请问怎么达到这种效果 ?

Question

请查看这个网页,如何画这种跟踪光标的十字线,谢谢!
http://map.zhcw.com/ssq//html/honglan_ascsize=20.html

Answer 1

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, TeeProcs, TeEngine, Chart, Series, StdCtrls;type
  TForm1 = class(TForm)
    Chart1: TChart;
    lineSeries1: TFastLineSeries;
    Label1: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure Chart1MouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure Chart1AfterDraw(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    OldX,OldY:Longint;
    CrossHairColor:TColor;
    CrossHairStyle:TPenStyle;
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.FormCreate(Sender: TObject);
begin
  OldX:=-1;
  CrossHairColor:=clYellow;
  CrossHairStyle:=psSolid;
end;procedure TForm1.Chart1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
  Procedure DrawCross(AX,AY:Integer);
  begin
    With Chart1,Canvas do
    begin
      Pen.Color:=CrossHairColor;
      Pen.Style:=CrossHairStyle;
      Pen.Mode:=pmXor;
      Pen.Width:=1;
      MoveTo(ax,ChartRect.Top-Height3D);
      LineTo(ax,ChartRect.Bottom-Height3D);
      MoveTo(ChartRect.Left+Width3D,ay);
      LineTo(ChartRect.Right+Width3D,ay);
    end;
  end;Var tmpX,tmpY:Double;
begin
  if (OldX<>-1) then
  begin
    DrawCross(OldX,OldY);
    OldX:=-1;
  end;  if PtInRect( Chart1.ChartRect, Point(X-Chart1.Width3D,Y+Chart1.Height3D)  ) then
  begin
    DrawCross(x,y);    OldX:=x;
    OldY:=y;    With LineSeries1 do
    begin
      GetCursorValues(tmpX,tmpY);
      Label1.Caption:=GetVertAxis.LabelValue(tmpY)+
                      ' '+
                      GetHorizAxis.LabelValue(tmpX);
    end;
  end;
end;procedure TForm1.Chart1AfterDraw(Sender: TObject);
begin
  OldX:=-1;
end;end.

Answer 2

function followmouse(){
 leftright.style.top = window.event.y-1
 topdown.style.left = window.event.x-1
}<div  id=\"leftright\" style=\"width:expression(document.getElementById('abox').clientWidth);;height:1px;position:absolute;left:0;top:200px;background-color:#11b700;overflow:hidden;\" \></div>

Answer 3

谢谢楼上两位.我需要在Timage 的图片之上画线,但不能清除底下的image 的图象.请问这个该怎么做呢?

Answer 4

把image 放在一个控件上，在控件上画十字，image放图片

Answer 5

在IMAGE1之上放一个IMAGE2,在IMAGE2上画线,但IMAGE2把IMAGE1的图象遮盖了.  
设置Image2.Transparent := True 也不行,请问是什么原因呢?

Answer 6

bt:=tbitmap.create;
bt.assign(image1.picture.bitmap);
bt.canvas.brush.style:=bsclear;
bt.canvas.moveto(0,0);
bt.canvas.lineto(400,400);
image1.picture.bitmap.assign(bt);
bt.free;下班了 没试验成功 你按这个思路做下看看成不 。

Answer 7

上面有个代码了就那个思路，LZ到TEECHAR的DEMO中找一下也有这个程序源码，用的是鼠标移动定位画线

Answer 8

已经成功了,呵呵
需要加上Image2.Canvas.FillRect(Image2.ClientRect);在画线前先填满背景.谢谢各位!