将字段值传递给 Silverlight ConverterParameter [英] Pass value of a field to Silverlight ConverterParameter

问题描述

我正在编写我的第一个 Silverlight 应用程序.我有一个带有两个标签的列的数据网格，对于标签，我使用 IValueConverter 有条件地格式化数据.

I'm writing my very first Silverlight app. I have a datagrid with a column that has two labels, for the labels, i am using an IValueConverter to conditionally format the data.

标签的内容"设置如下:

The label's "Content" is set as such:

Content="{Binding HomeScore, Converter={StaticResource fmtshs}}"

和

Content="{Binding AwayScore, Converter={StaticResource fmtshs}}"

我的 IValueConverter 的 Convert 方法是这样的:

The Convert method of my IValueConverter is such:

Public Function Convert(
  ByVal value As Object, 
  ByVal targetType As System.Type, 
  ByVal parameter As Object, 
  ByVal culture As System.Globalization.CultureInfo) As Object 
Implements System.Windows.Data.IValueConverter.Convert

    Dim score As Long = value, other As Long = parameter

    Return If(score < 0, "", 
        If(score - other > 5, (other + 5).ToString, score.ToString)
    )

End Function

所以我想要做的是在 HomeScore 的转换器中，我想将 AwayScore 传递给 ConverterParameter，而对于 AwayScore，我想将 HomeScore 传递给转换器.在任一分数的转换器中，我需要能够知道另一个分数的值以进行格式化.

So what i want to do is in the converter for HomeScore, i want to pass AwayScore to the ConverterParameter, and for AwayScore i want to pass the HomeScore to the converter. In the converter for either score i need to be able to know the value of the other score for formatting purposes.

但我无法弄清楚将 ConverterParameter 绑定到另一个字段的语法.
我尝试了以下方法:

But i cannot figure out the syntax for binding the ConverterParameter to another field.
I've tried the following:

Content="{Binding HomeScore, Converter={StaticResource fmtshs}, ConverterParameter=AwayScore}"  
Content="{Binding HomeScore, Converter={StaticResource fmtshs}, ConverterParameter={AwayScore}}"  
Content="{Binding HomeScore, Converter={StaticResource fmtshs}, ConverterParameter={Binding AwayScore}}"  

但这些似乎都不起作用.如何将字段值传递给 ConverterParameter?

But none of those seem to work. How do i pass a field value to the ConverterParameter?

推荐答案

因为除了文字之外，你不能将任何东西传递到 ConverterParameter 中，所以解决方案是将整个对象传递到转换器中，然后您可以从转换器中访问它的所有属性.

As you can't pass anything but a literal into the ConverterParameter the solution is to pass the whole object into the converter and then you can access all of it's properties from within the Converter.

所以你的代码变成了(假设你的对象叫做Match):

So your code becomes (assuming your object is called Match):

Public Function Convert(
  ByVal value As Object, 
  ByVal targetType As System.Type, 
  ByVal parameter As Object, 
  ByVal culture As System.Globalization.CultureInfo) As Object 
Implements System.Windows.Data.IValueConverter.Convert

    Dim match As Match = value

    ' Do stuff with match'

End Function

(对于代码中缺乏细节表示歉意)

(Apologies for lack of detail in the code)

那么你的 XAML 就变成了

Then your XAML becomes

Content="{Binding Converter={StaticResource fmtshs}}"

注意 虽然您显然是直接绑定到转换器，但实际上并非如此.您绑定到数据上下文而不指定 Path，因此您可以访问整个内容.

NOTE While you are apparently binding directly to the converter, that's not actually the case. You are binding to the data context without specifying a Path so you can use access the whole thing.

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