我在 WPF 中使用
BooleanToVisibilityConverterVisibilityBooleantruefalse您可以使用通用的
IValueConverterpublic class BooleanConverter<T> : IValueConverter
{
public BooleanConverter(T trueValue, T falseValue)
{
True = trueValue;
False = falseValue;
}
public T True { get; set; }
public T False { get; set; }
public virtual object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return value is bool && ((bool) value) ? True : False;
}
public virtual object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return value is T && EqualityComparer<T>.Default.Equals((T) value, True);
}
}
接下来，将其子类化，其中
TVisibilitypublic sealed class BooleanToVisibilityConverter : BooleanConverter<Visibility>
{
public BooleanToVisibilityConverter() :
base(Visibility.Visible, Visibility.Collapsed) {}
}
最后，您可以在 XAML 中使用上面的
BooleanToVisibilityConverterCollapsedVisible<Application.Resources>
<app:BooleanToVisibilityConverter
x:Key="BooleanToVisibilityConverter"
True="Collapsed"
False="Visible" />
</Application.Resources>
当您想要绑定到名为
IsHiddenIsVisible自己编写是目前最好的解决方案。这是一个可以执行正常和反转两种方式的转换器的示例。如果您对此有任何问题，请询问。
[ValueConversion(typeof(bool), typeof(Visibility))]
public class InvertableBooleanToVisibilityConverter : IValueConverter
{
enum Parameters
{
Normal, Inverted
}
public object Convert(object value, Type targetType,
object parameter, CultureInfo culture)
{
var boolValue = (bool)value;
var direction = (Parameters)Enum.Parse(typeof(Parameters), (string)parameter);
if(direction == Parameters.Inverted)
return !boolValue? Visibility.Visible : Visibility.Collapsed;
return boolValue? Visibility.Visible : Visibility.Collapsed;
}
public object ConvertBack(object value, Type targetType,
object parameter, CultureInfo culture)
{
return null;
}
}
<UserControl.Resources>
<Converters:InvertableBooleanToVisibilityConverter x:Key="_Converter"/>
</UserControl.Resources>
<Button Visibility="{Binding IsRunning, Converter={StaticResource _Converter}, ConverterParameter=Inverted}">Start</Button>
using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;
public sealed class BooleanToVisibilityConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var flag = false;
if (value is bool)
{
flag = (bool)value;
}
else if (value is bool?)
{
var nullable = (bool?)value;
flag = nullable.GetValueOrDefault();
}
if (parameter != null)
{
if (bool.Parse((string)parameter))
{
flag = !flag;
}
}
if (flag)
{
return Visibility.Visible;
}
else
{
return Visibility.Collapsed;
}
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
var back = ((value is Visibility) && (((Visibility)value) == Visibility.Visible));
if (parameter != null)
{
if ((bool)parameter)
{
back = !back;
}
}
return back;
}
}
然后传递 true 或 false 作为 ConverterParameter
<Grid.Visibility>
<Binding Path="IsYesNoButtonSetVisible" Converter="{StaticResource booleanToVisibilityConverter}" ConverterParameter="true"/>
</Grid.Visibility>
将 ViewModel 布尔值 (IsButtonVisible) 与 xaml 控件可见性属性绑定的另一种方法。 无需编码，无需转换，只需样式设计。
<Style TargetType={x:Type Button} x:Key="HideShow">
<Style.Triggers>
<DataTrigger Binding="{Binding IsButtonVisible}" Value="False">
<Setter Property="Visibility" Value="Hidden"/>
</DataTrigger>
</Style.Triggers>
</Style>
<Button Style="{StaticResource HideShow}">Hello</Button>
实现您自己的 IValueConverter 实现。示例实现位于
http://msdn.microsoft.com/en-us/library/system.windows.data.ivalueconverter.aspx
在您的 Convert 方法中，让它返回您想要的值而不是默认值。
Codeplex 上还有 WPF Converters 项目。在他们的文档中，他们说您可以使用他们的 MapConverter 将 Visibility 枚举转换为 bool
<Label>
<Label.Visible>
<Binding Path="IsVisible">
<Binding.Converter>
<con:MapConverter>
<con:Mapping From="True" To="{x:Static Visibility.Visible}"/>
<con:Mapping From="False" To="{x:Static Visibility.Hidden}"/>
</con:MapConverter>
</Binding.Converter>
</Binding>
</Label.Visible>
</Label>
或者真正的懒人方法，只需利用已有的并翻转它：
public class InverseBooleanToVisibilityConverter : IValueConverter
{
private BooleanToVisibilityConverter _converter = new BooleanToVisibilityConverter();
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var result = _converter.Convert(value, targetType, parameter, culture) as Visibility?;
return result == Visibility.Collapsed ? Visibility.Visible : Visibility.Collapsed;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var result = _converter.ConvertBack(value, targetType, parameter, culture) as bool?;
return result == true ? false : true;
}
}
如果您不喜欢编写自定义转换器，您可以使用数据触发器来解决此问题：
<Style.Triggers>
<DataTrigger Binding="{Binding YourBinaryOption}" Value="True">
<Setter Property="Visibility" Value="Visible" />
</DataTrigger>
<DataTrigger Binding="{Binding YourBinaryOption}" Value="False">
<Setter Property="Visibility" Value="Collapsed" />
</DataTrigger>
</Style.Triggers>
我刚刚就此发表了一篇文章。我使用了与 Michael Hohlios 类似的想法。只是，我使用了属性而不是使用“对象参数”。
将可见性绑定到 WPF 中的 bool 值
在我看来，使用属性使其更具可读性。
<local:BoolToVisibleOrHidden x:Key="BoolToVisConverter" Collapse="True" Reverse="True" />
这是我写的并且经常使用的一个。它使用一个布尔转换器参数来指示是否反转该值，然后使用 XOR 来执行求反：
[ValueConversion(typeof(bool), typeof(System.Windows.Visibility))]
public class BooleanVisibilityConverter : IValueConverter
{
System.Windows.Visibility _visibilityWhenFalse = System.Windows.Visibility.Collapsed;
/// <summary>
/// Gets or sets the <see cref="System.Windows.Visibility"/> value to use when the value is false. Defaults to collapsed.
/// </summary>
public System.Windows.Visibility VisibilityWhenFalse
{
get { return _visibilityWhenFalse; }
set { _visibilityWhenFalse = value; }
}
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
bool negateValue;
Boolean.TryParse(parameter as string, out negateValue);
bool val = negateValue ^ System.Convert.ToBoolean(value); //Negate the value when negateValue is true using XOR
return val ? System.Windows.Visibility.Visible : _visibilityWhenFalse;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
bool negateValue;
Boolean.TryParse(parameter as string, out negateValue);
if ((System.Windows.Visibility)value == System.Windows.Visibility.Visible)
return true ^ negateValue;
else
return false ^ negateValue;
}
}
这里有一个异或真值表供参考：
XOR
x y XOR
---------
0 0 0
0 1 1
1 0 1
1 1 0
与其编写自己的代码/重新发明，不如考虑使用 CalcBinding:
// Automatic two way convertion of bool expression to Visibility and
// back if target property has such type: description
<Button Visibility="{c:Binding !IsChecked}" />
<Button Visibility="{c:Binding IsChecked, FalseToVisibility=Hidden}" />
CalcBinding 对于许多其他场景也非常有用。
我正在寻找更通用的答案，但找不到。我编写了一个可能对其他人有帮助的转换器。
基于这样的事实，我们需要区分六种不同的情况：
这是我对前 4 个案例的实现：
[ValueConversion(typeof(bool), typeof(Visibility))]
public class BooleanToVisibilityConverter : IValueConverter
{
enum Types
{
/// <summary>
/// True to Visible, False to Collapsed
/// </summary>
