Question

我使用提供的xmal代码和c＃代码得到以下异常。请帮忙。

异常：无法转换类型＆＃39; MS.Internal.NamedObject＆＃39;输入＆＃39; System.IConvertible＆＃39;

XAML代码：

    <Grid x:Name="cheque1" Width="500" HorizontalAlignment="Left" Margin="{DynamicResource Cheque1Position}" Height="200" VerticalAlignment="Top" d:LayoutOverrides="Height">
        <Grid.Visibility>
            <MultiBinding Converter="{StaticResource ChequeVisibilityConverter}" ConverterParameter="0" diag:PresentationTraceSources.TraceLevel="None">
                <Binding Path="_ItemDASFlowExtensions.DepositSummary.ScannedCheques"/>
                <Binding Path="_Common.DynamicIndex" />
            </MultiBinding>
        </Grid.Visibility>
        <Image x:Name="ChequeToBeReturned1" HorizontalAlignment="Right" Height="60" VerticalAlignment="Top" Width="76" Style="{DynamicResource ReturnCheque}" Margin="0,5,5,0">
            <Image.Visibility>
                <MultiBinding Converter="{StaticResource ChequeVisibilityConverter}" ConverterParameter="0, Validity" diag:PresentationTraceSources.TraceLevel="High">
                    <Binding Path="_ItemDASFlowExtensions.DepositSummary.ScannedCheques"/>
                    <Binding Path="_Common.DynamicIndex" />
                </MultiBinding>
            </Image.Visibility>
        </Image>
    </Grid>

C＃转换器代码：

public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{   
    Visibility visibility = Visibility.Hidden;
    IList<IChequeMediaItem> array = values[0] as IList<IChequeMediaItem>;
    int dynIndex =-1 ;
    if (values[1]!=null)
    {               
        dynIndex = System.Convert.ToInt32(values[1]);
    } 
}

我在语句

处获得InvalidCastException

dynIndex = System.Convert.ToInt32(values[1]);

Answer 1

_Common.DynamicIndex未正确设置或绑定错误。在转换器中，它返回DependencyProperty.UnsetValue，相当于null。

转换器类很好，检查绑定是否正确完成并检查运行时该值是否为空。

无法转换类型＆＃39; MS.Internal.NamedObject＆＃39;键入＆＃39; System.IConvertible＆＃39;

C＃转换器代码：

1 个答案: