滚动问题！

Question

我已经在我的表单中实现了一个图片框。我甚至实现了滚动条以使图像适合它。现在问题是当我尝试向下滚动按钮时，它向下滚动并立即当我离开时鼠标按钮向上滚动..代码实现请给出一些建议..

     public void DisplayScrollBars()
    {
        // If the image is wider than the PictureBox, show the HScrollBar.
        if (pictureBox1.Width > pictureBox1.Image.Width - this.vScrollBar1.Width)
        {
            hScrollBar1.Visible = false;
        }
        else
        {
            hScrollBar1.Visible = true;
        }

        // If the image is taller than the PictureBox, show the VScrollBar.
        if (pictureBox1.Height >
            pictureBox1.Image.Height - this.hScrollBar1.Height)
        {
            vScrollBar1.Visible = false;
        }
        else
        {
            vScrollBar1.Visible = true;
        }
    }

    private void HandleScroll(Object sender, ScrollEventArgs se)
    {
        /* Create a graphics object and draw a portion 
           of the image in the PictureBox. */
        Graphics g = pictureBox1.CreateGraphics();

        g.DrawImage(pictureBox1.Image,
          new Rectangle(0, 0, pictureBox1.Right - vScrollBar1.Width,
          pictureBox1.Bottom - hScrollBar1.Height),
          new Rectangle(hScrollBar1.Value, vScrollBar1.Value,
          pictureBox1.Right - vScrollBar1.Width,
          pictureBox1.Bottom - hScrollBar1.Height),
          GraphicsUnit.Pixel);


        pictureBox1.Update();
    }


    public void SetScrollBarValues()
    {
        // Set the Maximum, Minimum, LargeChange and SmallChange properties.
        this.vScrollBar1.Minimum = 0;
        this.hScrollBar1.Minimum = 0;


        // If the offset does not make the Maximum less than zero, set its value. 
        if ((this.pictureBox1.Image.Size.Width - pictureBox1.ClientSize.Width) > 0)
        {
            this.hScrollBar1.Maximum =
                this.pictureBox1.Image.Size.Width - pictureBox1.ClientSize.Width;
        }
        // If the VScrollBar is visible, adjust the Maximum of the 
        // HSCrollBar to account for the width of the VScrollBar.  
        if (this.vScrollBar1.Visible)
        {
            this.hScrollBar1.Maximum += this.vScrollBar1.Width;
        }
        this.hScrollBar1.LargeChange = this.hScrollBar1.Maximum / 10;
        this.hScrollBar1.SmallChange = this.hScrollBar1.Maximum / 20;


        // Adjust the Maximum value to make the raw Maximum value 
        // attainable by user interaction.
        this.hScrollBar1.Maximum += this.hScrollBar1.LargeChange;

        // If the offset does not make the Maximum less than zero, set its value.    
        if ((this.pictureBox1.Image.Size.Height - pictureBox1.ClientSize.Height) > 0)
        {
            this.vScrollBar1.Maximum =
                this.pictureBox1.Image.Size.Height - pictureBox1.ClientSize.Height;
        }


        // If the HScrollBar is visible, adjust the Maximum of the 
        // VSCrollBar to account for the width of the HScrollBar.
        if (this.hScrollBar1.Visible)
        {
            this.vScrollBar1.Maximum += this.hScrollBar1.Height;
        }
        this.vScrollBar1.LargeChange = this.vScrollBar1.Maximum / 10;
        this.vScrollBar1.SmallChange = this.vScrollBar1.Maximum / 20;

        // Adjust the Maximum value to make the raw Maximum value 
        // attainable by user interaction.
        this.vScrollBar1.Maximum += this.vScrollBar1.LargeChange;
    }

    private void pictureBox1_Resize(object sender, EventArgs e)
    {
        // If the PictureBox has an image, see if it needs 
        // scrollbars and refresh the image. 
        if (pictureBox1.Image != null)
        {
            this.DisplayScrollBars();
            this.SetScrollBarValues();
            this.Refresh();
        }
    }

Answer 1

正如我在上面评论的那样，正确的方法是将pictureBox放在panel并设置panel.AutoScroll=true。您还需要设置pictureBox.SizeMode=AutoSize，使其大小等于其包含的图像大小。检查：PictureBoxSizeMode Enumeration