>我正在尝试将 XAML 中的某些属性与枚举类型绑定。它应该如何工作:我在菜单栏中有一些单选按钮,用于设置我的枚举值。并且这个枚举值在Grid
中设置isEnabled
属性。所以有一个关系:单选按钮->(EnumToBooleanConverter)->枚举对象->(EnumToIsActiveCnoverter)-> isEnabled
属性。我编写了两个转换器来执行该绑定。法典:
<Window.Resources>
<local:EnumToBooleanConverter x:Key="actionConverter" />
<local:EnumToIsActiveConverter x:Key="activityConverter" />
</Window.Resources>
。
<MenuItem Header="Settings">
<MenuItem Header="Action">
<MenuItem Header="Draw">
<MenuItem.Icon>
<RadioButton GroupName="MenuActionButton"
IsChecked="{Binding Path=appMode,
Converter={StaticResource actionConverter},
ConverterParameter={x:Static local:ApplicationMode.Draw}}"/>
</MenuItem.Icon>
</MenuItem>
<MenuItem Header="Edit">
<MenuItem.Icon>
<RadioButton GroupName="MenuActionButton"
IsChecked="{Binding Path=appMode,
Converter={StaticResource actionConverter},
ConverterParameter={x:Static local:ApplicationMode.Edit}}"/>
</MenuItem.Icon>
</MenuItem>
<MenuItem Header="Constraints">
<MenuItem.Icon>
<RadioButton GroupName="MenuActionButton"
IsChecked="{Binding Path=appMode,
Converter={StaticResource actionConverter},
ConverterParameter={x:Static local:ApplicationMode.Constraints}}"/>
</MenuItem.Icon>
</MenuItem>
</MenuItem>
</MenuItem>
CS 文件:
public partial class MainWindow : Window
{
public ApplicationMode appMode { get; set; }
public MainWindow()
{
this.appMode = ApplicationMode.Draw;
InitializeComponent();
}
}
public class EnumToBooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
//return value.Equals(parameter);
return null;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return value.Equals(true) ? parameter : Binding.DoNothing;
}
}
public class EnumToIsActiveConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return value.Equals(parameter);
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
//return value.Equals(true) ? parameter : Binding.DoNothing;
return Binding.DoNothing;
}
}
public enum ApplicationMode
{
Draw,
Edit,
Constraints
}
EnumToBooleanConverter
选中单选按钮时将枚举值更改为给定参数,EnumToIsActiveConverter
当枚举值设置为给定参数时isEnabled
更改给定元素的属性。在我看来,它应该工作得很好。我在这里错过了什么?
更简单的解决方案,没有单选按钮:
a. 对图标作业使用"菜单项可检查"功能,并将"已检查"绑定到 appMode 属性:
<MenuItem Header="Action">
<MenuItem Header="Draw" IsCheckable="True"
IsChecked="{Binding Path=appMode,
Converter={StaticResource actionConverter},
ConverterParameter={x:Static local:ApplicationMode.Draw}}" />
<MenuItem Header="Edit" IsCheckable="True"
IsChecked="{Binding Path=appMode,
Converter={StaticResource actionConverter},
ConverterParameter={x:Static local:ApplicationMode.Edit}}" />
</MenuItem>
b.b. 在代码中,更改属性以触发属性更改事件:
public partial class MainWindow : Window, INotifyPropertyChanged
{
private ApplicationMode _appMode;
public ApplicationMode appMode
{
get { return _appMode; }
set
{
_appMode = value;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(appMode)));
}
}
public MainWindow()
{
this.appMode = ApplicationMode.Draw;
InitializeComponent();
}
public event PropertyChangedEventHandler PropertyChanged;
}
c.在转换器中修复转换回模板:
public class EnumToBooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return value.Equals(parameter);
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return parameter;
}
}
您正在使用RadioButton
控件,但仅作为指示器。
因此,单击该项不会更改属性值,因为只有MenuItem
接收单击,而不是单选按钮。
这也有点浪费,因为对于 V(当前活动指示),您不需要单选按钮控件,相当具有可见性绑定的路径。
我将以现有方式为您提供解决方案:
a. 将 Click 事件添加到每个菜单项
b. 将相关的值放在 Tag 属性中(这是为了事件的简单性,如您所见)
c. 添加到 MainWindow 类实现INotifyPropertyChanged
接口以降低 XAML 了解 appMode 模式。
下面是代码 XAML:
<MenuItem Header="Draw" Click="MenuItem_Click" Tag="{x:Static local:ApplicationMode.Draw}" >
<MenuItem.Icon>
<RadioButton GroupName="MenuActionButton"
IsChecked="{Binding Path=appMode,
Converter={StaticResource actionConverter},
ConverterParameter={x:Static local:ApplicationMode.Draw}}"/>
</MenuItem.Icon>
</MenuItem>
<MenuItem Header="Edit" Click="MenuItem_Click" Tag="{x:Static local:ApplicationMode.Edit}">
<MenuItem.Icon>
<RadioButton GroupName="MenuActionButton"
IsChecked="{Binding Path=appMode,
Converter={StaticResource actionConverter},
ConverterParameter={x:Static local:ApplicationMode.Edit}}"/>
</MenuItem.Icon>
</MenuItem>
点击事件MenuItem_Click:
public event PropertyChangedEventHandler PropertyChanged;
private void MenuItem_Click(object sender, RoutedEventArgs e)
{
var item = (MenuItem)sender;
appMode = (ApplicationMode) item.Tag;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(appMode)));
}