存为图片
uses RichEdit; {将RichEdit1的内容保存为图片，此函数也适合于RxRichEdit，即RichEdit: TRxRichEdit} procedure RichEditToCanvas(RichEdit: TRichEdit; Canvas: TCanvas; PixelsPerInch: Integer); var ImageCanvas: TCanvas; fmt: TFormatRange; begin ImageCanvas := Canvas; with fmt do begin hdc:= ImageCanvas.Handle; hdcTarget:= hdc; rc:= Rect(0, 0, ImageCanvas.ClipRect.Right * 1440 div PixelsPerInch, ImageCanvas.ClipRect.Bottom * 1440 div PixelsPerInch); rcPage:= rc; chrg.cpMin := 0; chrg.cpMax := RichEdit.GetTextLen; end; SetBkMode(ImageCanvas.Handle, TRANSPARENT); RichEdit.Perform(EM_FORMATRANGE, 1, Integer(@fmt)); RichEdit.Perform(EM_FORMATRANGE, 0, 0); end; procedure TForm1.Button1Click(Sender: TObject); begin RichEditToCanvas(RichEdit1, Image1.Canvas, Self.PixelsPerInch); Image1.Refresh; end; TRichEdit的打印预览 Rich Edit控件（我们说的是标准的Windows控件，不是一个Delphi构件）包含内置的打印特性，可以使用这个特性向打印机传送格式化的文本，或是通过程序员稍微地努力就可将它的内容绘制到任何Canvas上。 当然，标准的Delphi TRichEdit构件封装了这一特性。我们可以使用这一可能性来制作一个快速的比例缩放的打印预览，或者将Rich Text绘制到任何Delphi控件上。 将Rich Edit控件绘制到任何Canvas上，涉及使用标准Rich Edit控件消息EM_FORMATRANGE。 这个消息的lParam参数是一个指向TFormatRange纪录的指针。在将消息传递给RichEdit之前，必须填充这个记录。 TFORMATRANGE记录包含一个rich edit控件用于格式化输出它的内容到特定设备的信息。这里的 hdc —— 要渲染的设备。 HdcTarget —— 要格式化的目标设备。 rc —— 要渲染的区域。使用的测量单位是缇。缇是一种不受屏幕约束（screen-independent）的单位，以确保屏幕元素的比例在所有显示系统上都相同。一缇被定义为一英寸的1/1440。 RcPage —— 渲染设备的整个区域。使用的测量单位是缇。 chrg —— TCHARRANGE记录指定了格式化文本的范围。 这个记录通常被EM_EXGETSEL和EM_EXSETSEL消息使用，它包含两个域：cpMin和cpMax。 cpMin 是一个字符位置索引，直接位于范围内第一个字符之前。 cpMax 是一个字符位置索引，直接位于范围内最后一个字符之后。 打印一个Rich Edit控件到一个位图上用于预览 完整页代码： unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ComCtrls, ExtCtrls, RichEdit; type TForm1 = class(TForm) Button1: TButton; Button2: TButton; Image1: TImage; RichEdit1: TRichEdit; procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} function PrintRTFToBitmap(ARichEdit : TRichEdit; ABitmap : TBitmap) : Longint; var range : TFormatRange; begin FillChar(Range, SizeOf(TFormatRange), 0); // 渲染我们要测量的相同DC。 Range.hdc := ABitmap.Canvas.handle; Range.hdcTarget := ABitmap.Canvas.Handle; // 设定页。 Range.rc.left := 0; Range.rc.top := 0; Range.rc.right := ABitmap.Width * 1440 div Screen.PixelsPerInch; Range.rc.Bottom := ABitmap.Height * 1440 div Screen.PixelsPerInch; // 打印文本的缺省范围为整个文档。 Range.chrg.cpMax := -1; Range.chrg.cpMin := 0; // 格式化文本。 Result := SendMessage(ARichedit.Handle, EM_FORMATRANGE, 1, Longint(@Range)); // 释放缓冲信息。 SendMessage(ARichEdit.handle, EM_FORMATRANGE, 0,0); //Image1.Refresh; end; // 接下来的实例显示了不只是如何将Rich Edit绘制到任何Canvas上，还包括如何只绘制选择的文本范围。 function PrintToCanvas(ACanvas : TCanvas; FromChar, ToChar : integer; ARichEdit : TRichEdit; AWidth, AHeight : integer) : Longint; var Range : TFormatRange; begin FillChar(Range, SizeOf(TFormatRange), 0); Range.hdc := ACanvas.handle; Range.hdcTarget := ACanvas.Handle; Range.rc.left := 0; Range.rc.top := 0; Range.rc.right := AWidth * 1440 div Screen.PixelsPerInch; Range.rc.Bottom := AHeight * 1440 div Screen.PixelsPerInch; Range.chrg.cpMax := ToChar; Range.chrg.cpMin := FromChar; Result := SendMessage(ARichedit.Handle, EM_FORMATRANGE, 1, Longint(@Range)); SendMessage(ARichEdit.handle, EM_FORMATRANGE, 0,0); end; {use PrintRTFToBitmap function} procedure TForm1.Button1Click(Sender: TObject); var Bmp: TBitmap; begin Bmp := TBitmap.Create; bmp.Width := RichEdit1.ClientWidth; bmp.Height := RichEdit1.ClientHeight; PrintRTFToBitmap(RichEdit1, Bmp); Image1.Canvas.Draw(0, 0, Bmp); bmp.Free; end; {use PrintToCanvas function} procedure TForm1.Button2Click(Sender: TObject); var Bmp: TBitmap; begin Bmp := TBitmap.Create; bmp.Width := RichEdit1.ClientWidth; bmp.Height := RichEdit1.ClientHeight; PrintToCanvas(bmp.Canvas, 0, Length(RichEdit1.Text), RichEdit1, Bmp.Width, Bmp.Height); Image1.Canvas.Draw(0, 0, Bmp); bmp.Free; end; end.
