Image1->Canvas->Rectangle(...)会闪屏？怎么去掉闪屏？请给最简单的示例代码，谢谢！急急急！ ( 积分: 17 )

void __fastcall TForm1::Image1MouseMove(TObject *Sender, TShiftState Shift,
int X, int Y)
{
if(m_bMouseDown)
{
switch(m_nDrawType)
{
case 0:
{
Image1->Canvas->Pen->Mode = pmNotXor;
Image1->Canvas->Rectangle(m_ptMouseDown.x, m_ptMouseDown.y,
m_ptMouseMove.x, m_ptMouseMove.y);
Image1->Canvas->Rectangle(m_ptMouseDown.x, m_ptMouseDown.y, X, Y);

}
break;

case 1:
{
}
break;
}
}
m_ptMouseMove.x = X;
m_ptMouseMove.y = Y;
}

void __fastcall TForm1::Image1MouseMove(TObject *Sender, TShiftState Shift,
int X, int Y)
{
if(m_bMouseDown)
{
switch(m_nDrawType)
{
case 0:
{
Image1->Canvas->Pen->Mode = pmNotXor;
Image1->Canvas->Rectangle(m_ptMouseDown.x, m_ptMouseDown.y,
m_ptMouseMove.x, m_ptMouseMove.y);
Image1->Canvas->Rectangle(m_ptMouseDown.x, m_ptMouseDown.y, X, Y);

}
break;

case 1:
{
}
break;
}
}
m_ptMouseMove.x = X;
m_ptMouseMove.y = Y;
}

Form1.DoubleBuffer:=True;
就可以了,也就是双缓存模式.

Form1.DoubleBuffer:=True;
不过，您这么写，如果画笔是黑的，并且画笔比较粗的时候，当两个矩形相交的地方是白色的。

闪屏的原因是由于刷新前后图像反差大造成的视觉效果，你先在内存建立一个和TImage同样大小的TBitmap，在其上把图像全部画完，之后直接绘制到Image.Canvas上就不会闪烁了。

之后把这个TBitmap直接绘制到Image.Canvas上就不会闪烁了。TImage.Canvas.Draw(0,0,TheBitmap);