Question

我正在创建一个应用程序，可以在其中移动Labels上的PictureBox。
问题是我只希望这些标签在PictureBox内内移动。

这是我的代码：

protected void lbl_MouseMove(object sender, MouseEventArgs e)
{
    Label lbl = sender as Label;

    try
    {
        if (lbl != null && e.Button == MouseButtons.Left)
        {
            if (m_lblLocation != new Point(0, 0))
            {
                Point newLocation = lbl.Location;
                newLocation.X = newLocation.X + e.X - m_lblLocation.X;
                newLocation.Y = newLocation.Y + e.Y - m_lblLocation.Y;
                lbl.Location = newLocation;
                this.Refresh();
            }
        }
    }
    catch(Exception ex) { }
}

protected void lbl_MouseUp(object sender, MouseEventArgs e)
{
    Label lbl = sender as Label;

    try
    {
        if (lbl != null && e.Button == MouseButtons.Left)
        {
            m_lblLocation = Point.Empty;
        }
    }
    catch(Exception ex) { }
}

protected void lbl_MouseDown(object sender, MouseEventArgs e)
{
    Label lbl = sender as Label;

    try
    {
        if (lbl != null && e.Button == MouseButtons.Left)
        {
            m_lblLocation = e.Location;
        }
    }
    catch(Exception ex) { }
}

在上面的代码中，我为标签创建了一些鼠标事件。

Answer 1

PictureBox控件不是容器，您不能像在Panel，{{1} }或其他实现IContainerControl的控件。
您可以为GroupBox设置父级（在这种情况下），将Label父级设置为Label句柄。 PictureBox随后将反映父级Label.Bounds。
但是，这不是必需的：您只需计算相对于同时包含（Bounds（s）和Label）的控件的Label位置：

您可以限制订阅PictureBox事件的其他Label控件的移动。

一个例子：

MovableLabel_MouseDown/MouseUp/MouseMove

Answer 2

您需要跟踪两件事： 1.是否按下鼠标-bool IsMouseDown = false; 2.标签的起始位置-Point StartPoint;

// mouse is not down
private void label1_MouseUp(object sender, MouseEventArgs e)
{
    IsMouseDown = false;
}


 //mouse is down and set the starting postion
 private void label1_MouseDown(object sender, MouseEventArgs e)
 {   
     //if left mouse button was pressed
     if (e.Button == System.Windows.Forms.MouseButtons.Left)
     {
         IsMouseDown = true;
         label1.BringToFront();
         StartPoint = e.Location;
      }
   }


    //check the label is withing the borders of the picture box
    private void label1_MouseMove(object sender, MouseEventArgs e)
    {
        if (IsMouseDown)
        {
            int left = e.X + label1.Left - StartPoint.X;
            int right = e.X + label1.Right - StartPoint.X;
            int top = e.Y + label1.Top - StartPoint.Y;
            int bottom = e.Y + label1.Bottom - StartPoint.Y;
            if (left > pictureBox1.Left && top > pictureBox1.Top && pictureBox1.Bottom >= bottom && pictureBox1.Right >= right)
            {
                label1.Left = left;
                label1.Top = top;
            }
        }
    }

不要将标签移到PictureBox外部

2 个答案: