WPF開發隨筆收錄-WriteableBitmap繪製高性能曲線圖

来源:https://www.cnblogs.com/cong2312/archive/2022/08/05/16553695.html
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一、前言 之前分享過一期關於DrawingVisual來繪製高性能曲線的博客,今天再分享一篇通過另一種方式來繪製高性能曲線的方法,也就是通過WriteableBitmap的方式;具體的一些細節這裡就不啰嗦了,同樣是局部繪製的思想,滾動條拖動到哪裡,就只繪製那一部分的曲線,直接貼代碼;(該程式在英特爾 ...


一、前言

之前分享過一期關於DrawingVisual來繪製高性能曲線的博客,今天再分享一篇通過另一種方式來繪製高性能曲線的方法,也就是通過WriteableBitmap的方式;具體的一些細節這裡就不啰嗦了,同樣是局部繪製的思想,滾動條拖動到哪裡,就只繪製那一部分的曲線,直接貼代碼;(該程式在英特爾11代CPU的電腦可能會遇到拖動滾動條曲線圖卡住不動的情況,這個是顯卡驅動的問題,官方已經修複了,遇到這問題的記得更新一下驅動)

二、正文

1、新建一個類,繼承FrameworkElement,然後在裡面實現一下繪圖的邏輯;

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Text;
using System.IO;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Resources;
using _Font = System.Drawing.Font;
using GDI = System.Drawing;

namespace WriteableBitmapDemo.Controls
{
    public class CruveWriteableBitmap : FrameworkElement
    {
        private static PrivateFontCollection pfc = new PrivateFontCollection();
        private WriteableBitmap bitmap;

        private int bitmap_width = 0;
        private int bitmap_height = 0;

        private static _Font font = null;
        private static _Font time_font = null;

        private PointF[][] horizontals = null;
        private PointF[][] horizontals_thin = null;
        private PointF[][] verticals = null;
        private PointF[][] verticals_thin = null;

        private List<PointF> top_points1;
        private List<PointF> top_points2;
        private List<PointF> top_points3;
        private List<PointF> bottom_points;

        private List<PointF> labelPosition_up;
        private List<string> labelText_up;
        private List<PointF> labelPosition_down;
        private List<string> labelText_down;

        private List<PointF> timePosition;
        private List<string> timeText;

        private GDI.Pen blackPen = new GDI.Pen(GDI.Color.Black, 1.5f);
        private GDI.Pen grayPen = new GDI.Pen(GDI.Color.Gray, 1f);

        private GDI.Pen top_pen1 = new GDI.Pen(GDI.Color.Black, 2);
        private GDI.Pen top_pen2 = new GDI.Pen(GDI.Color.Orange, 2);
        private GDI.Pen top_pen3 = new GDI.Pen(GDI.Color.Purple, 2);public float scaleX { get; set; } = 1f;
        private float _ScaleY { get; set; } = 1f;
        public float ScaleY
        {
            get { return _ScaleY; }
            set
            {
                _ScaleY = value;
            }
        }

        static CruveWriteableBitmap()
        {
            var appRootDataDir = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "msyh.ttf");
            if (!File.Exists(appRootDataDir))
            {
                var key = $"/CurveChartDemo;component/Fonts/msyh.ttf";
                StreamResourceInfo info = Application.GetResourceStream(new Uri(key, UriKind.Relative));
                using (var stream = info.Stream)
                {
                    byte[] bytes = new byte[stream.Length];
                    int len = stream.Read(bytes, 0, bytes.Length);
                    File.WriteAllBytes(appRootDataDir, bytes);
                }
            }
            pfc.AddFontFile(appRootDataDir);
        }

        public CruveWriteableBitmap()
        {
            time_font = new _Font(pfc.Families[0], 10);
            font = new _Font(pfc.Families[0], 8);
        }

        public void DrawPoints()
        {
            //InitBitmap();
            if (this.bitmap == null)
            {
                return;
            }

            this.bitmap.Lock();
            using (Bitmap backBufferBitmap = new Bitmap(this.bitmap_width, this.bitmap_height,
                this.bitmap.BackBufferStride, GDI.Imaging.PixelFormat.Format24bppRgb,
                this.bitmap.BackBuffer))
            {
                using (Graphics backBufferGraphics = Graphics.FromImage(backBufferBitmap))
                {
                    backBufferGraphics.SmoothingMode = SmoothingMode.AntiAlias;
                    backBufferGraphics.CompositingQuality = CompositingQuality.HighSpeed;

                    backBufferGraphics.Clear(GDI.Color.White);

                    //粗橫線
                    if (this.horizontals != null)
                    {
                        foreach (var horizontal in this.horizontals)
                        {
                            backBufferGraphics.DrawLine(blackPen, horizontal[0], horizontal[1]);
                        }
                    }
                    //細橫線
                    if (this.horizontals_thin != null)
                    {
                        foreach (var horizontal in this.horizontals_thin)
                        {
                            backBufferGraphics.DrawLine(grayPen, horizontal[0], horizontal[1]);
                        }
                    }
                    //粗豎線
                    if (this.verticals != null)
                    {
                        foreach (var vertical in this.verticals)
                        {
                            backBufferGraphics.DrawLine(blackPen, vertical[0], vertical[1]);
                        }
                    }
                    //細豎線
                    if (this.verticals_thin != null)
                    {
                        foreach (var vertical in this.verticals_thin)
                        {
                            backBufferGraphics.DrawLine(grayPen, vertical[0], vertical[1]);
                        }
                    }
                    //上圖曲線1
                    if (this.top_points1 != null && this.top_points1.Count > 0)
                    {
                        backBufferGraphics.DrawLines(top_pen1, top_points1.ToArray());
                    }
                    //上圖曲線2
                    if (this.top_points2 != null && this.top_points2.Count > 0)
                    {
                        backBufferGraphics.DrawLines(top_pen2, this.top_points2.ToArray());
                    }
                    //上圖曲線3
                    if (this.top_points3 != null && this.top_points3.Count > 0)
                    {
                        backBufferGraphics.DrawLines(top_pen3, this.top_points3.ToArray());
                    }
                    //下圖曲線
                    if (this.bottom_points != null && this.bottom_points.Count > 0)
                    {
                        backBufferGraphics.DrawLines(top_pen1, this.bottom_points.ToArray());
                    }

                    //文本
                    if (labelPosition_up != null && labelPosition_up.Count > 0)
                    {
                        SizeF fontSize = backBufferGraphics.MeasureString(labelText_up[0], font);
                        for (int i = 0; i < labelPosition_up.Count; ++i)
                        {
                            backBufferGraphics.DrawString(labelText_up[i], font, GDI.Brushes.Black, labelPosition_up[i].X, labelPosition_up[i].Y - fontSize.Height);
                        }
                    }
                    if (labelPosition_down != null && labelPosition_down.Count > 0)
                    {
                        for (int i = 0; i < labelPosition_down.Count; ++i)
                        {
                            backBufferGraphics.DrawString(labelText_down[i], font, GDI.Brushes.Black, labelPosition_down[i].X, labelPosition_down[i].Y);
                        }
                    }
                    if (timePosition != null && timePosition.Count > 0)
                    {
                        for (int i = 0; i < timePosition.Count; ++i)
                        {
                            if (i == 0)
                                backBufferGraphics.DrawString(timeText[i], time_font, GDI.Brushes.Black, timePosition[i].X, timePosition[i].Y);
                            else
                            {
                                SizeF fontSize = backBufferGraphics.MeasureString(timeText[i], time_font);
                                backBufferGraphics.DrawString(timeText[i], time_font, GDI.Brushes.Black, timePosition[i].X - fontSize.Width / 2, timePosition[i].Y);
                            }

                        }
                    }

                    backBufferGraphics.Flush();
                }
            }
            this.bitmap.AddDirtyRect(new Int32Rect(0, 0, this.bitmap_width, this.bitmap_height));
            this.bitmap.Unlock();
        }public void UpdateTimeLabel(List<PointF> timePosition, List<string> timeText)
        {
            this.timePosition = timePosition;
            this.timeText = timeText;
        }
        public void UpdatePosition(List<PointF> fhr1_points, List<PointF> fhr2_points, List<PointF> fhr3_points, List<PointF> toco_points)
        {
            this.top_points1 = fhr1_points;
            this.top_points2 = fhr2_points;
            this.top_points3 = fhr3_points;
            this.bottom_points = toco_points;
        }

        public void UpdateLabelPosition(List<PointF> labelPosition_up, List<string> labelText_up, List<PointF> labelPosition_down, List<string> labelText_down)
        {
            this.labelPosition_up = labelPosition_up;
            this.labelText_up = labelText_up;
            this.labelPosition_down = labelPosition_down;
            this.labelText_down = labelText_down;
        }

        public void UpdateHorizontalLine(PointF[][] horizontals, PointF[][] horizontals_thin)
        {
            this.horizontals = horizontals;
            this.horizontals_thin = horizontals_thin;
        }

        public void UpdateVerticalLine(PointF[][] verticals, PointF[][] verticals_thin)
        {
            this.verticals = verticals;
            this.verticals_thin = verticals_thin;
        }

        protected override void OnRender(DrawingContext dc)
        {
            InitBitmap();
            if (this.bitmap != null)
            {
                dc.DrawImage(bitmap, new Rect(0, 0, RenderSize.Width, RenderSize.Height));
            }
            base.OnRender(dc);
        }

        private void InitBitmap()
        {
            if (bitmap == null || this.bitmap.Width != (int)this.ActualWidth || this.bitmap.Height != (int)this.ActualHeight)
            {
                if ((int)this.ActualWidth > 0 && (int)this.ActualHeight > 0)
                {
                    this.bitmap_width = (int)this.ActualWidth;
                    this.bitmap_height = (int)this.ActualHeight;
                    this.bitmap = new WriteableBitmap(bitmap_width, bitmap_height, 96, 96, PixelFormats.Bgr24, null);
                    this.bitmap.Lock();
                    using (Bitmap backBufferBitmap = new Bitmap(bitmap_width, bitmap_height,
                        this.bitmap.BackBufferStride, GDI.Imaging.PixelFormat.Format24bppRgb,
                        this.bitmap.BackBuffer))
                    {
                        using (Graphics backBufferGraphics = Graphics.FromImage(backBufferBitmap))
                        {
                            backBufferGraphics.SmoothingMode = SmoothingMode.HighSpeed;
                            backBufferGraphics.CompositingQuality = CompositingQuality.HighSpeed;
                            backBufferGraphics.Clear(GDI.Color.White);
                            backBufferGraphics.Flush();
                        }
                    }
                    this.bitmap.AddDirtyRect(new Int32Rect(0, 0, bitmap_width, bitmap_height));
                    this.bitmap.Unlock();
                }
            }
        }
    }
}

2、主視窗添加該控制項,並添加滾動條那些

<Window
    x:Class="WriteableBitmapDemo.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:ct="clr-namespace:WriteableBitmapDemo.Controls"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:WriteableBitmapDemo"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Title="MainWindow"
    Width="1500"
    Height="450"
    Loaded="Window_Loaded"
    mc:Ignorable="d">
    <Grid>
        <ct:CruveWriteableBitmap x:Name="curve" Margin="0,0,0,20" />
        <ScrollViewer
            Name="scroll"
            HorizontalScrollBarVisibility="Auto"
            ScrollChanged="ScrollViewer_ScrollChanged"
            VerticalScrollBarVisibility="Disabled">
            <Canvas x:Name="canvas" Height="1" />
        </ScrollViewer>
        <Canvas
            x:Name="CanvasPanel"
            Margin="0,0,0,20"
            Background="Transparent" />
    </Grid>
</Window>

