Image不能动态改变width,heigth的情况？？改了也无法在增大后的区域绘图！！(100分)

Image不能动态改变width,heigth的情况？？改了也无法在增大后的区域绘图！！
我发现 liuchuanbo 的 方法不行，再次发贴请大家讨论这个问题。

philips：你试过我的回答吗.

To :
Fudei

我试过你的方法，不过我是用鼠标通过拖动方法来确定Image的大小，以pixel绘图，

第一次正确，第二次如果绘图区小，还可以，大了则不行。

既然第一次可以，那么你可以试着每次确定大小后，绘图前动态创建Image元件，

这样问题不就解决了吗。

listen

philips: 我不是说得吗. 你要想图象完全覆盖image（图象大小<image）
就使用image的属性stretch=True; autosize=false;

啊! 被吃了部分，再来：
philips: 我不是说得吗. 你要想图象完全覆盖image（图象大小小于image）
就使用image的属性stretch=True; autosize=false;

过会儿，我把代码贴出来，大家帮我侃侃。

//---------------------------------------------------------------------
#include <vcl.h>
#include <math.h>
#pragma hdrstop
#include "Child0form.h"
//---------------------------------------------------------------------
#pragma resource "*.dfm"

TPoint StartPt,EndPt;
bool bDrawing = False, bDraging = False;

//---------------------------------------------------------------------
__fastcall TfrmChild0::TfrmChild0(TComponent *Owner)
: TForm(Owner)
{
}
//---------------------------------------------------------------------

void __fastcall TfrmChild0::Image1MouseUp(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
int itop,ileft;

if( bDrawing )
{
bDrawing = False;
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);
//Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);

Image1->Canvas->Pen->Mode = pmCopy;
Image1->Canvas->Pen->Color = clBlack;
Image1->Canvas->Brush->Style = bsClear;

itop = Image1->Top;
ileft = Image1->Left;
Image2->Height = abs(EndPt.y - StartPt.y);
Image2->Width = abs(EndPt.x - StartPt.x);
Image2->Left = (StartPt.x>EndPt.x ? EndPt.x :StartPt.x) +ileft;
Image2->Top = (StartPt.y>EndPt.y ? EndPt.y :StartPt.y) +itop;

for(int i=0;i<Image2->Height;i++)
for(int j=0;j<Image2->Width;j++)
{
if( Image2->Canvas->Pixels[j]==clRed )
Image2->Canvas->Pixels[j]=clGreen;
else
Image2->Canvas->Pixels[j]=clRed;
}

Image2->Visible = True;
}
}
//---------------------------------------------------------------------------

void __fastcall TfrmChild0::Image1MouseDown(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
Image2->Visible = False;
Image1->Canvas->Pen->Color = clWhite;
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);

bDrawing = True;
StartPt = TPoint(X,Y);
EndPt = StartPt;

Image1->Canvas->Pen->Mode = pmNot;
Image1->Canvas->Pen->Color = clRed;
Image1->Canvas->Brush->Style =bsClear;
Image1->Canvas->Pen->Style = psDot;
}
//---------------------------------------------------------------------------

void __fastcall TfrmChild0::Image1MouseMove(TObject *Sender,
TShiftState Shift, int X, int Y)
{
if( bDrawing &amp;&amp; ((EndPt.x != X)||(EndPt.y != Y)) )
{
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, X,Y);
EndPt.x = X;
EndPt.y = Y;
}
}
//---------------------------------------------------------------------------

void __fastcall TfrmChild0::Image2MouseDown(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
StartPt.x = X;
StartPt.y = Y;
bDraging = True;
}
//---------------------------------------------------------------------------

void __fastcall TfrmChild0::Image2MouseMove(TObject *Sender,
TShiftState Shift, int X, int Y)
{ if( bDraging )
{
Image2->Left = Image2->Left +X - StartPt.x;
Image2->Top = Image2->Top + Y - StartPt.y;
Image2->Hint = "X:"+IntToStr(Image2->Left)+" Y:"+IntToStr(Image2->Top);
}

}
//---------------------------------------------------------------------------

void __fastcall TfrmChild0::Image2MouseUp(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
bDraging = False;
}
//---------------------------------------------------------------------------

void __fastcall TfrmChild0::FormCreate(TObject *Sender)
{
int i,y;

for (i=1;i<Image1->Height; i++)
{
y=100*sin(i/180.0*3.1415);
Image1->Canvas->Pixels[y+200] = clRed;
}

}
//---------------------------------------------------------------------------

以上为我的代码，我欲选种部分曲线，用拖动的方法移动它。请大家帮忙改改。

上面程序 漏掉了 这两行：
#include <vcl.h>
#include <math.h>

上面的程序在复制时出了问题， 应该是这样的：

#include <vcl.h>
#include <math.h>
#pragma hdrstop
#include "Child0form.h"

#pragma resource "*.dfm"

TPoint StartPt,EndPt;
bool bDrawing = False, bDraging = False;


__fastcall TfrmChild0::TfrmChild0(TComponent *Owner)
: TForm(Owner)
{
}


void __fastcall TfrmChild0::Image1MouseUp(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
int itop,ileft;

if( bDrawing )
{
bDrawing = False;
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);
//Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);

Image1->Canvas->Pen->Mode = pmCopy;
Image1->Canvas->Pen->Color = clBlack;
Image1->Canvas->Brush->Style = bsClear;

itop = Image1->Top;
ileft = Image1->Left;
Image2->Height = abs(EndPt.y - StartPt.y);//在这修改Image的大小
Image2->Width = abs(EndPt.x - StartPt.x);//在这修改Image的大小
Image2->Left = (StartPt.x>EndPt.x ? EndPt.x :StartPt.x) +ileft;
Image2->Top = (StartPt.y>EndPt.y ? EndPt.y :StartPt.y) +itop;

for(int i=0;i<Image2->Height;i++)
for(int j=0;j<Image2->Width;j++)
{
if( Image2->Canvas->Pixels[j]==clRed )
Image2->Canvas->Pixels[j]=clGreen;
else
Image2->Canvas->Pixels[j]=clRed;
}

Image2->Visible = True;
}
}


void __fastcall TfrmChild0::Image1MouseDown(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
Image2->Visible = False;
Image1->Canvas->Pen->Color = clWhite;
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);

bDrawing = True;
StartPt = TPoint(X,Y);
EndPt = StartPt;

Image1->Canvas->Pen->Mode = pmNot;
Image1->Canvas->Pen->Color = clRed;
Image1->Canvas->Brush->Style =bsClear;
Image1->Canvas->Pen->Style = psDot;
}


void __fastcall TfrmChild0::Image1MouseMove(TObject *Sender,
TShiftState Shift, int X, int Y)
{
if( bDrawing &amp;&amp; ((EndPt.x != X)||(EndPt.y != Y)) )
{
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, EndPt.x,EndPt.y);
Image1->Canvas->Rectangle(StartPt.x,StartPt.y, X,Y);
EndPt.x = X;
EndPt.y = Y;
}
}


void __fastcall TfrmChild0::Image2MouseDown(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
StartPt.x = X;
StartPt.y = Y;
bDraging = True;
}


void __fastcall TfrmChild0::Image2MouseMove(TObject *Sender,
TShiftState Shift, int X, int Y)
{ if( bDraging )
{
Image2->Left = Image2->Left +X - StartPt.x;
Image2->Top = Image2->Top + Y - StartPt.y;
Image2->Hint = "X:"+IntToStr(Image2->Left)+" Y:"+IntToStr(Image2->Top);
}
}


void __fastcall TfrmChild0::Image2MouseUp(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
bDraging = False;
}


void __fastcall TfrmChild0::FormCreate(TObject *Sender)
{
int i,y;

for (i=1;i<Image1->Height; i++)
{
y=100*sin(i/180.0*3.1415);
Image1->Canvas->Pixels[y+200] = clRed;
}

}

上面程序 漏掉了 这两行：
#include "vcl.h"
#include "math.h"

怎么总是 漏掉小（大）于号？
上面的程序的思路正确吗？ 有无更好的方法解决？

我快急疯了！Wu....

看看以前的解答

请各位大侠帮帮我，拜托了！

c++? I don't know.
好象觉得你是在image上画线, 当拖动它时就不能在多出的区域画了是吗？
是否你的变量被固定了大小,当你结束image拖动时，就无法按你光标位置
画线了,也可试下image的OnProgress事件.

???

今天有有 5 分，可以全加上。

我的程序 是先在image1上画线, 当鼠标在Image1上拖动时，动态绘制巨型橡皮线，

松开鼠标后，确定了Image2的位置和大小，我将 Image2 所覆盖的Image1区域的曲

线复制到 Image2上， 然而，不能按照 Image2 的大小画线。

问题就是这样， 请大侠关注以下。拜托！！！