wpf - TextBlock: Binding of Text and StringFormat

Question

Is it possible to bind Text and StringFormat too?

<TextBlock Text="{Binding Path=Price, StringFormat={Binding Path=DecimalPoints}}" />

DecimalPoints is constantly changing from F0 to F15. Unfortunatelly the code above doesn't compile.

Answer 1

我认为您最好的选择绝对是转换器。然后您的绑定将如下所示：

<TextBlock.Text>
   <MultiBinding Converter="{StaticResource StringFormatConverter }">
      <Binding Path="Price"/>
      <Binding Path="DecimalPoints"/>
   </MultiBinding>
</TextBlock.Text>

然后是一个快速转换器（你当然可以让它更好，但这是一般的想法）。

    public class StringFormatConverter : IMultiValueConverter
    {
      #region IMultiValueConverter Members

      public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
      {
          double number = (double)values[0];
          string format = "f" + ((int)values[1]).ToString();
          return number.ToString(format);
      }

      public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
      {
        throw new NotImplementedException();
      }

      #endregion
    }

Answer 2

正如@Sheridan 提到的，在这种情况下，Binding将不起作用。但是您可以使用静态字符串创建一个类，并在 XAML 中引用它们。语法是：

<x:Static Member="prefix : typeName . staticMemberName" .../>

下面是一个例子：

XAML

xmlns:local="clr-namespace:YourNameSpace"
xmlns:sys="clr-namespace:System;assembly=mscorlib"

<Grid>
    <TextBlock Text="{Binding Source={x:Static sys:DateTime.Now}, StringFormat={x:Static Member=local:StringFormats.DateFormat}}" 
               HorizontalAlignment="Right" />

    <TextBlock Text="{Binding Source={x:Static sys:DateTime.Now}, StringFormat={x:Static Member=local:StringFormats.Time}}" />
</Grid>

Code behind

public class StringFormats 
{
    public static string DateFormat = "Date: {0:dddd}";

    public static string Time = "Time: {0:HH:mm}";
}   

欲了解更多信息，请参阅：

x:MSDN 上的静态标记扩展

Answer 3

不，你不能......原因是因为你只能绑定到 aDependencyProperty并且DependencyObject类的StringFormat属性Binding只是 a string。