3、主視窗後臺添加曲線數值生成方法和更新視圖數據方法

using System.Collections.Generic;
using System.Drawing;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace WriteableBitmapDemo
{
    /// <summary>
    /// MainWindow.xaml 的交互邏輯
    /// </summary>
    public partial class MainWindow : Window
    {
        private bool isAdd = true;

        private Dictionary<int, int> dicTopPoints = new Dictionary<int, int>();
        private Dictionary<int, int> dicBottomPoints = new Dictionary<int, int>();

        private float y_scale;

        private static int Top_Val_Max = 240;
        private static int Top_Val_Min = 30;
        private static int Top_X_Sex = 20;
        private static int Bottom = 100;
        private static int Center = 25;
        private static int BottomOffset = 0;

        private double offset = -1;

        public MainWindow()
        {
            InitializeComponent();

            CanvasPanel.MouseMove += delegate (object sender, MouseEventArgs e)
            {
                if (e.LeftButton == MouseButtonState.Pressed)
                {
                    if (Mouse.Captured == null) Mouse.Capture(CanvasPanel);

                    if (offset >= 0 && offset <= CanvasPanel.ActualWidth)
                    {
                        scroll.ScrollToHorizontalOffset(scroll.HorizontalOffset - (e.GetPosition(this).X - offset));
                    }
                    offset = e.GetPosition(this).X;
                }
                else
                {
                    offset = -1;
                    Mouse.Capture(null); // 釋放滑鼠捕獲
                }
            };
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            //生成曲線數據
            int temp = 50;
            for (int i = 0; i < 24 * 60 * 60 * 4; i++)
            {
                if (isAdd)
                {
                    dicTopPoints.Add(i, temp);
                    temp += 2;
                }
                else
                {
                    dicTopPoints.Add(i, temp);
                    temp -= 2;
                }

                if (temp == 210) isAdd = false;
                if (temp == 50) isAdd = true;
            }
            temp = 0;
            for (int i = 0; i < 24 * 60 * 60 * 4; i++)
            {
                if (isAdd)
                {
                    dicBottomPoints.Add(i, temp);
                    temp += 2;
                }
                else
                {
                    dicBottomPoints.Add(i, temp);
                    temp -= 2;
                }

                if (temp == 100) isAdd = false;
                if (temp == 0) isAdd = true;
            }
            //初始化滾動條和觸發曲線繪製
            canvas.Width = dicTopPoints.Count;
            scroll.ScrollToLeftEnd();
        }

        private void ScrollViewer_ScrollChanged(object sender, ScrollChangedEventArgs e)
        {
            InitChartData((float)scroll.HorizontalOffset);
        }

        /// <summary>
        /// 根據滾動條偏移量更新需要繪製的數據
        /// </summary>
        /// <param name="offset"></param>
        private void InitChartData(float offset)
        {
            y_scale = (float)((curve.ActualHeight - Center) / (Top_Val_Max - Top_Val_Min + Bottom));

            //上圖橫線
            List<PointF[]> horizontalList = new List<PointF[]>();
            List<PointF[]> horizontalList_thin = new List<PointF[]>();
            for (int y = 0; y <= Top_Val_Max - Top_Val_Min; y += 10)
            {
                float currentHeight = (float)(curve.ActualHeight - (y + Bottom) * y_scale - Center);
                PointF point1 = new PointF(0, currentHeight);
                PointF point2 = new PointF((float)curve.ActualWidth, currentHeight);
                if (y % 30 == 0)
                    horizontalList.Add(new PointF[] { point1, point2 });
                else
                    horizontalList_thin.Add(new PointF[] { point1, point2 });
            }
            for (int y = 0; y <= Bottom; y += 10)
            {
                float currentHeight = (float)(curve.ActualHeight - y * y_scale - BottomOffset);
                PointF point1 = new PointF(0, currentHeight);
                PointF point2 = new PointF((float)curve.ActualWidth, currentHeight);
                if (y % 20 == 0)
                    horizontalList.Add(new PointF[] { point1, point2 });
                else
                    horizontalList_thin.Add(new PointF[] { point1, point2 });
            }

