public FunTurnValToolBox()
{
InitializeComponent();
this.DataContext = this;
TurnValCommand = new DelegateCommand<string>(s => {
if (s == "UP")
{
if (TurnValue < TurnMaxValue)
TurnValue += 1;
}
else
{
if (TurnValue > TurnMinValue)
{
TurnValue -= 1;
}
}
});
}
public static readonly DependencyProperty TurnValueProperty = DependencyProperty.Register("TurnValue", typeof(int), typeof(FunTurnValToolBox), new FrameworkPropertyMetadata()
{
PropertyChangedCallback = OnDemoChanged,
BindsTwoWayByDefault = true
});
public int TurnValue
{
get
{
return (int)GetValue(TurnValueProperty);
}
set
{
SetValue(TurnValueProperty,value);
}
}
private static void OnDemoChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.OldValue != e.NewValue)
{
//邏輯處理
}
}
public static DependencyProperty TurnMaxValueProperty = DependencyProperty.Register("TurnMaxValue", typeof(int), typeof(FunTurnValToolBox), new FrameworkPropertyMetadata(100)
{
PropertyChangedCallback = OnDemoChanged,
BindsTwoWayByDefault = true
});
public int TurnMaxValue
{
get
{
return (int)GetValue(TurnMaxValueProperty);
}
set
{
SetValue(TurnMaxValueProperty, value);
}
}
public static DependencyProperty TurnMinValueProperty = DependencyProperty.Register("TurnMinValue", typeof(int), typeof(FunTurnValToolBox), new FrameworkPropertyMetadata(0)
{
PropertyChangedCallback = OnDemoChanged,
BindsTwoWayByDefault = true
});
public int TurnMinValue
{
get
{
return (int)GetValue(TurnMinValueProperty);
}
set
{
SetValue(TurnMinValueProperty, value);
}
}
下面是另一個UserControl中的應用(部分代碼),此時已經設定了UserControl的DataContext為自己定義的ViewModel,并且自定義的ViewModel已經實作了INotifyPropertyChanged接口。
<Grid Margin="0,0,0,10">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Grid Grid.Column="0">
<TextBlock Text="行高" FontSize="14" Foreground="{StaticResource Normal.FontColor}" VerticalAlignment="Center" Padding="5" />
</Grid>
<Grid Grid.Column="1">
<local:FunTurnValToolBox TurnValue="{Binding FontLineHeight,Mode=TwoWay}" TurnMinValue="0" TurnMaxValue="80" Width="Auto" Height="Auto" x:Name="FTVB" />
</Grid>
</Grid>
問題:自定義的控件的依賴屬性再綁定viewmodel的屬性時無法生效,這是什麼問題,求大神指教!
今天進行補充更新,問題已經得到解決!解決方案如下:
1.将引入的viewmodle設定成DataContext之後,加上名稱(例如 x:Name=“TPB”)
<UserControl.DataContext>
<local:TextPropertyToolBoxModel x:Name="TPB" />
</UserControl.DataContext>
2.将自定義控件(FunTurnValToolBox)的依賴屬性(TurnValue)通過如下方式進行綁定即可
3.補充:其他部落客說的修改自定義控件的依賴屬性預設的 BindingMode為TwoWay其實沒有任何關系,如下所示定義依賴屬性依舊可以成功
public static readonly DependencyProperty TurnValueProperty = DependencyProperty.Register("TurnValue", typeof(int), typeof(FunTurnValToolBox));
public int TurnValue
{
get
{
return (int)GetValue(TurnValueProperty);
}
set
{
SetValue(TurnValueProperty,value);
}
}