绑定元素属性改变不通知界面

情景假设：绑定的是一个Point，当Point的X或者Y属性发生改变时，绑定的点也随界面改变

此时界面不会发生改变

原因：当X或者Y属性发生改变时并没有触发Point的Set方法

 1   <Grid>
 2         <Grid.Resources>
 3             <local:PConverter x:Key="converter"/>
 4             <local:PointsConverter x:Key="pointsC"/>
 5
 6             <Style TargetType="Ellipse">
 7                 <Setter Property="Height" Value="5"/>
 8                 <Setter Property="Width" Value="5"/>
 9                 <Setter Property="HorizontalAlignment" Value="Left"/>
10                 <Setter Property="VerticalAlignment" Value="Top"/>
11             </Style>
12         </Grid.Resources>
13
14
15         <Grid.ColumnDefinitions>
16             <ColumnDefinition/>
17             <ColumnDefinition/>
18         </Grid.ColumnDefinitions>
19
20
21         <Grid x:Name="PathGrid" Grid.Column="0">
22             <Border BorderBrush="AliceBlue" BorderThickness="5"/>
23
24             <Path Stroke="BlueViolet" StrokeThickness="3">
25                 <Path.Data>
26                     <PathGeometry>
27                         <PathFigure StartPoint="{Binding ElementName=OwnerWindow,Path=StartPoint}">
28                             <PathFigure.Segments>
29                                 <PolyBezierSegment
30                                     IsSmoothJoin="True"
31                                     Points="{Binding ElementName=OwnerWindow,Path=Points,Converter={StaticResource pointsC},UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
32                             </PathFigure.Segments>
33                         </PathFigure>
34                     </PathGeometry>
35                 </Path.Data>
36             </Path>
37         </Grid>
38
39         <StackPanel Grid.Column="1">
40             <StackPanel>
41                 <Label>请输入StartPoint坐标</Label>
42                 <StackPanel Orientation="Horizontal">
43                     <Label>X:</Label>
44                     <TextBox Width="50" Text="{Binding ElementName=OwnerWindow,Path=XStartPoint,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
45                     <Label>Y:</Label>
46                     <TextBox Width="50" Text="{Binding ElementName=OwnerWindow,Path=YStartPoint,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
47                 </StackPanel>
48             </StackPanel>
49             <StackPanel>
50                 <Label>请输入EndPoint坐标</Label>
51                 <StackPanel Orientation="Horizontal">
52                     <Label>X:</Label>
53                     <TextBox Width="50" Text="{Binding ElementName=OwnerWindow,Path=XEndPoint,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
54                     <Label>Y:</Label>
55                     <TextBox Width="50" Text="{Binding ElementName=OwnerWindow,Path=YEndPoint,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
56                 </StackPanel>
57             </StackPanel>
58             <StackPanel>
59                 <Label>请输入路线经过的坐标点</Label>
60                 <StackPanel Orientation="Horizontal">
61                     <Label>X:</Label>
62                     <TextBox Width="50" Text="{Binding ElementName=OwnerWindow,Path=XPoint,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
63                     <Label>Y:</Label>
64                     <TextBox Width="50" Text="{Binding ElementName=OwnerWindow,Path=YPoint,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"/>
65                     <Button Height="20" Click="Button_Click">增加</Button>
66                 </StackPanel>
67             </StackPanel>
68
69             <ListBox  Height="100"
70                 ItemsSource="{Binding ElementName=OwnerWindow,Path=Points}"/>
71         </StackPanel>
72     </Grid>

  1 private ObservableCollection<Point> points = new ObservableCollection<Point>();
  2
  3         public ObservableCollection<Point> Points
  4         {
  5             get { return points; }
  6             set{points = value;}
  7         }
  8
  9
 10
 11
 12
 13
 14         public Point StartPoint
 15         {
 16             get { return (Point)GetValue(StartPointProperty); }
 17             set { SetValue(StartPointProperty, value); }
 18         }
 19
 20         // Using a DependencyProperty as the backing store for StartPoint.  This enables animation, styling, binding, etc...
 21         public static readonly DependencyProperty StartPointProperty =
 22             DependencyProperty.Register("StartPoint", typeof(Point), typeof(PathAnimationDemo), new PropertyMetadata(new Point(0, 0)));
 23
 24
 25
 26         public Point EndPoint
 27         {
 28             get { return (Point)GetValue(EndPointProperty); }
 29             set
 30             {
 31                 SetValue(EndPointProperty, value);
 32                 this.OnPropertyChanged("EndPoint");
 33             }
 34         }
 35
 36         // Using a DependencyProperty as the backing store for EndPoint.  This enables animation, styling, binding, etc...
 37         public static readonly DependencyProperty EndPointProperty =
 38             DependencyProperty.Register("EndPoint", typeof(Point), typeof(PathAnimationDemo), new PropertyMetadata(new Point(100, 100)));
 39
 40         private double xStartPoint;
 41
 42         public double XStartPoint
 43         {
 44             get { return this.StartPoint.X; }
 45             set
 46             {
 47                 xStartPoint = value;
 48                 this.StartPoint = new Point(xStartPoint, this.StartPoint.X);
 49             }
 50         }
 51
 52
 53         private double yStartPoint;
 54
 55         public double YStartPoint
 56         {
 57             get { return this.StartPoint.Y; }
 58             set
 59             {
 60                 yStartPoint = value;
 61                 this.StartPoint = new Point(this.StartPoint.X, yStartPoint);
 62             }
 63         }
 64
 65         private double xEndPoint;
 66
 67         public double XEndPoint
 68         {
 69             get { return this.EndPoint.X; }
 70             set
 71             {
 72                 xEndPoint = value;
 73                 this.EndPoint = new Point(xEndPoint, this.EndPoint.Y);
 74             }
 75         }
 76
 77         private double yEndPoint;
 78
 79         public double YEndPoint
 80         {
 81             get { return this.EndPoint.Y; }
 82             set
 83             {
 84                 yEndPoint = value;
 85                 this.EndPoint = new Point(this.EndPoint.X, yEndPoint);
 86             }
 87         }
 88
 89
 90         private double xPoint;
 91
 92         public double XPoint
 93         {
 94             get { return xPoint; }
 95             set { xPoint = value; }
 96         }
 97
 98         private double yPoint;
 99
100         public double YPoint
101         {
102             get { return yPoint; }
103             set { yPoint = value; }
104         }
105
106
107
108
109         public PathAnimationDemo()
110         {
111             this.SetPoints(this.points);
112             InitializeComponent();
113
114         }
115
116         private void SetPoints(ObservableCollection<Point> myPointCollection)
117         {
118             points.Add(new Point(50, 100));
119             myPointCollection.Add(new Point(100, 50));
120             myPointCollection.Add(new Point(200, 100));
121             myPointCollection.Add(new Point(100, 200));
122             myPointCollection.Add(new Point(400, 400));
123             myPointCollection.Add(new Point(600, 600));
124         }
125
126         public event PropertyChangedEventHandler PropertyChanged;
127
128         private void OnPropertyChanged(string propertyName)
129         {
130             if (PropertyChanged != null)
131             {
132                 PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
133             }
134         }
135
136         private void Button_Click(object sender, RoutedEventArgs e)
137         {
138             this.points.Add(new Point(this.xPoint, this.YPoint));
139             this.Points = this.points;
140         }
141
142     }

绑定元素属性改变不通知界面