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我在使用 WPF 转换器时遇到问题，它给了我这个错误“无法设置多重绑定，因为必须指定多值转换器”。我查看了一些论坛并找到了一些信息，但它仍然显示错误

我的 .cs 代码：

namespace Scroll4
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>

        public partial class MainWindow : Window
        {
            public MainWindow()
            {
                //WindowState = WindowState.Maximized;
                InitializeComponent();
            }
            public class ScrollOffsetToVisibilityConverter : IMultiValueConverter
            {
                public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
                {
                    if (values == null)
                        throw new ArgumentException("Values cannot be null.");
                    if (values.Count() != 2)
                        throw new ArgumentException("Incorrect number of bindings (" + values.Count() + ")");
                    if (parameter == null)
                        throw new ArgumentException("Parameter cannot be null.");

                    var top = parameter.ToString().ToUpper() == "TOP";

                    var offset = Double.Parse(values[0].ToString());
                    var maxHeight = Double.Parse(values[1].ToString());

                    return (top && offset == 0) || (!top && offset == maxHeight) ? Visibility.Visible : Visibility.Collapsed;
                }

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

我的xml：

<Window x:Class="Scroll4.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
        xmlns:local="clr-namespace:Scroll4"
        Title="MainWindow" Height="350" Width="525">

        <Window.Resources>
                 <!--ERORR-->   
                 <local:ScrollOffsetToVisibilityConverter x:Key="Converter" />
                 <SolidColorBrush x:Key="Background" Color="Gray" />...

也许你知道如何解决它？

4

1 回答 1

1

似乎只是不正确的参考。转换器也有变化。数组具有 Count() 方法。可能你用过system.linq。只需使用您的命名空间更改 wpfApplication1

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;
namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            //WindowState = WindowState.Maximized;
            InitializeComponent();
        }
    }
    public class ScrollOffsetToVisibilityConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            if (values == null)
                throw new ArgumentException("Values cannot be null.");
            if (values.Length != 2)
                throw new ArgumentException("Incorrect number of bindings (" + values.Length + ")");
            if (parameter == null)
                throw new ArgumentException("Parameter cannot be null.");

            var top = parameter.ToString().ToUpper() == "TOP";

            var offset = Double.Parse(values[0].ToString());
            var maxHeight = Double.Parse(values[1].ToString());

            return (top && offset == 0) || (!top && offset == maxHeight) ? Visibility.Visible : Visibility.Collapsed;
        }

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

XAML 文件：

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525"
        xmlns:local="clr-namespace:WpfApplication1" >
    <Window.Resources>
        <local:ScrollOffsetToVisibilityConverter x:Name="ConverterName"  x:Key="Converter"/>
    </Window.Resources>
    <Grid>
        <TextBox Text="Hi"/>
    </Grid>
</Window>
于 2015-07-15T08:09:16.777 回答