如何画一条直线,编辑时可移动它,可定位它、查看它的属性

Question

紧急求助。

Answer 1

给你一个例子：
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls, ImgList, ComCtrls;type
  TDrawingTool = (dtLine, dtRectangle, dtEllipse, dtRoundRect);
  TNode = Record
    rectx1 : integer;
    rectx2 : integer;
    recty1 : integer;
    recty2 : integer;
    name : string;
    pic : tpicture;
    //rect : trect;
  end;  TLine =record
    StartPt,EndPt :TPoint;
  end;  TForm1 = class(TForm)
    ScrollBox1: TScrollBox;
    Image1: TImage;
    TreeView1: TTreeView;
    ImageList1: TImageList;
    procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormCreate(Sender: TObject);
    procedure Image1MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure TreeView1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
  private
    { Private declarations }
    pic : tpicture;
    name : string;
    drawing,moving,Lining : Boolean;
    picnode : array of TNode;
    ArrLine :array of TLine;
    nodecount,nodeselectNo : integer;
    LineCount,LineSelectNo :integer;
    origin, movept :TPoint;
    DrawingTool: TDrawingTool;
    procedure DrawShape(TopLeft, BottomRight: TPoint; AMode: TPenMode);
    procedure RefreshImage;
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.DFM}procedure TForm1.RefreshImage;
var i :integer;
beginend;procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  i : integer;
  tmprect : trect;
begin
  if button = mbleft then
  begin
    if drawing then
    begin
      image1.Canvas.Draw(x,y,pic.Graphic);
      setlength(picNode,nodeCount+1);
      picnode[nodecount].rectx1 := x;
      picnode[nodecount].recty1 := y;
      picnode[nodecount].rectx2 := x + pic.Width;
      picnode[nodecount].recty2 := y + pic.Height;
      picnode[nodecount].name := name;
      picnode[nodecount].pic := tpicture.Create;
      picnode[nodecount].pic := pic;
      image1.Canvas.TextOut(picnode[nodecount].rectx1,picnode[nodecount].recty2,picnode[nodecount].name);
      nodecount := nodecount + 1;
      drawing := False;
    end
    else
    begin
      for i := 0 to nodecount do
      begin
        tmprect := rect(picnode[i].rectx1,picnode[i].recty1,picnode[i].rectx2,picnode[i].recty2);
        if ptinrect(tmprect,point(x,y)) then
        begin
          moving := true;
          nodeselectNo := i;
          break;
        end;
      end;
    end;
  end else if Button =mbRight then
  begin
    for i := 0 to nodecount do
    begin
      tmprect := rect(picnode[i].rectx1,picnode[i].recty1,picnode[i].rectx2,picnode[i].recty2);
      if ptinrect(tmprect,point(x,y)) then
      begin
        //moving := true;
        nodeselectNo := i;
        DrawingTool :=dtLine;
        lining :=true;
        Origin :=point(x,y);
        MovePt := Origin;
        break;
      end;
    end;
  end;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
  nodecount := 0;
  LineCount :=0;
  setlength(picnode,30);
  drawing := false;
  moving := false;
  Lining :=false;
end;procedure TForm1.Image1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  tmprect : trect;
  i :integer;
  CanLine :Boolean;
begin
  CanLine :=False;
  if button = mbleft then
  begin
    if moving then
    begin
      tmprect := rect(picnode[nodeselectno].rectx1,picnode[nodeselectno].recty1,picnode[nodeselectno].rectx2,picnode[nodeselectno].recty2);
      image1.Canvas.FillRect(tmpRect);
      image1.Canvas.Brush.Color := clWhite;
      image1.Canvas.TextOut(picnode[nodeselectno].rectx1,picnode[nodeselectno].recty2,'                  ');
      image1.Canvas.Draw(x,y,picnode[nodeselectno].pic.Graphic);
