倒置垂直进度条

支持视觉样式的代码包含一些bug。这段代码:

 ProgressBarRenderer.DrawVerticalBar(e.Graphics, e.ClipRectangle);

必须用下面的替换:

ProgressBarRenderer.DrawVerticalBar(e.Graphics, ClientRectangle);

和我重新发布完整的源代码没有这个错误:

public class VerticalProgressBar : ProgressBar
    {
        protected override CreateParams CreateParams
        {
            get
            {
                // Avoid CA2122
                new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Demand();
                CreateParams cp = base.CreateParams;
                cp.Style |= 0x04;
                return cp;
            }
        }
        public VerticalProgressBar()
        {
            // Enable OnPaint overriding
            this.SetStyle(ControlStyles.UserPaint, true);
        }
        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            if (ProgressBarRenderer.IsSupported)
            {
                ProgressBarRenderer.DrawVerticalBar(e.Graphics, ClientRectangle);
                const int HORIZ_OFFSET = 3;
                const int VERT_OFFSET = 2;
                if (this.Minimum == this.Maximum || (this.Value - Minimum) == 0 ||
                        this.Height < 2 * VERT_OFFSET || this.Width < 2 * VERT_OFFSET)
                    return;
                int barHeight = (this.Value - this.Minimum) * this.Height / (this.Maximum - this.Minimum);
                barHeight = Math.Min(barHeight, this.Height - 2 * VERT_OFFSET);
                int barWidth = this.Width - 2 * HORIZ_OFFSET;
                if (this.RightToLeftLayout && this.RightToLeft == System.Windows.Forms.RightToLeft.No)
                {
                    ProgressBarRenderer.DrawVerticalChunks(e.Graphics,
                            new Rectangle(HORIZ_OFFSET, VERT_OFFSET, barWidth, barHeight));
                }
                else
                {
                    int blockHeight = 10;
                    int wholeBarHeight = Convert.ToInt32(barHeight / blockHeight) * blockHeight;
                    int wholeBarY = this.Height - wholeBarHeight - VERT_OFFSET;
                    int restBarHeight = barHeight % blockHeight;
                    int restBarY = this.Height - barHeight - VERT_OFFSET;
                    ProgressBarRenderer.DrawVerticalChunks(e.Graphics,
                        new Rectangle(HORIZ_OFFSET, wholeBarY, barWidth, wholeBarHeight));
                    ProgressBarRenderer.DrawVerticalChunks(e.Graphics,
                        new Rectangle(HORIZ_OFFSET, restBarY, barWidth, restBarHeight));
                }
            }
            base.OnPaint(e);
        }
    }

似乎没有任何CreateParams支持倒垂直ProgressBar。这些是来自Windows API的样式参数:

#define PBS_SMOOTH          0x01
#define PBS_VERTICAL        0x04
#define PBS_MARQUEE         0x08
#define PBS_SMOOTHREVERSE   0x10
#define PBST_NORMAL         1
#define PBST_ERROR          2
#define PBST_PAUSED         3

我尝试改变rightolleft的值，但无济于事。似乎也没有办法任意旋转Windows窗体控件。

一个可能的解决方案可能是使用WPF的进度条。你可以把它旋转90度，它应该是你想要的。另一个选择是使用第三方Progressbar控件或创建一个自定义呈现控件。呈现一个简单的平面进度条应该是相当容易的。

你必须像这样重写OnPaint():

public class VerticalProgressBar : ProgressBar
{
    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams cp = base.CreateParams;
            cp.Style |= 0x04;
            return cp;
        }
    }
    public VerticalProgressBar()
    {
        // Enable OnPaint overriding
        this.SetStyle(ControlStyles.UserPaint, true);
    }
    protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
    {
        Graphics dc = e.Graphics;
        if (this.Minimum == this.Maximum || (this.Value - Minimum) == 0)
            return;
        int width = this.Width;                                                                 // The bar width
        int height = (this.Value - this.Minimum) * this.Height / (this.Maximum - this.Minimum); // The bar height
        int x = 2;                          // The bottom-left x pos of the bar (or upper left on upsidedown bar)
        int y = this.Height - 1;            // The bottom-left y pos of the bar (or upper left on upsidedown bar)
        int blockheight = width * 3 / 4;    // The height of the block
        if (this.RightToLeftLayout && this.RightToLeft == System.Windows.Forms.RightToLeft.No)
            for (int currentpos = 0; currentpos < height; currentpos += blockheight + 1)
                dc.FillRectangle(new SolidBrush(this.ForeColor), x, currentpos, width, blockheight);
        else
            for (int currentpos = y; currentpos > y - height; currentpos -= blockheight + 1)
                dc.FillRectangle(new SolidBrush(this.ForeColor), x, currentpos - blockheight, width, blockheight);
        base.OnPaint(e);
    }
}

现在你可以用同样的方式使用它你链接的垂直进度条和LeftToRight/righttolleft功能将模仿正常的进度条(关于进度绘制方向)。

我注意到上面的代码不能很好地处理视觉样式。下面是垂直进度条的改进版本，它应该覆盖视觉样式:

public class VerticalProgressBar : ProgressBar
{
    protected override CreateParams CreateParams
    {
        get
        {
            // Avoid CA2122
            new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Demand();  
            CreateParams cp = base.CreateParams;
            cp.Style |= 0x04;
            return cp;
        }
    }
    public VerticalProgressBar()
    {
        // Enable OnPaint overriding
        this.SetStyle(ControlStyles.UserPaint, true);
    }
    protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
    {
        if (ProgressBarRenderer.IsSupported)
        {
            ProgressBarRenderer.DrawVerticalBar(e.Graphics, e.ClipRectangle);
            const int HORIZ_OFFSET = 3;
            const int VERT_OFFSET = 2;
            if (this.Minimum == this.Maximum || (this.Value - Minimum) == 0 ||
                    this.Height < 2 * VERT_OFFSET || this.Width < 2 * VERT_OFFSET)
                return;
            int barHeight = (this.Value - this.Minimum) * this.Height / (this.Maximum - this.Minimum);
            barHeight = Math.Min(barHeight, this.Height - 2 * VERT_OFFSET);
            int barWidth = this.Width - 2 * HORIZ_OFFSET;
            if (this.RightToLeftLayout && this.RightToLeft == System.Windows.Forms.RightToLeft.No)
            {
                ProgressBarRenderer.DrawVerticalChunks(e.Graphics,
                        new Rectangle(HORIZ_OFFSET, VERT_OFFSET, barWidth, barHeight));
            }
            else
            {
                int blockHeight = 10;
                int wholeBarHeight = Convert.ToInt32(barHeight / blockHeight) * blockHeight;
                int wholeBarY = this.Height - wholeBarHeight - VERT_OFFSET;
                int restBarHeight = barHeight % blockHeight;
                int restBarY = this.Height - barHeight - VERT_OFFSET;
                ProgressBarRenderer.DrawVerticalChunks(e.Graphics,
                    new Rectangle(HORIZ_OFFSET, wholeBarY, barWidth, wholeBarHeight));
                ProgressBarRenderer.DrawVerticalChunks(e.Graphics,
                    new Rectangle(HORIZ_OFFSET, restBarY, barWidth, restBarHeight));
            }
        }
        base.OnPaint(e);
    }
}

我必须为自下而上的进度条绘制单独的块，因为我想保持其他进度条的外观和感觉。否则，该条会看起来是从中间绘制的。