t2v_f2c,
/// <summary>
/// True to Visible, False to Hidden
/// </summary>
t2v_f2h,
/// <summary>
/// True to Collapsed, False to Visible
/// </summary>
t2c_f2v,
/// <summary>
/// True to Hidden, False to Visible
/// </summary>
t2h_f2v,
}
public object Convert(object value, Type targetType,
object parameter, CultureInfo culture)
{
var b = (bool)value;
string p = (string)parameter;
var type = (Types)Enum.Parse(typeof(Types), (string)parameter);
switch (type)
{
case Types.t2v_f2c:
return b ? Visibility.Visible : Visibility.Collapsed;
case Types.t2v_f2h:
return b ? Visibility.Visible : Visibility.Hidden;
case Types.t2c_f2v:
return b ? Visibility.Collapsed : Visibility.Visible;
case Types.t2h_f2v:
return b ? Visibility.Hidden : Visibility.Visible;
}
throw new NotImplementedException();
}
public object ConvertBack(object value, Type targetType,
object parameter, CultureInfo culture)
{
var v = (Visibility)value;
string p = (string)parameter;
var type = (Types)Enum.Parse(typeof(Types), (string)parameter);
switch (type)
{
case Types.t2v_f2c:
if (v == Visibility.Visible)
return true;
else if (v == Visibility.Collapsed)
return false;
break;
case Types.t2v_f2h:
if (v == Visibility.Visible)
return true;
else if (v == Visibility.Hidden)
return false;
break;
case Types.t2c_f2v:
if (v == Visibility.Visible)
return false;
else if (v == Visibility.Collapsed)
return true;
break;
case Types.t2h_f2v:
if (v == Visibility.Visible)
return false;
else if (v == Visibility.Hidden)
return true;
break;
}
throw new InvalidOperationException();
}
}
示例：
Visibility="{Binding HasItems, Converter={StaticResource BooleanToVisibilityConverter}, ConverterParameter='t2v_f2c'}"
我认为参数很容易记住。
希望它对某人有帮助。
您可以使用QuickConverter。
使用 QuickConverter，您可以编写与 BindingExpression 内联的转换器逻辑
这是一个反转的 BooleanToVisibility 转换器：
Visibility="{qc:Binding '!$P ? Visibility.Visible : Visibility.Collapsed', P={Binding Example}}"
您可以通过 NuGet 添加 QuickConverter。 查看设置文档。 链接：https://quickconverter.codeplex.com/
编写您自己的转换。
public class ReverseBooleanToVisibilityConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
// your converter code here
}
}
一个简单的单向版本，可以像这样使用：
Visibility="{Binding IsHidden, Converter={x:Static Ui:Converters.BooleanToVisibility}, ConverterParameter=true}
可以这样实现：
public class BooleanToVisibilityConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var invert = false;
if (parameter != null)
{
invert = Boolean.Parse(parameter.ToString());
}
var booleanValue = (bool) value;
return ((booleanValue && !invert) || (!booleanValue && invert))
? Visibility.Visible : Visibility.Collapsed;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
将所有内容转换为所有内容（布尔、字符串、枚举等）：
public class EverythingConverterValue
{
public object ConditionValue { get; set; }
public object ResultValue { get; set; }
}
public class EverythingConverterList : List<EverythingConverterValue>
{
}
public class EverythingConverter : IValueConverter
{
public EverythingConverterList Conditions { get; set; } = new EverythingConverterList();
public object NullResultValue { get; set; }
public object NullBackValue { get; set; }
public object Convert(object value, Type targetType,
object parameter, CultureInfo culture)
{
return Conditions.Where(x => x.ConditionValue.Equals(value)).Select(x => x.ResultValue).FirstOrDefault() ?? NullResultValue;
