组合框IsEnabled绑定问题在Silverlight XAML中 [英] ComboBox IsEnabled Binding Question in Silverlight Xaml

问题描述

我有一个组合框的XAML如下：

I have a ComboBox whose xaml is as follows

<ComboBox Name="ComboBoxDiscussionType" IsEnabled="{Binding ElementName=ComboBoxDiscussionType, Path=Items.Count, Converter={StaticResource ComboBoxItemsCountToBoolConverter}}"/>

和转换器取Items.Count并检查其是否大于0，如果该值大于0，则启用其他禁用

and the converter takes the Items.Count and checks if its greater than 0 if its greater than 0 then enable it else disable it

我们的目标是使组合框如果ComboBox仅当它有它其他的项目禁用它，
（个体经营绑定到其item.count）

The goal is enable the ComboBox if the ComboBox only if it has Items in it else disable it, ( self Binding to its item.count )

下面是我的转换器，

public class ComboBoxItemsCountToBoolConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return (int)value > 0;
    }
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return null;
    }
}

我如何实现的呢？现在上面绑定给我一个错误

how do i achieve it? right now the above Binding gives me an error

推荐答案

有关，我不明白，在Silverlight中的值由转换器所看到是原因键入双击，但它应该是 INT 。事实上，它是一个 INT WPF的。

For reasons that I don't understand, on Silverlight the value as seen by the converter is of type double but it should be int. In fact it is an int on WPF.

不过既然是这样的话，就处理它的为 双击解决了这一问题：

But since this is the case, just processing it as a double fixed the problem:

public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
    return (int)(double)value > 0;
}

奇怪的是，一个更传统的相对源绑定不工作之一：

Strangely enough, a more traditional relative source binding doesn't work either:

<Binding RelativeSource="{RelativeSource Self}" .../>

但你的原始元素名称绑定的作用：

but your original element name binding does:

<ComboBox Name="ComboBoxDiscussionType" IsEnabled="{Binding ElementName=ComboBoxDiscussionType, Path=Items.Count, Converter={StaticResource ComboBoxItemsCountToBoolConverter}}"/>

这似乎是pretty车给我，但Silverlight是一个奇怪的野兽的时候。

This seems pretty buggy to me, but Silverlight is a strange beast sometimes.

这篇关于组合框IsEnabled绑定问题在Silverlight XAML中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！