一种依赖性 属性 更改通知的方式
One way dependency property changed notification
我正在尝试创建一个具有依赖性的用户控件 属性。当从用户控件外部更改依赖项 属性 时,我需要执行某些逻辑,但是当从用户控件内部更改依赖项 属性 时,不应执行该逻辑。我有这个小样本。我只想在从主窗口设置值时执行某些逻辑,而不是在通过单击复选框设置值时执行。我不知道 PropertyChangedCallback
是否正确,但这是我的方法。
用户控件:
public partial class UserControl1 : UserControl
{
public int MyProperty
{
get { return (int)GetValue(MyPropertyProperty); }
set { SetValue(MyPropertyProperty, value); }
}
public static readonly DependencyProperty MyPropertyProperty =
DependencyProperty.Register("MyProperty", typeof(int), typeof(UserControl1), new PropertyMetadata(new PropertyChangedCallback(OnPropertyChanged)));
private static void OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
// Only process the 5, don't process the 6
}
public UserControl1()
{
InitializeComponent();
}
private void checkBox_Click(object sender, RoutedEventArgs e)
{
MyProperty = 6;
}
}
用户控件xaml:
<UserControl x:Class="WpfApplication4.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">
<Grid>
<CheckBox x:Name="checkBox" Click="checkBox_Click"/>
</Grid>
</UserControl>
主窗口:
public partial class MainWindow : Window
{
public int MainWindowProperty { get; set; }
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
MainWindowProperty = 5;
}
}
主窗口xaml:
<Window x:Class="WpfApplication4.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication4"
Title="MainWindow" Height="350" Width="525">
<Grid>
<local:UserControl1 MyProperty="{Binding MainWindowProperty}"/>
</Grid>
</Window>
private static void OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (!disableProcessing)
{
// Only process the 5, don't process the 6
}
}
bool disableProcessing = false;
private void checkBox_Click(object sender, RoutedEventArgs e)
{
disableProcessing = true;
MyProperty = 6;
disableProcessing = false;
}
我正在尝试创建一个具有依赖性的用户控件 属性。当从用户控件外部更改依赖项 属性 时,我需要执行某些逻辑,但是当从用户控件内部更改依赖项 属性 时,不应执行该逻辑。我有这个小样本。我只想在从主窗口设置值时执行某些逻辑,而不是在通过单击复选框设置值时执行。我不知道 PropertyChangedCallback
是否正确,但这是我的方法。
用户控件:
public partial class UserControl1 : UserControl
{
public int MyProperty
{
get { return (int)GetValue(MyPropertyProperty); }
set { SetValue(MyPropertyProperty, value); }
}
public static readonly DependencyProperty MyPropertyProperty =
DependencyProperty.Register("MyProperty", typeof(int), typeof(UserControl1), new PropertyMetadata(new PropertyChangedCallback(OnPropertyChanged)));
private static void OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
// Only process the 5, don't process the 6
}
public UserControl1()
{
InitializeComponent();
}
private void checkBox_Click(object sender, RoutedEventArgs e)
{
MyProperty = 6;
}
}
用户控件xaml:
<UserControl x:Class="WpfApplication4.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">
<Grid>
<CheckBox x:Name="checkBox" Click="checkBox_Click"/>
</Grid>
</UserControl>
主窗口:
public partial class MainWindow : Window
{
public int MainWindowProperty { get; set; }
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
MainWindowProperty = 5;
}
}
主窗口xaml:
<Window x:Class="WpfApplication4.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication4"
Title="MainWindow" Height="350" Width="525">
<Grid>
<local:UserControl1 MyProperty="{Binding MainWindowProperty}"/>
</Grid>
</Window>
private static void OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (!disableProcessing)
{
// Only process the 5, don't process the 6
}
}
bool disableProcessing = false;
private void checkBox_Click(object sender, RoutedEventArgs e)
{
disableProcessing = true;
MyProperty = 6;
disableProcessing = false;
}