}
public object ConvertBack(object value, Type targetType,
object parameter, CultureInfo culture)
{
return Conditions.Where(x => x.ResultValue.Equals(value)).Select(x => x.ConditionValue).FirstOrDefault() ?? NullBackValue;
}
}
XAML 示例：
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:conv="clr-namespace:MvvmGo.Converters;assembly=MvvmGo.WindowsWPF"
xmlns:sys="clr-namespace:System;assembly=mscorlib">
<conv:EverythingConverter x:Key="BooleanToVisibilityConverter">
<conv:EverythingConverter.Conditions>
<conv:EverythingConverterValue ResultValue="{x:Static Visibility.Visible}">
<conv:EverythingConverterValue.ConditionValue>
<sys:Boolean>True</sys:Boolean>
</conv:EverythingConverterValue.ConditionValue>
</conv:EverythingConverterValue>
<conv:EverythingConverterValue ResultValue="{x:Static Visibility.Collapsed}">
<conv:EverythingConverterValue.ConditionValue>
<sys:Boolean>False</sys:Boolean>
</conv:EverythingConverterValue.ConditionValue>
</conv:EverythingConverterValue>
</conv:EverythingConverter.Conditions>
</conv:EverythingConverter>
<conv:EverythingConverter x:Key="InvertBooleanToVisibilityConverter">
<conv:EverythingConverter.Conditions>
<conv:EverythingConverterValue ResultValue="{x:Static Visibility.Visible}">
<conv:EverythingConverterValue.ConditionValue>
<sys:Boolean>False</sys:Boolean>
</conv:EverythingConverterValue.ConditionValue>
</conv:EverythingConverterValue>
<conv:EverythingConverterValue ResultValue="{x:Static Visibility.Collapsed}">
<conv:EverythingConverterValue.ConditionValue>
<sys:Boolean>True</sys:Boolean>
</conv:EverythingConverterValue.ConditionValue>
</conv:EverythingConverterValue>
</conv:EverythingConverter.Conditions>
</conv:EverythingConverter>
<conv:EverythingConverter x:Key="MarriedConverter" NullResultValue="Single">
<conv:EverythingConverter.Conditions>
<conv:EverythingConverterValue ResultValue="Married">
<conv:EverythingConverterValue.ConditionValue>
<sys:Boolean>True</sys:Boolean>
</conv:EverythingConverterValue.ConditionValue>
</conv:EverythingConverterValue>
<conv:EverythingConverterValue ResultValue="Single">
<conv:EverythingConverterValue.ConditionValue>
<sys:Boolean>False</sys:Boolean>
</conv:EverythingConverterValue.ConditionValue>
</conv:EverythingConverterValue>
</conv:EverythingConverter.Conditions>
<conv:EverythingConverter.NullBackValue>
<sys:Boolean>False</sys:Boolean>
</conv:EverythingConverter.NullBackValue>
</conv:EverythingConverter>
正如 Zamir 在 OP 评论中指出的那样，如果要绑定到视图模型，到目前为止最简单的方法是创建另一个属性来绑定，这样可以反转布尔值；
public bool IsSending { get; set; }
public bool IsNotSending => !IsSending;
这是以绑定到底层模型为条件的。
注意： 为了简洁起见，我省略了
INotifyPropertyChanged我知道这已经过时了，但是，您不需要重新实现任何内容。
我所做的就是像这样否定财产的价值：
<!-- XAML code -->
<StackPanel Name="x" Visibility="{Binding Path=Specials, ElementName=MyWindow, Converter={StaticResource BooleanToVisibilityConverter}}"></StackPanel>
<StackPanel Name="y" Visibility="{Binding Path=NotSpecials, ElementName=MyWindow, Converter={StaticResource BooleanToVisibilityConverter}}"></StackPanel>
....
//Code behind
public bool Specials
{
get { return (bool) GetValue(SpecialsProperty); }
set
{
NotSpecials= !value;
SetValue(SpecialsProperty, value);
}
}
public bool NotSpecials
{
get { return (bool) GetValue(NotSpecialsProperty); }
set { SetValue(NotSpecialsProperty, value); }
}
而且效果很好！
我错过了什么吗？