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이것은 매우 어리석은 질문 일지 모르지만 코드에 어떤 문제가 있는지 찾으려고합니다.사용자 정의 컨트롤에서 종속성 속성 - WPF
버튼이있는 사용자 정의 컨트롤이 있습니다. DependencyProperty
을 선언했습니다.이 컨트롤은 사용자 컨트롤 내부에있는 단추의 내용에 바인딩됩니다 (예, 이상합니다).
이제 기본 xaml 페이지에서이 사용자 정의 컨트롤의 인스턴스를 2 개 사용하고 종속성 속성이 내 ViewModel의 속성에 바인딩됩니다. 그러나 런타임에 바인딩이 실패합니다.
질문입니다 - 왜 작동하지 않습니까?
코드 :
<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:WpfApplication2="clr-namespace:WpfApplication2" Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<WpfApplication2:UserControl1 NewContent="{Binding CanEnableOne}" Grid.Row="0"/>
<WpfApplication2:UserControl1 NewContent="{Binding CanEnableTwo}" Grid.Row="1"/>
<Button Grid.Row="2" Content="Enable Hello1" Click="OnClickedOne"/>
<Button Grid.Row="3" Content="Enable Hello2" Click="OnClickedTwo"/>
</Grid>
</Window>
public partial class MainWindow : Window
{
ViewModel vm = new ViewModel();
Random r = new Random();
public MainWindow()
{
InitializeComponent();
this.DataContext = vm;
}
private void OnClickedOne(object sender, RoutedEventArgs e)
{
vm.CanEnableOne = r.Next(1,100).ToString();
}
private void OnClickedTwo(object sender, RoutedEventArgs e)
{
vm.CanEnableTwo = r.Next(1, 100).ToString();
}
}
public class ViewModel : INotifyPropertyChanged
{
private string _canEnableOne;
public string CanEnableOne
{
get { return _canEnableOne; }
set
{
if (_canEnableOne == value)
return;
_canEnableOne = value;
InvokePropertyChanged("CanEnableOne");
}
}
private string _canEnableTwo;
public string CanEnableTwo
{
get { return _canEnableTwo; }
set
{
if (_canEnableTwo == value)
return;
_canEnableTwo = value;
InvokePropertyChanged("CanEnableTwo");
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void InvokePropertyChanged(string e)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(e));
}
}
<UserControl x:Class="WpfApplication2.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>
<Button Content="{Binding NewContent}"></Button>
</Grid>
</UserControl>
public partial class UserControl1 : UserControl
{
public UserControl1()
{
InitializeComponent();
}
public static readonly DependencyProperty NewContentProperty =
DependencyProperty.RegisterAttached("NewContent",
typeof (string),
typeof (UserControl1), new PropertyMetadata(new PropertyChangedCallback(PropertyChanged)));
private static void PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
System.Diagnostics.Debug.WriteLine("Hello");
}
public string NewContent
{
get { return (string)GetValue(NewContentProperty); }
set { SetValue(NewContentProperty, value); }
}
}
Error:System.Windows.Data Error: 39 : BindingExpression path error: 'NewContent' property not found on 'object' ''ViewModel' (HashCode=23172649)'. BindingExpression:Path=NewContent; DataItem='ViewModel' (HashCode=23172649); target element is 'Button' (Name=''); target property is 'Content' (type 'Object')
System.Windows.Data Error: 39 : BindingExpression path error: 'NewContent' property not found on 'object' ''ViewModel' (HashCode=23172649)'. BindingExpression:Path=NewContent; DataItem='ViewModel' (HashCode=23172649); target element is 'Button' (Name=''); target property is 'Content' (type 'Object')