richviewedit表格设置
table.BorderStyle := rvtbRaisedColor; table.CellBorderStyle := rvtbLoweredColor; table.BorderLightColor := $00FAF1C9; table.BorderColor := $00A98E10; table.CellBorderLightColor := $00FAF1C9; table.CellBorderColor := $00A98E10; table.Color := $00EAC724; table.BorderWidth := 0; table.CellBorderWidth := 2; table.CellPadding := 1; table.CellVSpacing := 1; table.CellHSpacing := 1; table.BorderVSpacing := 1; table.BorderHSpacing := 1;
richviewedit弹出对话框插入链接
FrmUrl.Edit1.Text := Target; if FrmUrl.ShowModal = mrOk then begin Target := FrmUrl.Edit1.Text; if rve.SelectionExists then begin if Target = '' then rve.ApplyStyleConversion(CONVERT_TO_NONHYPERTEXT) else rve.ApplyStyleConversion(CONVERT_TO_HYPERTEXT); SetTargetToSelection(Target); end else if Target = '' then Beep else begin rve.CurTextStyleNo := GetHypertextStyleNo(rve.CurTextStyleNo); rve.InsertStringTag(FrmUrl.Edit2.Text, Target); end; end;
richviewedit压缩保存更新
procedure TMDIChild.FormClose(Sender: TObject; var Action: TCloseAction); var query: TUniQuery; UniConnection:TUniConnection; mstream: TStream; //Stream:TMemoryStream; begin if Self.Tag=1 then begin //需要对文本改变事件进行保存 query:=TUniQuery.Create(nil); UniConnection:=TUniConnection.Create(nil); IF Application.MessageBox('文本已经改变是否保存！','警告',MB_OKCANCEL)=ID_OK then begin try try if RichViewEdit1.Modified then //当已打开的文件被修改了以后 begin mstream:=TMemoryStream.Create; //des:= TStringStream.create(''); //Stream:=TMemoryStream.Create; //RxRichEdit1.Lines.SaveToStream(mstream);//需要对这个流文件进行压缩 //RxRichEdit1.Lines.SaveToStream(Stream);//需要对这个流文件进行压缩 Sqlite_Open(Self.Hint,KeyPwd,UniConnection); query.Connection:=uniConnection; query.SQL.Text :='UPDATE Rich SET F_Con = :F_Con WHERE id = :id' ; query.ParamByName('id').AsString := TitleLbl.Hint; RichViewEdit1.SaveRTFToStream(mstream,false); mStream.Position :=0; query.ParamByName('F_Con').LoadFromStream(mStream, DB.ftBlob); //query.ParamByName('F_Con').LoadFromStream(CompressionStream(Stream), DB.ftBlob); query.Execute; mStream.Free; end; except begin end end; finally query.Free; UniConnection.Free; end; end; end; Action := caFree; end; procedure TMainForm.UpdateRich(Sender: TObject;ID,Title,DBPath:string); var query:TUniQuery; Conn:TUniConnection; Child: TMDIChild; Stream:TStream; begin try Child:=TMDIChild(Sender); Conn:=TUniConnection.Create(nil); Sqlite_Open(DBPath,KeyPwd,Conn); query:=TUniQuery.create(nil); query.Connection := Conn; query.SQL.Clear; query.SQL.Add('Select id,N_name,F_Con from Rich where id=:id'); query.ParamByName('id').AsString := ID;//NodeID; query.Open; if query.RecordCount>0 then if not query.FieldByName('F_Con').IsNull then begin Child.TitleLbl.Caption:=query.FieldByName('N_name').AsString; Child.RichViewEdit1.BeginUpdate; Stream:=TMemoryStream.Create; TBlobField(query.FieldByName('F_Con')).SaveToStream(Stream); Stream.Position := 0; Child.RichViewEdit1.LoadRTFFromStream(Stream); Child.RichViewEdit1.Format; //Stream:=TMemoryStream.Create; //TBlobField(query.FieldByName('F_Con')).SaveToStream(Stream); //Child.rxRichEdit1.Lines.LoadFromStream(UnCompressionStream(Stream)); //Child.rxrichedit1.Lines.EndUpdate; Child.RichViewEdit1.EndUpdate; //Stream.Free; End else begin Child.TitleLbl.Caption:=Title; //Child.rxrichedit1.Clear; Child.RichViewEdit1.Clear; end else begin Child.TitleLbl.Caption:=Title; //Child.rxrichedit1.Clear; Child.RichViewEdit1.Clear; end; query.close; query.Free; Conn.Free; except end; end;
查询表是否存在
cmd.CommandText = "SELECT COUNT(*) FROM sqlite_master where type='table' and name='DBInfo'";
