• WPF Adorner 简易图片取色器


    回答MSDN问题所写。

    使用Adorner+附加属性

    图片类(来自这位博主的博客

      /// <summary>
        /// 用于获取位图像素的类
        /// </summary>
        public class Imghelper
        {
            /// <summary>
            /// 位图宽度
            /// </summary>
            public int Width { get; protected set; }
            /// <summary>
            /// 位图高度
            /// </summary>
            public int Height { get; protected set; }
            /// <summary>
            /// 像素
            /// </summary>
            public Color[][] Pixels { get; protected set; }
    
            /// <summary>
            /// 根据指定的位图生成BitmapPixelHelper类的新实例。
            /// </summary>
            /// <param name="bitmap">指定的位图</param>
            public Imghelper(BitmapSource bitmap)
            {
                FormatConvertedBitmap newBitmap = new FormatConvertedBitmap(bitmap, PixelFormats.Bgra32, BitmapPalettes.WebPaletteTransparent, 0);
                const int bytesPerPixel = 4;
                Height = newBitmap.PixelHeight;
                Width = newBitmap.PixelWidth;
                byte[] data = new byte[Height * Width * bytesPerPixel];
                newBitmap.CopyPixels(data, Width * bytesPerPixel, 0);
    
                Pixels = new Color[Height][];
                for (int i = 0; i < Height; ++i)
                {
                    Pixels[i] = new Color[Width];
                    for (int j = 0; j < Width; ++j)
                    {
                        Pixels[i][j] = Color.FromArgb(
                            data[(i * Width + j) * bytesPerPixel + 3],
                            data[(i * Width + j) * bytesPerPixel + 2],
                            data[(i * Width + j) * bytesPerPixel + 1],
                            data[(i * Width + j) * bytesPerPixel + 0]);
                    }
                }
            }
    
            /// <summary>
            /// 获取图片的平均色
            /// </summary>
            public Color GetAverageColor()
            {
                int a = 0, r = 0, g = 0, b = 0;
                for (int i = 0; i < Height; ++i)
                {
                    for (int j = 0; j < Width; ++j)
                    {
                        a += Pixels[i][j].A;
                        r += Pixels[i][j].R;
                        g += Pixels[i][j].G;
                        b += Pixels[i][j].B;
                    }
                }
                a = a / Height / Width;
                r = r / Height / Width;
                g = g / Height / Width;
                b = b / Height / Width;
                return Color.FromArgb((byte)a, (byte)r, (byte)g, (byte)b);
            }
        }

    adorner代码

    public class ShowImagePixelsPopup : Adorner
        {
    
            private TextBlock GetTextBlock;
            private VisualCollection collection;
            private UIElement _UIElement;
            private Border GetBorder;
    
    
            public ShowImagePixelsPopup(UIElement adornedElement) : base(adornedElement)
            {
                collection = new VisualCollection(this);
    
                GetTextBlock = new TextBlock();
    
                GetTextBlock.Height = 20;
                GetTextBlock.Width = 120;
                GetTextBlock.Background = new SolidColorBrush(Colors.Wheat); 
                GetTextBlock.HorizontalAlignment = HorizontalAlignment.Left;
                GetTextBlock.VerticalAlignment = VerticalAlignment.Top;
                GetBorder = new Border();
                GetBorder.Height = 15;
                GetBorder.Width = 15;
                GetBorder.HorizontalAlignment = HorizontalAlignment.Left;
                GetBorder.VerticalAlignment = VerticalAlignment.Top;
                collection.Add(GetTextBlock);
                collection.Add(GetBorder);
                _UIElement = adornedElement;
            }
            protected override int VisualChildrenCount => collection.Count;
    
    
            protected override Visual GetVisualChild(int index) => collection[index];
    
    
            protected override Size MeasureOverride(Size constraint) => base.MeasureOverride(constraint);
    
            public void SetData(Point MousePoint, String Pixels,Color color)
            {
                GetTextBlock.Margin = new Thickness(MousePoint.X+7.5, MousePoint.Y-15, 0,0);
                GetBorder.Margin = new Thickness(MousePoint.X-7.5 , MousePoint.Y-7.5 , 0, 0);
                GetBorder.Background = new SolidColorBrush(color);
                GetTextBlock.Text = Pixels;
            }
    
            protected override Size ArrangeOverride(Size finalSize)
            {
                GetTextBlock.Arrange(new Rect(finalSize));
                GetBorder.Arrange(new Rect(finalSize));
                return base.ArrangeOverride(finalSize);
    
            }
        }
    

    附加属性类

    public class IsShowImagePixels
        {
            public static readonly DependencyProperty IsShowImagePixelsProperty = DependencyProperty.RegisterAttached("IsShowImagePixels", typeof(bool), typeof(IsShowImagePixels), new PropertyMetadata(false, new PropertyChangedCallback(OnIsShowImagePixelsChanged)));
    
            public static void SetIsShowImagePixels(DependencyObject d, bool value) => d.SetValue(IsShowImagePixelsProperty, value);
    
            public static bool GetIsShowImagePixels(DependencyObject d) => (bool)d.GetValue(IsShowImagePixelsProperty);
    
            public static readonly DependencyProperty ShowImagePixelsPointProperty = DependencyProperty.RegisterAttached("ShowImagePixelsPoint", typeof(Point), typeof(IsShowImagePixels), new PropertyMetadata(new Point(0, 0),new PropertyChangedCallback(OnShowImagePixelsPointChanged)));
    
            public static void SetIsShowImagePixelsPoint(DependencyObject d, Point value) => d.SetValue(ShowImagePixelsPointProperty, value);
    
            public static Point GetShowImagePixelsPoint(DependencyObject d) => (Point)d.GetValue(ShowImagePixelsPointProperty);
    
            private static void OnShowImagePixelsPointChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
            {
                var c =(Point)e.NewValue;
    
                popup.SetData(c, $"X={(((int)c.X ) < 0 ? 0 : (int)c.X )},Y={(((int)c.Y ) < 0 ? 0 : (int)c.Y )}", imghelper.Pixels[((int)c.Y - 1) < 0 ? 0 : (int)c.Y - 1][((int)c.X - 1) < 0 ? 0 : (int)c.X - 1]);
    
            }
            private static AdornerLayer layer;
            private static Imghelper imghelper;
            private static ShowImagePixelsPopup popup;
    
            private static void OnIsShowImagePixelsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
            {
    
                var NewValue = (bool)e.NewValue;
                UIElement element = d as UIElement;
                if (!NewValue)
                {
    
                    AdornerLayer l = AdornerLayer.GetAdornerLayer(element);
                    var ado = l.GetAdorners(element);
                    for (var o = 0; o < ado.Length; o++)
                        l.Remove(ado[o]);
                    element.MouseMove -= Element_MouseMove;
                   
                    imghelper = null;
                    popup = null;
                    layer = null;
                    element = null;
                }
                if (element == null)
                    return;
                layer = AdornerLayer.GetAdornerLayer(element);
                popup = new ShowImagePixelsPopup(element);
                layer.Add(popup);
                imghelper = new Imghelper((element as Image).Source as BitmapSource);
                //显示鼠标位置
                element.MouseMove += Element_MouseMove;       
            }
    
            
    
            private static void Element_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
            {
    
                var c = e.GetPosition(sender as FrameworkElement);
                //此处只是用了鼠标位置,也可以用ShowImagePixelsPoint直接指定位置
                popup.SetData(c, $"X={(((int)c.X - 1) < 0 ? 0 : (int)c.X - 1)},Y={(((int)c.Y - 1) < 0 ? 0 : (int)c.Y - 1)}", imghelper.Pixels[((int)c.Y - 1) < 0 ? 0 : (int)c.Y - 1][((int)c.X - 1) < 0 ? 0 : (int)c.X - 1]);
    
            }
        }

    xaml代码

    <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="*"/>
                <RowDefinition Height="auto"/>
            </Grid.RowDefinitions>
            <AdornerDecorator Grid.Row="0">
                <Image x:Name="img"  />
            </AdornerDecorator>
            <Button Click="Button_Click" Grid.Row="1" Height="40" Content="ShowOrNot"/>
        </Grid>

    cs页面代码

      public partial class MainWindow : Window
        {
            public MainWindow()
            {
                InitializeComponent();
                var b = new BitmapImage(new Uri("timg.jpg", UriKind.RelativeOrAbsolute));
                Imghelper imghelper = new Imghelper(b);
                img.Source = b;
                img.SetValue(IsShowImagePixels.IsShowImagePixelsProperty, true);
                Set = true;
            }
            private bool Set = false;
            private void Button_Click(object sender, RoutedEventArgs e)
            {
               
                if (Set)
                    Set = false;
                else
                    Set = true;
                img.SetValue(IsShowImagePixels.IsShowImagePixelsProperty, Set);
                return;
    
            }
        }
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  • 原文地址:https://www.cnblogs.com/T-ARF/p/11504048.html
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