WPF自定義控件開發實例 - ColorPicker

時間 2019-12-08

標籤 wpf 自定義控件開發實例 colorpicker 简体版

原文原文鏈接

開發環境:Win10 + VS2017 + .Net4.5編程

這個 ColorPicker 是<<WPF編程寶典:使用C#2012和.NET4.5>>這本書中的例子.這裏我記錄一下,主要是爲了加深印象,防止之後要開發自定義控件的時候忘記一些基本的步驟,能夠隨時來查一下.
調到博文的最後能夠先查看一下效果圖.markdown

創建ColorPicker類繼承自 Control類

爲何繼承自 Control,Control類繼承自UIElement -> FrameworkElement -> ColorPicker,同時 Control 類提供了 Template 功能.ide

通知WPF,將爲控件提供新的樣式.
方法是在靜態構造函數中調用 OverrideMetadata()方法.函數

static ColorPicker()
 {
     DefaultStyleKeyProperty.OverrideMetadata(
         typeof(ColorPicker), new FrameworkPropertyMetadata(typeof(ColorPicker)));
 }

編寫控件邏輯,添加一些必要的屬性|事件|方法 ...this
重寫 OnApplyTemplate 方法,爲模板中的元素添加數據綁定或者關聯事件處理程序spa

ColorPicker類的完整代碼:code

using System;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
 using System.Windows.Data;
 using System.Windows.Media;

 namespace Demo.DIYControl.Controls.DeepInDIY
 {
     [TemplatePart(Name = RedSliderName,Type = typeof(RangeBase))]
     [TemplatePart(Name = GreenSliderName, Type = typeof(RangeBase))]
     [TemplatePart(Name = BlueSliderName, Type = typeof(RangeBase))]
     [TemplatePart(Name = PreviewBrushName, Type = typeof(SolidColorBrush))]
     public class ColorPicker:Control
     {
         private const string RedSliderName = "PART_RedSlider";
         private const string GreenSliderName = "PART_GreenSlider";
         private const string BlueSliderName = "PART_BlueSlider";
         private const string PreviewBrushName = "PART_PreviewBrush";

         private Brush _initializeBorderBrush;
         

         public const byte RGBMaxValue = 255;

         public byte Red
         {
             get { return (byte)GetValue(RedProperty); }
             set { SetValue(RedProperty, value); }
         }
         // Using a DependencyProperty as the backing store for Red.  This enables animation, styling, binding, etc...
         public static readonly DependencyProperty RedProperty =
             DependencyProperty.Register(
                 nameof(Red), typeof(byte), typeof(ColorPicker), 
                 new FrameworkPropertyMetadata(OnColorRGBChanged));

         public byte Green
         {
             get { return (byte)GetValue(GreenProperty); }
             set { SetValue(GreenProperty, value); }
         }
         // Using a DependencyProperty as the backing store for Green.  This enables animation, styling, binding, etc...
         public static readonly DependencyProperty GreenProperty =
             DependencyProperty.Register(
                 nameof(Green), typeof(byte), typeof(ColorPicker), 
                 new FrameworkPropertyMetadata(OnColorRGBChanged));

         public byte Blue
         {
             get { return (byte)GetValue(BlueProperty); }
             set { SetValue(BlueProperty, value); }
         }
         // Using a DependencyProperty as the backing store for Blue.  This enables animation, styling, binding, etc...
         public static readonly DependencyProperty BlueProperty =
             DependencyProperty.Register(
                 nameof(Blue), typeof(byte), typeof(ColorPicker), 
                 new FrameworkPropertyMetadata(OnColorRGBChanged));

         public Color Color
         {
             get { return (Color)GetValue(ColorProperty); }
             set { SetValue(ColorProperty, value); }
         }
         // Using a DependencyProperty as the backing store for Color.  This enables animation, styling, binding, etc...
         public static readonly DependencyProperty ColorProperty =
             DependencyProperty.Register(nameof(Color), typeof(Color), 
                 typeof(ColorPicker), new FrameworkPropertyMetadata(Colors.Black,OnColorChanged));

         public CornerRadius CornerRadius
         {
             get { return (CornerRadius)GetValue(CornerRadiusProperty); }
             set { SetValue(CornerRadiusProperty, value); }
         }
         // Using a DependencyProperty as the backing store for CornerRadius.  This enables animation, styling, binding, etc...
         public static readonly DependencyProperty CornerRadiusProperty =
             DependencyProperty.Register("CornerRadius", typeof(CornerRadius), typeof(ColorPicker), 
                 new FrameworkPropertyMetadata(default(CornerRadius)));

         public bool UseDynamicBorder
         {
             get { return (bool)GetValue(UseDynamicBorderProperty); }
             set { SetValue(UseDynamicBorderProperty, value); }
         }
         // Using a DependencyProperty as the backing store for UseDynamicBorder.  This enables animation, styling, binding, etc...
         public static readonly DependencyProperty UseDynamicBorderProperty =
             DependencyProperty.Register(
                 "UseDynamicBorder", typeof(bool), typeof(ColorPicker), 
                 new FrameworkPropertyMetadata(true, OnUseDynamicBorderChanged));


         public static readonly RoutedEvent ColorChangedEvent = EventManager.RegisterRoutedEvent(
             "ColorChangedEvent", RoutingStrategy.Bubble,
             typeof(RoutedPropertyChangedEventHandler<Color>), typeof(ColorPicker));
         public event RoutedPropertyChangedEventHandler<Color> ColorChanged
         {
             add { AddHandler(ColorChangedEvent, value); }
             remove { RemoveHandler(ColorChangedEvent, value); }
         }

         static ColorPicker()
         {
             DefaultStyleKeyProperty.OverrideMetadata(
                 typeof(ColorPicker), new FrameworkPropertyMetadata(typeof(ColorPicker)));
         }

         public ColorPicker()
         {
             Loaded += (sender, args) =>
             {
                 _initializeBorderBrush = BorderBrush;   //save initial borderbrush
                 BorderBrush = UseDynamicBorder? new SolidColorBrush(Color) : BorderBrush;
             };
         }


         private static void OnColorRGBChanged(DependencyObject sender,
             DependencyPropertyChangedEventArgs args)
         {
             ColorPicker colorPicker = sender as ColorPicker;
             colorPicker = colorPicker ?? throw new ArgumentException();

             Color color = colorPicker.Color;
             if (args.Property == RedProperty)
                 color.R = (byte)args.NewValue;
             else if (args.Property == GreenProperty)
                 color.G = (byte)args.NewValue;
             else if (args.Property == BlueProperty)
                 color.B = (byte)args.NewValue;

             colorPicker.Color = color;
         }

         private static void OnColorChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {
             ColorPicker colorPicker = d as ColorPicker;
             d = d ?? throw new ArgumentException();
             colorPicker.Red = colorPicker.Color.R;
             colorPicker.Green = colorPicker.Color.G;
             colorPicker.Blue = colorPicker.Color.B;

             //set border color
             if (colorPicker.UseDynamicBorder)
                 colorPicker.BorderBrush = new SolidColorBrush(colorPicker.Color);

             colorPicker.RaiseEvent(
                 new RoutedEventArgs(ColorChangedEvent, e.NewValue));
         }

         private static void OnUseDynamicBorderChanged(
             DependencyObject d, DependencyPropertyChangedEventArgs args)
         {
             ColorPicker colorPicker = d as ColorPicker;
             colorPicker = colorPicker ?? throw new ArgumentException();

             colorPicker.BorderBrush = (bool)args.NewValue ? new SolidColorBrush(colorPicker.Color) : colorPicker._initializeBorderBrush;
         }

         public override void OnApplyTemplate()
         {
             base.OnApplyTemplate();

             RangeBase slider = GetTemplateChild("PART_RedSlider") as RangeBase;
             if (slider != null)
             {
                 Binding binding = new Binding()
                 {
                     Path = new PropertyPath("Red"),
                     Source = this,
                     Mode = BindingMode.TwoWay
                 };
                 slider.SetBinding(RangeBase.ValueProperty, binding);
                 slider.Maximum = RGBMaxValue;
             }

             slider = GetTemplateChild("PART_GreenSlider") as RangeBase;
             if (slider != null)
             {
                 Binding binding = new Binding()
                 {
                     Path = new PropertyPath(nameof(Green)),
                     Source = this,
                     Mode = BindingMode.TwoWay
                 };
                 slider.SetBinding(RangeBase.ValueProperty, binding);
                 slider.Maximum = RGBMaxValue;
             }

             slider = GetTemplateChild("PART_BlueSlider") as RangeBase;
             if (slider != null)
             {
                 Binding binding = new Binding()
                 {
                     Path = new PropertyPath(nameof(Blue)),
                     Source = this,
                     Mode = BindingMode.TwoWay
                 };
                 slider.SetBinding(RangeBase.ValueProperty, binding);
                 slider.Maximum = RGBMaxValue;
             }

             SolidColorBrush brush = GetTemplateChild("PART_PreviewBrush") as SolidColorBrush;
             if (brush != null)
             {
                 Binding bd = new Binding
                 {
                     Path = new PropertyPath(nameof(brush.Color)),
                     Source = brush,
                     Mode = BindingMode.OneWayToSource
                 };
                 SetBinding(ColorPicker.ColorProperty, bd);
             }
         }

     }
 }