這個問題一般出現在Triggers中Property指定的類型為Nullable。 解決辦法就是用DataTrigger代替Trigger， 然后用Binding+Converter轉換為具體非Null值。 比如： <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> 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; ?????????? } ?????? }