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嗨,我是 WPF C# 的新手,我正在将 winform 应用程序转换为 WPF,我在数据绑定方面遇到了困难(我对绑定没有好主意)。我收到错误消息:

绑定表达式路径错误:在 'object' ' ' String' 上找不到 Classes 属性 HashCode = "" 目标元素是 'TextBlock'(Name =' '); 目标属性是文本(类型“字符串”)

请帮忙。谢谢

我正在使用 XML 文件并存储一个包含类(字符串值列表,如旋转、拖动)、坐标点列表和输出值的序列。这是我的数据库类。

public class Database
    {
     public BindingList<string> Classes { get;  set; }
        public BindingList<Sequence> Samples { get;  set; }


        public Database()
        {
            Classes = new BindingList<string>();
            Samples = new BindingList<Sequence>();
        }

        public void Save(Stream stream)
        {
            var serializer = new XmlSerializer(typeof(BindingList<Sequence>));
            serializer.Serialize(stream, Samples);
        }


        public void Load(Stream stream)
        {
            var serializer = new XmlSerializer(typeof(BindingList<Sequence>));
            var samples = (BindingList<Sequence>)serializer.Deserialize(stream);

            Classes.Clear();
            foreach (string label in samples.First().Classes)
            {
                Classes.Add(label);
                Console.WriteLine(" lets check out the classes ....." + label);
            }

            Samples.Clear();
            foreach (Sequence sample in samples)
            {
                sample.Classes = Classes;
                Samples.Add(sample);
                Console.WriteLine(" lets check out the samples ....." + sample);
            }
        }
}
}

序列是这样的----------------

Sequence sample = new Sequence()
            {
                Classes = Classes,
                SourcePath = sequence,
                Output = classIndex
            };

现在我有一个组合框,它从 BindingList 类和数据网格中获取值,从序列中获取值。XML 文件是

<Window x:Class="WpfLearnGUI.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="417" Width="608">

    <DockPanel Width="Auto" Height="Auto" LastChildFill="True">

        <DataGrid 
            DataContext="{Binding}" ItemsSource="{Binding }"
            AutoGenerateColumns="false" Height="73" 
            Name="gridSamples"  Width="Auto"  HorizontalAlignment="Right"  DockPanel.Dock="Right"  VerticalAlignment="Top" IsEnabled="True">

        <DataGrid.Columns>
            <DataGridTextColumn 
                  Header="Gesture" />
            <DataGridTextColumn 
                    Header="Class" 
                   />
        </DataGrid.Columns>
      </DataGrid>

        <Grid Height="Auto" Name="grid1" Background="Coral" DockPanel.Dock="Bottom" Width="Auto" >
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="240*"/>
                <ColumnDefinition Width="264*" />

            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="*" />
                <RowDefinition Height="*"/>
                 <RowDefinition Height="*"/>
            </Grid.RowDefinitions>

            <ComboBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="105,0,0,0" Name="cbClasses" VerticalAlignment="Top" Width="120"  DisplayMemberPath="Classes" SelectedValuePath="Classes" IsEditable="True" DataContext="{Binding}" ItemsSource="{Binding}" />

            <Button Content="DataBase" Grid.Column="2" Grid.Row="2" Height="23" HorizontalAlignment="Left" Margin="53,1,0,0" 
                    Name="button5" VerticalAlignment="Top" Width="75" >
                <Button.ContextMenu>
                    <ContextMenu>
                        <Menu>
                            <MenuItem Header="_Open" IsCheckable="True" Click="Open_click"></MenuItem>
                        </Menu>
                    </ContextMenu>  
                </Button.ContextMenu>
                </Button>
        </Grid> 
    </DockPanel>
</Window>

我像这样在 mainWindow 中绑定这两个值。

database = new Database();
cbClasses.ItemsSource = database.Classes;
gridSamples.DataContext = database.Samples;            
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1 回答 1

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我认为您可能需要退后一步,阅读一些关于 WPF 绑定的教程,特别是以下概念: * 实现 INotifyPropertyChanged * MVVM 模式

我建议你看看这个链接,它提供了一个非常好的概述(带有可下载的源代码)。您还可以查看我对另一个问题的回答,该问题演示了一些非常基本的数据绑定技术。

于 2013-03-14T10:49:10.407 回答