WPF错误:必须使“Property”具有非 null 值。
时间:2017-06-18 14:11:37
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这个问题一般出如今Triggers中Property指定的类型为Nullable。
解决的方法就是用DataTrigger取代Trigger, 然后用Binding+Converter转换为详细非Null值。
比方:
<Style x:Key="DisableStyle" TargetType="Button">
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding ElementName=ckb1, Path=IsChecked, Converter={StaticResource NullableToBooleanConverter}}" Value="true"></Condition>
<Condition Binding="{Binding ElementName=ckb2, Path=IsChecked, Converter={StaticResource NullableToBooleanConverter}}" Value="true"></Condition>
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="False"></Setter>
</MultiDataTrigger>
</Style.Triggers>
</Style>
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding ElementName=ckb1, Path=IsChecked, Converter={StaticResource NullableToBooleanConverter}}" Value="true"></Condition>
<Condition Binding="{Binding ElementName=ckb2, Path=IsChecked, Converter={StaticResource NullableToBooleanConverter}}" Value="true"></Condition>
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="False"></Setter>
</MultiDataTrigger>
</Style.Triggers>
</Style>
NullableToBooleanConverter:
public object Convert( object value , Type targetType, object parameter, CultureInfo culture )
{
Nullable<bool > isCheck = value as Nullable< bool>;
if (null == isCheck)
{
return false ;
}
else
{
return isCheck .Value;
}
}
原文:http://www.cnblogs.com/claireyuancy/p/7044090.html
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