如何通过鼠标在Panel中移动pictureBox

How to move a pictureBox inside a Panel by Mouse. Visual Studio 2015 C# Winsows Forms Application.

如何通过鼠标在Panel中移动pictureBox。 Visual Studio 2015 C＃Winsows Forms应用程序。

I've made a primitive slider to control the volume of my WindowsMediaPlayer. A panel as the background and a pictureBox inside as the slider-knopf. And it works well. But purely visually it does not work that good.

我制作了一个原始的滑块来控制我的WindowsMediaPlayer的音量。一个面板作为背景，一个pictureBox作为slider-knopf。它运作良好。但纯粹在视觉上它并没有那么好用。

I'v searched all around, but can't I find an answer to this little funny problem.

我四处寻找，但我无法找到这个有趣的小问题的答案。

Here is my code:

这是我的代码：

    int posY;

    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            posY = e.Y; ;
        }
    }

    private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
        PictureBox box = sender as PictureBox;

        if (e.Button == MouseButtons.Left)
        {
            box.Top += e.Y - posY;
        }

        if (box.Top < 0)
        {
            box.Top = 0;
        }

        if (box.Top > 100)
        {
            box.Top = 100;
        }
        int n = box.Top;
        n = n * - 1 + 100;
        label1.Text = n.ToString();
    }

When I move the pictureBox out of the edge of the little panel, the pictureBox somehow 'shrinks' in the panel. But when I release the mouse, the pictureBox restore its size.

当我将pictureBox从小面板的边缘移开时，pictureBox在面板中以某种方式“收缩”。但是当我释放鼠标时，pictureBox恢复了它的大小。

Slider.gif

Slider.gif

Why is that.? And how can I avoid it.?

这是为什么。？我怎么能避免它。

Thanks.

谢谢。

1 个解决方案

#1

I found a solution. It's not optimal, but it can be used. I changed the code to:

我找到了解决方案。它不是最佳的，但它可以使用。我将代码更改为：

    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            dragging = true;
            startPoint = e.Location;
        }
    }


    private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
        if (dragging)
        {
            Debug.WriteLine("mousemove X: " + e.X + " Y: " + e.Y);
            pictureBox1.Location = new Point(0, pictureBox1.Top + e.Location.Y - startPoint.Y);

            if (pictureBox1.Location.Y < 0)
            {
                pictureBox1.Location = new Point(0, 0);
                dragging = false;
            }
            if (pictureBox1.Location.Y > 100)
            {
                pictureBox1.Location = new Point(0, 100);
                dragging = false;
            }
            this.Refresh();
        }
        int n = pictureBox1.Location.Y;
        n = n * -1 + 100;
        label1.Text = n.ToString();

        mediaPlayer1.settings.volume = n;
    }


    private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
    {
        dragging = false;
    }

gif

GIF

I still need to put an 'if' to correct, when the pictureBox1 is pulled out of the panel. And to avoid flicker, I have had to put a 'dragging = false'. However, it results in the pictureBox1 is getting frozen to the edge, so I have to release the mouse, and re-click to continue.

当pictureBox1被拉出面板时，我仍然需要设置'if'来纠正。为了避免闪烁，我不得不设置'拖动=假'。但是，它导致pictureBox1被冻结到边缘，所以我必须释放鼠标，然后重新单击继续。

But well - it's to live with.

但是好吧 - 这就是生活。

Thanks.

谢谢。