在PictureBox1父控件内调整自定义控件大小时越界问题求助

我正在开发一款特殊绘图应用，允许用户在单个窗体上编辑多个PictureBox的尺寸。目前尝试在名为picturebox1的父控件内调整自定义控件大小，但无论向哪个方向调整，控件都会超出父控件边界。

以下是三个鼠标事件的代码：

MouseMove事件 #

private void MoveControl(Object sender, MouseEventArgs e)
{
    Control control = (Control)sender;

    if (!_resizing && !_moving)
    {
        UpdateMouseEdgeProperties(control, new Point(e.X, e.Y));
        UpdateMouseCursor(control);
    }

    if (_resizing)
    {
        pictureBox1.Invalidate();
        if (MouseIsInLeftEdge)
        {
            if (MouseIsInTopEdge)
            {
                control.Width -= (e.X - _cursorStartPoint.X);
                control.Left += (e.X - _cursorStartPoint.X);
                control.Height -= (e.Y - _cursorStartPoint.Y);
            }
            else if (MouseIsInBottomEdge)
            {
                control.Width -= (e.X - _cursorStartPoint.X);
                control.Left += (e.X - _cursorStartPoint.X);
                control.Height = (e.Y - _cursorStartPoint.Y) + _currentControlStartSize.Height;
            }
            else
            {
                control.Width -= (e.X - _cursorStartPoint.X);
                control.Left += (e.X - _cursorStartPoint.X);
            }
        }
        else if (MouseIsInRightEdge)
        {
            if (MouseIsInTopEdge)
            {
                control.Width = (e.X - _cursorStartPoint.X) + _currentControlStartSize.Width;
                control.Height -= (e.Y - _cursorStartPoint.Y);
                control.Top += (e.Y - _cursorStartPoint.Y);
            }
            else if (MouseIsInBottomEdge)
            {
                control.Width = (e.X - _cursorStartPoint.X) + _currentControlStartSize.Width;
                control.Height = (e.Y - _cursorStartPoint.Y) + _currentControlStartSize.Height;
            }
            else
            {
                control.Width -= (e.X - _cursorStartPoint.X);
                control.Left += (e.X - _cursorStartPoint.X);
            }
        }
        else if (MouseIsInTopEdge)
        {
            control.Height -= (e.Y - _cursorStartPoint.Y);
            control.Top += (e.Y - _cursorStartPoint.Y);
        }
        else if (MouseIsInBottomEdge)
        {
            control.Height = (e.Y - _cursorStartPoint.Y) + _currentControlStartSize.Height;
        }
        else
        {
            StopDragOrResizing(control);
        }
    }
    else if (_moving)
    {
        _moveIsInterNal = !_moveIsInterNal;
        if (!_moveIsInterNal)
        {
            int nx = Math.Min(Math.Max(control.Left + (e.X - start.X), 0), pictureBox1.Width - control.Width);
            int ny = Math.Min(Math.Max(control.Top + (e.Y - start.Y), 0), pictureBox1.Height - control.Height);

            control.Location = new Point(nx, ny);
        }
    }
}

MouseDown事件 #

private void StartMovingOrResizing(Object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        xPos = e.X;
        yPos = e.Y;
        start = e.Location;
    }

    Control control = (Control)sender;

    if (_moving || _resizing)
    {
        return;
    }
    if (WorkType != MoveOrResize.Move &&
        (MouseIsInRightEdge || MouseIsInLeftEdge || MouseIsInTopEdge || MouseIsInBottomEdge))
    {
        _resizing = true;
        _currentControlStartSize = control.Size;
    }
    else if (WorkType != MoveOrResize.Resize)
    {
        _moving = true;
        control.Cursor = Cursors.Hand;
    }
    _cursorStartPoint = new Point(e.X, e.Y);
    control.Capture = true;

    DrawControlBorder(control);
    control.Invalidate();
    pictureBox1.Invalidate();
}

MouseUp事件 #

private void StopDragOrResizing(Object sender, MouseEventArgs e)
{
    Control control = (Control)sender;

    _resizing = false;
    _moving = false;
    control.Capture = false;
    UpdateMouseCursor(control);

    control.Invalidate();
    DrawControlBorder(control);
}

补充说明：

• 代码来自第三方教程
• 试过多个在线项目均不符合需求，且WndProc命令会与项目其他部分冲突

内容的提问来源于stack exchange，提问作者Bullish Programmer 117