            //豎線與文字
            List<PointF[]> verticals = new List<PointF[]>();
            List<PointF[]> verticals_thin = new List<PointF[]>();

            List<PointF> timePosition = new List<PointF>();
            List<string> timeText = new List<string>();

            List<PointF> labelPosition_up = new List<PointF>();
            List<string> labelText_up = new List<string>();

            List<PointF> labelPosition_down = new List<PointF>();
            List<string> labelText_down = new List<string>();

            for (int i = 0; i < offset + curve.ActualWidth; i += Top_X_Sex * 2)
            {
                if (i < offset) continue;
                //下豎線
                PointF point1 = new PointF(i - offset, (float)(curve.ActualHeight - BottomOffset));
                PointF point2 = new PointF(i - offset, (float)(curve.ActualHeight - Bottom * y_scale - BottomOffset));
                //上豎線
                PointF point3 = new PointF(i - offset, 0);
                PointF point4 = new PointF(i - offset, (float)(curve.ActualHeight - Bottom * y_scale - Center));

                if ((i + (60 * 2)) % (60 * 2) == 0)
                {
                    verticals.Add(new PointF[] { point1, point2 });
                    verticals.Add(new PointF[] { point3, point4 });
                }
                else
                {
                    verticals_thin.Add(new PointF[] { point1, point2 });
                    verticals_thin.Add(new PointF[] { point3, point4 });
                }

                if (i % 240 == 0)
                {
                    timeText.Add(i + "");
                    timePosition.Add(new PointF(i - offset, (float)(curve.ActualHeight - Bottom * y_scale - Center)));
                }

                if ((i + (60 * 2)) % (120 * 2) == 0)
                {
                    for (int y = Top_Val_Min; y <= Top_Val_Max; y += 10)
                    {
                        if (y % 30 == 0)
                        {
                            labelText_up.Add(y + "");
                            labelPosition_up.Add(new PointF(i - offset, (float)(curve.ActualHeight - (Bottom + y - Top_Val_Min) * y_scale - Center)));
                        }
                    }
                    for (int y = 20; y <= 100; y += 10)
                    {
                        if (y % 20 == 0)
                        {
                            labelText_down.Add(y + "");
                            labelPosition_down.Add(new PointF(i - offset, (float)(curve.ActualHeight - y * y_scale)));
                        }
                    }
                }
            }

            List<PointF> top_points1 = new List<PointF>();
            for (int i = (int)offset, j = 0; i < dicTopPoints.Count && j < curve.ActualWidth; i++, j++)
            {
                top_points1.Add(new PointF(j, (float)(curve.ActualHeight - (dicTopPoints[i] + 100 - Top_Val_Min) * y_scale) - Center));
            }

            List<PointF> top_points2 = new List<PointF>();
            for (int i = (int)offset, j = 0; i < dicTopPoints.Count && j < curve.ActualWidth; i++, j++)
            {
                top_points2.Add(new PointF(j, (float)(curve.ActualHeight - (dicTopPoints[i] + 20 + 100 - Top_Val_Min) * y_scale) - Center));
            }

            List<PointF> top_points3 = new List<PointF>();
            for (int i = (int)offset, j = 0; i < dicTopPoints.Count && j < curve.ActualWidth; i++, j++)
            {
                top_points3.Add(new PointF(j, (float)(curve.ActualHeight - (dicTopPoints[i] - 20 + 100 - Top_Val_Min) * y_scale) - Center));
            }

            List<PointF> bottom_points = new List<PointF>();
            for (int i = (int)offset, j = 0; i < dicBottomPoints.Count && j < curve.ActualWidth; i++, j++)
            {
                bottom_points.Add(new PointF(j, (float)(curve.ActualHeight - dicBottomPoints[i] * y_scale - BottomOffset)));
            }

            curve.UpdateHorizontalLine(horizontalList.ToArray(), horizontalList_thin.ToArray());
            curve.UpdateVerticalLine(verticals.ToArray(), verticals_thin.ToArray());
            curve.UpdatePosition(top_points1, top_points2, top_points3, bottom_points);
            curve.UpdateTimeLabel(timePosition, timeText);
            curve.UpdateLabelPosition(labelPosition_up, labelText_up, labelPosition_down, labelText_down);
            curve.DrawPoints();
        }
    }
}

4、運行效果如下,歡迎各位大佬指點

 


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  • WPF 實現帶蒙版的 MessageBox 消息提示框 WPF 實現帶蒙版的 MessageBox 消息提示框 作者:WPFDevelopersOrg 原文鏈接: https://github.com/WPFDevelopersOrg/WPFDevelopers.Minimal 框架使用大於等於.N ...
  • 一、JSON(JavaScript Object Notation)的簡介: ① JSON和XML類似,主要用於存儲和傳輸文本信息,但是和XML相比,JSON更小、更快、更易解析、更易編寫與閱讀。 ② C、Python、C++、Java、PHP、Go等編程語言都支持JSON。 二、JSON語法規則: ...
  • 1.避免Scoped模式註冊的服務變成Singleton模式 當提供一個生命周期模式為Singleton的服務實例時,如果發現該服務中還依賴生命周期模式為Scoped的服務實例(Scoped服務實例將被一個Singleton服務實例所引用),那麼這個被依賴的Scoped服務實例最終會成為一個Sing ...
  • 索引時資料庫提高數據查詢處理性能的一個非常關鍵的技術,索引的使用可以對性能產生上百倍甚至上千倍的影響。接下來,會介紹索引的基本原理、概念,並深入學習資料庫中所使用的索引結構和存儲方式,以及如何管理、維護索引等。 1.索引的基本概念 索引時用來快速查詢表記錄的一種存儲結構,一般使用索引有一下兩個方面: ...
  • django2 路由控制器 Route路由,是一種映射關係。路由是把客戶端請求的url路徑和用戶請求的應用程式,這裡意指django裡面的視圖進行綁定映射的一種關係。 請求路徑和視圖函數不是一一對應的關係 在django中所有的路由最終都被保存到一個叫urlpatterns的文件里,並且該文件必須在 ...
  • 1、我們的目標是獲取微博某博主的全部圖片、視頻 2、拿到網址後 我們先觀察 打開F12 隨著下滑我們發現載入出來了一個叫mymblog的東西,展開響應發現需要的東西就在裡面 3、重點來了!!! 通過觀察發現第二頁比第一頁多了參數since_id 而第二頁的since_id參數剛好在上一頁中能獲取到, ...
  • 一、實現原理 在Servlet3協議規範中,包含在JAR文件/META-INFO/resources/路徑下的資源可以直接訪問。 二、舉例說明 如下圖所示,是我新建的一個Spring Boot Starter項目:zimug-minitor-threadpool,用於實現可配置、可觀測的線程池。其中 ...
  • 精華筆記: static final常量:應用率高 必須聲明同時初始化 由類名打點來訪問,不能被改變 建議:常量所有字母都大寫,多個單詞用_分隔 編譯器在編譯時會將常量直接替換為具體的數,效率高 何時用:數據永遠不變,並且經常使用 抽象方法: 由abstract修飾 只有方法的定義,沒有具體的實現( ...
  • Python有一個for...else語法,它的寫法如下 for i in range(0,100): if i == 3: break else: print("Not found") 該語句表示:若for迴圈遍歷完畢,則執行else部分的語句。也就是說上述代碼不會有任何輸出,而下述代碼會輸出“N ...