WPF数据可视化-瀑布图

实现方式一：

将数据（Point[]）根据索引沿X轴使用虚拟画布进行绘制，每个数据绘制大小为1px * 1px；最终绘制出的宽度等于数据的总长度。标记并存储当前绘制的图为PreviousBitmap; 继续置顶绘制第二组数据，第二组数据绘制完后，将标记的PreviousBitmap作为Image在Y轴距离顶部距离为1px的地方用DrawingContext.DrawImage()方式绘制，以此类推。核心代码如下：

private void DoAddDataArray(Point[] arrPoints)

{

    this.Dispatcher.Invoke(DispatcherPriority.Normal, new Action(() =>

    {

        double dPixelWidth = Pixel;

        double dContainerWidth = this.VbxContainer.ActualWidth;

        double dContainerHeight = this.VbxContainer.ActualHeight;

        double dPixelHeight = Pixel/2d;

        double dCellHeight = 1;

        double dCellWidth = 1;

        DrawingVisual drawingVisual = new DrawingVisual();

        DrawingContext drawingContext = drawingVisual.RenderOpen();

        drawingContext.DrawRectangle(new SolidColorBrush(Colors.Blue),

                new Pen(), new Rect(0, 0, dPixelWidth, dCellHeight));

        // 绘制新数据

        for (int i = 0; i < arrPoints.Length; i++)

        {

            double dCellX = Math.Round(((arrPoints[i].X - MinAxisX) / (MaxAxisX - MinAxisX)) * Pixel);

            double dY = arrPoints[i].Y;

            Color oColor = this.GetColor(dY);

            //drawingContext.DrawRectangle(new SolidColorBrush(oColor),

            //    new Pen(), new Rect(dCellX, 0, dCellWidth, dCellHeight));

            LinearGradientBrush lineBrush = new LinearGradientBrush();

            lineBrush.GradientStops.Add(new GradientStop(Colors.Transparent, 0));

            lineBrush.GradientStops.Add(new GradientStop(oColor, 0.25));

            lineBrush.GradientStops.Add(new GradientStop(oColor, 0.5));

            lineBrush.GradientStops.Add(new GradientStop(oColor, 0.75));

            lineBrush.GradientStops.Add(new GradientStop(Colors.Transparent, 1));

            drawingContext.DrawRectangle(lineBrush, new Pen(), new Rect(dCellX-1, 0, dCellWidth + 2, dCellHeight));

        }    

        // 绘制历史数据

        if (this.PreviousBitmap != null)

            drawingContext.DrawImage(this.PreviousBitmap, new Rect(0, dCellHeight, dPixelWidth, dPixelHeight));

        drawingContext.Close();

        // 生成图像处理

        RenderTargetBitmap rtbCurrent = new RenderTargetBitmap((int)dPixelWidth,

            (int)dPixelHeight, 96, 96, PixelFormats.Pbgra32);

        rtbCurrent.Render(drawingVisual);

        this.PreviousBitmap = rtbCurrent; // 当前绘制的存为历史，下次绘制时直接调用

        this.ImgMain.Source = rtbCurrent; // 显示绘制的图像

    }));

}

运行效果

实现方式二：

将数据（Point[]）根据索引沿X轴使用虚拟画布进行绘制，每个数据绘制大小为1px * 1px；最终绘制出的宽度等于数据的总长度。创建一个Rectangle，将绘制的图赋值给Rectangle.Fill属性，将绘制过程中不断创建的Rectangle插入控件Stackpanel的首位。核心代码如下：

private void DoAddDataArray(Point[] arrPoints)

{

    this.Dispatcher.Invoke(DispatcherPriority.Normal, new Action(() =>

    {

        double dPixelWidth = Pixel;

        double dContainerWidth = this.VbxContainer.ActualWidth;

        double dContainerHeight = this.VbxContainer.ActualHeight;

        double dPixelHeight = Pixel / 2d;

        DrawingVisual drawingVisual = new DrawingVisual();

        DrawingContext drawingContext = drawingVisual.RenderOpen();

        drawingContext.DrawRectangle(new SolidColorBrush(Colors.Blue),

                new Pen(), new Rect(, , dPixelWidth, ));

        // 绘制新数据

        double dCellHeight = ;

        double dCellWidth = ;

        for (int i = ; i < arrPoints.Length; i++)

        {

            double dCellX = Math.Round(((arrPoints[i].X - MinAxisX) / (MaxAxisX - MinAxisX)) * Pixel);

            double dY = arrPoints[i].Y;

            Color oColor = this.GetColor(dY);

            //drawingContext.DrawRectangle(new SolidColorBrush(oColor),

            //    new Pen(), new Rect(dCellX, 0, dCellWidth, dCellHeight));

            LinearGradientBrush lineBrush = new LinearGradientBrush();

            lineBrush.GradientStops.Add(new GradientStop(Colors.Transparent, ));

            lineBrush.GradientStops.Add(new GradientStop(oColor, 0.25));

            lineBrush.GradientStops.Add(new GradientStop(oColor, 0.5));

            lineBrush.GradientStops.Add(new GradientStop(oColor, 0.75));

            lineBrush.GradientStops.Add(new GradientStop(Colors.Transparent, ));

            drawingContext.DrawRectangle(lineBrush, new Pen(), new Rect(dCellX - 0.5, , dCellWidth + , dCellHeight));

        }

        drawingContext.Close();

        // 生成图像处理

        RenderTargetBitmap rtbCurrent = new RenderTargetBitmap((int)dPixelWidth, (int), , , PixelFormats.Pbgra32);

        rtbCurrent.Render(drawingVisual);

        Rectangle rect = new Rectangle();

        rect.Width = Pixel;

        rect.Height = ;

        rect.Fill = new ImageBrush(rtbCurrent);

        // SpContainers  ---- Stackpanel

        this.SpContainers.Children.Insert(, rect);

        if (this.SpContainers.Children.Count > )

            this.SpContainers.Children.RemoveAt();

    }));

}