4

I've WPF applcation in which I usedDataBinding for a comboBox. ProjectName from projectList should add inside my comboBox, but when I run the app, every time I get these errors;

System.Windows.Data Error: 40 : BindingExpression path error: 'projectList' property not found on 'object' ''DayView' (Name='MainWin')'. BindingExpression:Path=projectList; DataItem='DayView' (Name='MainWin'); target element is 'ComboBox' (Name=''); target property is 'ItemsSource' (type 'IEnumerable') System.Windows.Data Error: 40 : BindingExpression path error: 'selectedProjectid' property not found on 'object' ''ComboBox' (Name='')'. BindingExpression:Path=selectedProjectid; DataItem='ComboBox' (Name=''); target element is 'ComboBox' (Name=''); target property is 'SelectedValue' (type 'Object')

My xaml code where I use Data Binding is:

<DataTemplate x:Key="EditableDataTemplate">
            <StackPanel Orientation="Horizontal" Width="596">
                <TextBox Text="{Binding ClientNameBinding}" Background="Yellow" Padding="0" Margin="0" BorderThickness="0" TextWrapping="Wrap" Width="145"/>
                <TextBox Text="{Binding ApplicationNameBinding}" Background="Yellow" Padding="0" Margin="0" BorderThickness="0" TextWrapping="Wrap" Width="90"/>
                <TextBox Text="{Binding StartTimeBinding}" Background="Yellow" Padding="0" Margin="0" BorderThickness="0" TextWrapping="Wrap" Width="100"/>
                <TextBox Text="{Binding StopTimeBinding}" Background="Yellow" Padding="0" Margin="0" BorderThickness="0" TextWrapping="Wrap" Width="60"/>
                <TextBox Text="{Binding TaskNameBinding}" Background="Yellow" Padding="0" Margin="0" BorderThickness="0" TextWrapping="Wrap" Width="130"/>
                <ComboBox x:Name="ComboBox2" ItemsSource="{Binding Path=projectList, ElementName=MainWin}" SelectedValuePath="_id" DisplayMemberPath="_name" SelectedValue="{Binding Path=selectedProjectid}" Width="71" Background="Yellow" BorderThickness="0" DataContext="{Binding RelativeSource={RelativeSource Self}}"/>
            </StackPanel>
        </DataTemplate>

Code behind is:

public partial class DayView : MetroWindow
{
    private DateTime currentDateForWindow;

    public List<Harvest_Project> projectList;

    public int selectedProjectid{get;set;}

    public DayView(DateTime s)
    {
            InitializeComponent();
             this.DataContext = projectList;
            //this.RootElement.DataContext = myData;
            Globals._globalController.setDayViewWindow(this);

            currentDateForWindow = s;

            dayDateLabel.Content = s.DayOfWeek + ", " + s.Day;
            monthLabel.Content = s.ToString("MMMM");

            listBox1.Items.Clear();

            //projectList = Globals._globalController.harvestManager._PROJECTLIST;
            Globals._globalController.fetchAndPopulateForDate(currentDateForWindow);    
    }

    public void addHarvestEntrytoView(Harvest_TimeSheetEntry entry)
    {
        try
        {
            listBox1.Items.Add(entry);
        }
        catch (Exception)
        { }
    }

    public void addHarvestEntrytoView(List<Harvest_TimeSheetEntry> entry)
    {
        foreach (Harvest_TimeSheetEntry x in entry)
            listBox1.Items.Add(x);
    }

    private void BackButton_Click(object sender, RoutedEventArgs e)
    {
            this.Hide();
            Globals._globalController.getMonthViewWindow.Show();
    }

    private void StartButton_Click(object sender, RoutedEventArgs e)
    {
        Globals._globalController.win32Manager.startTimer();
    }

    private void StopButton_Click_1(object sender, RoutedEventArgs e)
    {
        Globals._globalController.win32Manager.stopTimer();

    }

    private void SyncEntry_Click(object sender, RoutedEventArgs e)
    {
        //Submit All unsynced Entries
    }

    private void ListBoxItem_MouseDoubleClick(object sender, RoutedEventArgs e)
    {
        //Submit clicked Entry
        Harvest_TimeSheetEntry entryToPost = (Harvest_TimeSheetEntry)sender;

        if (!entryToPost.isSynced)
        {
            //Check if something is selected in selectedProjectItem For that item


            if (entryToPost.ProjectNameBinding == "Select Project")
                MessageBox.Show("Please Select a Project for the Entry");
            else
                Globals._globalController.harvestManager.postHarvestEntry(entryToPost);
        }
        else
        {
            //Already synced.. Make a noise or something
            MessageBox.Show("Already Synced;TODO Play a Sound Instead");
        }
    }
}
4

3 回答 3

8

就像克里斯提到的那样，绑定只适用于公共领域。所以你至少要做：

 public List<Harvest_Project> projectList {get;set;}

您的 itemssource {Binding Path=projectList, ElementName=MainWin} 的 xaml 意味着您的元素 MainWin 有一个 Property projectList - 我认为这不是您想要的。

编辑：如果您有任何绑定错误，只需 2 个简单的步骤即可解决此问题

  1. 检查你的 DataContext
  2. 检查您的绑定路径

在运行时，您可以使用Snoop执行此任务。

对于您的 selectedProjectid 绑定：您需要一个具有公共属性 selectedProjectid 的 DataContext。如果不是这种情况，您应该检查您的代码

于 2013-06-24T12:29:24.560 回答
6

我想补充以上内容。我也有一个绑定错误。

    System.Windows.Data Error: BindingExpression path error: 'GeneralInformationTopicSectionItemStyles' property not found on 'GeneralInformation.Resources.LocalizationFiles' 'GeneralInformation.Resources.LocalizationFiles' (HashCode=7180698). BindingExpression: Path='GeneralInformationTopicSectionItemStyles.ItemNameTextWithoutSectionFontWeight' DataItem='GeneralInformation.Resources.LocalizationFiles' (HashCode=7180698); target element is 'System.Windows.Controls.TextBlock' (Name=''); target property is 'FontWeight' (type 'System.Windows.FontWeight')

我无法弄清楚问题是什么。在我的 LocalizationFiles 类中，我有成员。 

    public static object GeneralInformationTopicSectionItemStyles;

在阅读了上面的帖子后，我将其从成员更改为属性。

    public static object GeneralInformationTopicSectionItemStyles
    {
        get;
        set;
    }

瞧！它就像一个魅力。

毫米

于 2015-03-20T19:45:26.650 回答
2

这基本上是blindmeis已经说过的，但我会扩展我的评论=D

您的错误："BindingExpression path error: 'projectList' property not found on 'object' "是您的对象缺少属性定义的结果；在这种情况下projectList，当前不是属性（没有定义的访问器）。

您还应该有另一个公共财产来保存您选择的项目（或价值取决于您感兴趣的内容。

public partial class DayView : MetroWindow
{
    public List<Harvest_Project> projectList { get; set; }
    public Harvest_Project selectedProject  { get; set; }

    // Your other code lives here.
}

沿着这些线绑定（根据需要使用所有元素名称/上下文）：

<ComboBox x:Name="ComboBox2" 
     ItemsSource="{Binding Path=projectList}"
     SelectedItem="{Binding Path=selectedProject}" Mode=TwoWay}" />

如果您希望收到有关 selectedItem 更改的通知，则必须实施 iNotifyPropertyChanged，但这是另一个主题 =D

于 2013-06-24T13:16:48.897 回答