WPF 文本多重绑定

Question

当我使用多重绑定时，转换器无法收集

public partial class TestControl : UserControl
{
     public TestClass TimeData{get;set;}
     public TestControl ()
     {
        InitializeComponent();
     }
}
public class TestClass
{
        public int DelayTime { get; set; } = 80;
}

当我使用此代码时，textblock.Text 将是 80_80。

<Grid DataContext="{Binding TimeData, ElementName=userControl, Mode=OneWay}">
     <TextBlock Grid.Row="1">
          <TextBlock.Text>
               <MultiBinding StringFormat="{}{0}_{1}">
                     <Binding Path="DelayTime"/>
                     <Binding Path="DelayTime"/>
               </MultiBinding>
          </TextBlock.Text>
     </TextBlock>
</Grid>

但是当我添加转换器时，它不起作用 object[] 值为 0,0;

<Grid DataContext="{Binding TimeData, ElementName=userControl, Mode=OneWay}">
     <TextBlock Grid.Row="1">
          <TextBlock.Text>
               <MultiBinding Converter="{StaticResource MultiflyConverter}">
                     <Binding Path="DelayTime"/>
                     <Binding Path="DelayTime"/>
               </MultiBinding>
          </TextBlock.Text>
     </TextBlock>
</Grid>

public class MultiflyConverter : IMultiValueConverter
{
     public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var a = System.Convert.ToInt32(values[0]);
            var b = System.Convert.ToInt32(values[1]);
            return a * b;
        }
     public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

我该如何修复它？

Answer 1

在没有看到完整代码的情况下，很难准确说出错误原因。
但我可以假设这是可能的，因为转换不正确。 要实现类似于 Binding 中类型转换的转换，需要使用 TypeConveter。
示例：

    /// <summary>A converter that converts all values into Int32 numbers
    /// and returns the result of their multiplication.</summary>
    public class MultiflyConverter : IMultiValueConverter
    {
        private readonly Int32Converter converter = new Int32Converter();
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            int result = 1;
            foreach (var value in values)
            {
                if (value is not int num)
                {
                    if (converter.IsValid(value))
                    {
                        num = (int)converter.ConvertFrom(value)!;
                    }
                    else
                    {
                        continue;
                    }
                }
                result *= num;
            }
            return result.ToString();
        }
        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }