Question

我有以下要求：

显示项目的TreeView
在TreeView。
用于编辑所选项目的对话框。

我已经实现了这些要求，但是第三个要求没有按预期执行，所以我被卡住了。

我想要它做什么：编辑对话框应该能够编辑项目。这不是TreeViewItem，而是我的一个类的实例。

保存编辑 - 一个只关闭对话框的按钮。
放弃编辑 - 用于重置项目和关闭对话框中更改的字段的按钮。

第二项要求不起作用。如果我编辑字段并点击取消，则项目详细信息面板仍会显示编辑内容。我已经调试但是我发现基础项目没有改变 - 但是项目显示的是更改的值。

代码：

项目类别（类别）

public class Category
{
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
    public virtual string Description { get; set; }
    public virtual Unit Unit { get; set; }
    public virtual List<Category> ChildCategories { get; set; }
    public virtual Category ParentCategory { get; set; }
    public virtual bool IsMainCategory { get; set; }

    public Category()
    {
        ChildCategories = new List<Category>();
    }

    public virtual void AddChild(Category child)
    {
        ChildCategories.Add(child);
        child.ParentCategory = this;
    }
}

项目（类别）详细信息显示在标签中：

<DataTemplate DataType="{x:Type local:Category}">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="4*" SharedSizeGroup="a" />
            <ColumnDefinition Width="6*" SharedSizeGroup="b" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="1*" />
            <RowDefinition Height="1*" />
        </Grid.RowDefinitions>

        <TextBlock Text="Name" Grid.Column="0" Grid.Row="0" Padding="5"/>
        <TextBlock Text="{Binding Path=Name}" Grid.Column="1" Grid.Row="0" Padding="5"/>
        <TextBlock Text="Description" Grid.Column="0" Grid.Row="1" Padding="5"/>
        <TextBlock Text="{Binding Path=Description}" Grid.Column="1" Grid.Row="1" Padding="5"/>
    </Grid>
</DataTemplate>

主窗口中编辑项目的事件处理程序：

private void EditCategory(object sender, RoutedEventArgs e)
{
    Category ctg = _tree.SelectedItem as Category;
    if (ctg != null)
    {
        CategoryDefineWindow cdw = new CategoryDefineWindow();
        cdw.CategoryObject = ctg;
        cdw.ShowDialog();
    }
}

项目编辑器窗口xaml：

<Window x:Class="BSRCat.View.CategoryDefineWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Height="150" Width="500">
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="3*" SharedSizeGroup="a" />
        <ColumnDefinition Width="7*" SharedSizeGroup="b" />
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="1*" />
        <RowDefinition Height="1*" />
        <RowDefinition Height="1*" />
    </Grid.RowDefinitions>

    <TextBlock Text="Name" Grid.Column="0" Grid.Row="0" Padding="5"/>
    <TextBox Text="{Binding Path=CategoryObject.Name, RelativeSource={RelativeSource AncestorType=Window}}" Grid.Column="1" Grid.Row="0" Padding="5"/>
    <TextBlock Text="Description" Grid.Column="0" Grid.Row="1" Padding="5"/>
    <TextBox Text="{Binding Path=CategoryObject.Description, RelativeSource={RelativeSource AncestorType=Window}}" Grid.Column="1" Grid.Row="1" Padding="5"/>

    <StackPanel Orientation="Horizontal" Grid.Row="2" Grid.ColumnSpan="2" HorizontalAlignment="Right">
        <Button Content="Ok" Margin="5" Height="20" Width="30" Click="Confirmed"/>
        <Button Content="Cancel" Margin="5" Height="20" Width="50" Click="Cancelled"/>
    </StackPanel>
</Grid>
</Window>

项目编辑器窗口代码背后：

public partial class CategoryDefineWindow : Window
{
    public Category CategoryObject 
    {
        get
        {
        return _category;
        }
        set
        {
            _category = value;
            _initial = new Category() { Name = value.Name, Description = value.Description     };
        }
    }

    private Category _category;
    private Category _initial;

    public CategoryDefineWindow()
    {
        InitializeComponent();
    }

    private void Confirmed(object sender, RoutedEventArgs e)
    {
        Close();
    }

    private void Cancelled(object sender, RoutedEventArgs e)
    {
        _category.Name = _initial.Name;
        _category.Description = _initial.Description;
        Close();
    }
}

我调试了CategoryDefineWindow.Cancelled方法，并且正确重置了_category对象。我找不到它出错的地方。

Answer 1

类别类应该实现INotifyPropertyChanged接口。一旦属性值发生变化，WPF将会收到通知。

   public class Category : INotifyPropertyChanged
{
    private string _Name;
    private string _Description;

    public virtual int Id { get; set; }
    public virtual string Name
    {
        get
        {
            return _Name;
        }
        set
        {
            if (_Name == value)
                return;

            _Name = value;
            NotifyPropertyChanged("Name");
        }
    }

    public virtual string Description
    {
        get
        {
            return _Description;
        }
        set
        {
            if (_Description == value)
                return;

            _Description = value;
            NotifyPropertyChanged("Description");
        }
    }
    public virtual Unit Unit { get; set; }
    public virtual List<Category> ChildCategories { get; set; }
    public virtual Category ParentCategory { get; set; }
    public virtual bool IsMainCategory { get; set; }

    public Category()
    {
        ChildCategories = new List<Category>();
    }

    public virtual void AddChild(Category child)
    {
        ChildCategories.Add(child);
        child.ParentCategory = this;
    }

    private void NotifyPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
}

父窗口中的数据更改反映错误

1 个答案: