正常定义的以来属性,在XAML里设置值得时候是不触发Setter的,只能在code中用。
监听PropertyChangedCallback事件可以感知XAML里的设置,这样才能code和XAML配合使用。
http://*.com/questions/5644081/wpf-usercontrol-dependency-property-setter-not-triggering
http://*.com/questions/5644081/wpf-usercontrol-dependency-property-setter-not-triggering
<UserControl x:Class="WpfApplication1.UserControl1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300" Background="Black"> <Grid> <Button Name="b" Content="Button" Margin="27,26,0,0" Click="b_Click" Height="22" VerticalAlignment="Top" HorizontalAlignment="Left" Width="75"/> </Grid> </UserControl>
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; namespace WpfApplication1 { /// <summary> /// UserControl1.xaml の相互作用ロジック /// </summary> public partial class UserControl1 : UserControl { public UserControl1() { InitializeComponent(); } public static readonly DependencyProperty IsAAAProperty = DependencyProperty.Register( "IsAAA", typeof(Boolean), typeof(UserControl1), new FrameworkPropertyMetadata(new PropertyChangedCallback(OnUriChanged) ) ); private static void OnUriChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { if ((bool)e.NewValue == true) { UserControl1 u = (UserControl1)d; u.b.Background = Brushes.Black; } MessageBox.Show("event"); } public bool IsAAA { get { MessageBox.Show("get"); return (bool)GetValue(IsAAAProperty); } set { MessageBox.Show("set"); SetValue(IsAAAProperty, value); } } private void b_Click(object sender, RoutedEventArgs e) { } } }
The correct way of implementing a source for an Image in a user control in my opinion is not BitmapSouce. The easiest and best way (according to me again) is using Uri.
Change your dependency property to this (while also defining a change callback event):
ImageSourceProperty = DependencyProperty.Register(
"ImageSource", typeof (Uri), typeof (MyButton),
new FrameworkPropertyMetadata(new PropertyChangedCallback(OnImageSourceChanged)));
and the property to this:
public Uri ImageSource
{
get
{
return (Uri)GetValue(ImageSourceProperty);
}
set
{
SetValue(ImageSourceProperty, value);
}
}
Where your call back is like this:
private static void OnImageSourceChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
MyButton hsb = (MyButton)sender;
Image image = hsb.tehImage;
image.Source = new BitmapImage((Uri) e.NewValue);
}