      picnode[nodeselectno].rectx1 := x;
      picnode[nodeselectno].recty1 := y;
      picnode[nodeselectno].rectx2 := x + picnode[nodeselectno].pic.Width;
      picnode[nodeselectno].recty2 := y + picnode[nodeselectno].pic.Height;
      image1.Canvas.TextOut(picnode[nodeselectno].rectx1,picnode[nodeselectno].recty2,picnode[nodeselectno].name);
      for i :=0 to Length(ArrLine)-1 do
      begin
        if ptInRect(tmpRect,ArrLine[i].StartPt) then
        begin
          DrawShape(Point(x,y),ArrLine[i].EndPt,PmCopy);
          DrawShape(ArrLine[i].StartPt,ArrLine[i].EndPt,pmNotXor);
          ArrLine[i].StartPt :=Point(x,y);
        end else if  ptInRect(tmpRect,ArrLine[i].EndPt) then
        begin
          DrawShape(ArrLine[i].StartPt,Point(x,y),PmCopy);
          DrawShape(ArrLine[i].StartPt,ArrLine[i].EndPt,pmNotXor);
          ArrLine[i].EndPt :=Point(x,y);
        end;
      end;
      image1.Refresh;      
      moving := false;
    end;
  end else if button =mbRight then
  begin
    if lining then
    begin
      for i := 0 to nodecount do
      begin
        tmprect := rect(picnode[i].rectx1,picnode[i].recty1,picnode[i].rectx2,picnode[i].recty2);
        if ptinrect(tmprect,point(x,y)) then
        begin
          CanLine :=True;
          break;
        end;
      end;
      if CanLine then
      begin
        DrawShape(Origin, Point(X, Y), pmCopy);
        inc(LineCount);
        setlength(ArrLine,LineCount);
        ArrLine[LineCount-1].StartPt :=Origin;
        ArrLine[LineCount-1].EndPt :=Point(x,y);
        lining :=false;
      end else
      begin
        DrawShape(Origin,Point(x,y),pmNotXor);
        lining :=false;
      end;
    end;
  end;
end;procedure TForm1.TreeView1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  i : integer;
  bmp : tbitmap;
begin
  for i := 0 to Treeview1.Items.Count - 1 do
  begin
    if Treeview1.Items[i].Selected then
    begin
      pic := TPicture.Create;
      bmp :=TBitmap.Create;
      ImageList1.GetBitmap(Treeview1.Items[i].ImageIndex,bmp);
      //SelectIndex := i;
      pic.Assign(bmp);
      Drawing :=True;
      name :=TreeView1.Items[i].Text;
      bmp.Free;
    end;
  end;
end;procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
var
  i : integer;
begin
  pic.Free;
  for i := 0 to nodecount-1 do
    picnode[nodecount].pic.Free;
end;procedure TForm1.Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if lining then
  begin
    DrawShape(Origin, MovePt, pmNotXor);
    MovePt := Point(X, Y);
    DrawShape(Origin, MovePt, pmNotXor);
  end;
end;procedure TForm1.DrawShape(TopLeft, BottomRight: TPoint; AMode: TPenMode);
begin
  with Image1.Canvas do
  begin
    Pen.Mode := AMode;
    case DrawingTool of
      dtLine:
        begin
          Image1.Canvas.MoveTo(TopLeft.X, TopLeft.Y);
          Image1.Canvas.LineTo(BottomRight.X, BottomRight.Y);
        end;
      dtRectangle: Image1.Canvas.Rectangle(TopLeft.X, TopLeft.Y, BottomRight.X,
        BottomRight.Y);
      dtEllipse: Image1.Canvas.Ellipse(Topleft.X, TopLeft.Y, BottomRight.X,
        BottomRight.Y);
      dtRoundRect: Image1.Canvas.RoundRect(TopLeft.X, TopLeft.Y, BottomRight.X,
        BottomRight.Y, (TopLeft.X - BottomRight.X) div 2,
        (TopLeft.Y - BottomRight.Y) div 2);
    end;
  end;
end;end.

Answer 2

或许你干脆就用个TShape，把高度或宽度缩小一些，再设一下填充颜色，让它看起来象条线就行。

Answer 3

http://www.csdn.net/cnshare/soft/13/13995.shtm

Answer 4

movingboy(movingboy)提供的方法非常方便
TShape的Height为1
这时候TShape就是一条直线

Answer 5

TPanel高度为2，不就条线吗。

Answer 6

留下油箱或给我发邮件,我有一个例子.
[email protected]

Answer 7

假如用panel当作线，呵呵，斜线怎么办？