c# - 从 ListView 显示所选图像的新窗口无权访问图像路径

Question

我有一个带有 ListView 的应用程序，我通过单击添加图像按钮将图像添加到该列表中，我还有一个用于从该列表中删除图像的按钮。我为此使用 SelectedImage 对象，一切正常。但我想要一个按钮来显示选定的图像，这就是我这样做的方式：

        private ObservableCollection<Image> imageList = new ObservableCollection<Image>();
        private Image selectedImage = new Image();

        public MainViewModel()
        {
            AddImagesCommand = new RelayCommand(AddImagesMethod);
            RemoveImagesCommand = new RelayCommand(RemoveImagesMethod);
            ShowImageCommand = new RelayCommand(ShowImageMethod);
            SelectedImageCommand = new RelayCommand(SelectedImageMethod);
        }

        public ICommand AddImagesCommand { get; set; }
        public ICommand ShowImageCommand { get; set; }
        public ICommand RemoveImagesCommand { get; set; }
        public ICommand SelectedImageCommand { get; set; }

        public ObservableCollection<Image> ImageList
        {
            get
            {
                return imageList;
            }
        }

          public Image SelectedImage
        {
            get
            {
                return selectedImage;
            }
            set
            {
                selectedImage = value;
            }
        }

        public void SelectedImageMethod()
        {
            Image selected = SelectedImage;
            RaisePropertyChanged("SelectedImage");
        }


        public void AddImagesMethod()
        {
            ...
            blablabla
            ....
            imageList.Add(new Image
            {
                Name = _name,
                SafeName = safeImageName,
                Weight = sLen,
                CheckboxDefault = false
            }) ;
            this.RaisePropertyChanged(() => this.ImageList);
        }


        public void RemoveImagesMethod()
        {
            imageList.Remove(SelectedImage);
            RaisePropertyChanged("RemoveImagesCommand");
        }

        public void ShowImageMethod()
        {
            //string V = @"pack://application:,,,/inred;component/Sources/test.jpg";
            //string V = @"pack://application:,,,/inred;component/Sources/" + SelectedImage.SafeName;
            ImageWindow win2 = new ImageWindow(SelectedImage.Name);
            win2.Show();
            RaisePropertyChanged("ShowImageCommand");
        }

问题是 SelectedImage.Name 和 SelectedImage.SafeName 是空的，我不明白为什么相同的 SelectedImage 用于 RemoveImageCommand 并且工作正常。带有 test.jpg 的字符串 V 有效，但第二个 V 无效。请给我一些指示，我缺少什么。

更新： 这是 MainWindow 的 XAML：

    <Grid DataContext="{Binding MainViewModel, Source={StaticResource Locator}}" >
        <ListView x:Name="Images" HorizontalAlignment="Left" Height="100" Margin="20,148,0,0" VerticalAlignment="Top" Width="581" ItemsSource="{Binding ImageList}" SelectedItem="{Binding SelectedImage}">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="Name" Width="120" DisplayMemberBinding="{Binding SafeName}" />
                    <GridViewColumn Header="Description" Width="120">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <TextBox HorizontalAlignment="Left" Height="23" VerticalAlignment="Top" Width="200" Text="{Binding Description}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn Header="Weight" Width="75" DisplayMemberBinding="{Binding Weight}" />
                    <GridViewColumn Header = "Actions" Width = "150">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <StackPanel Orientation="Horizontal">
                                    <Grid>
                                        <Button Content="Show" 
                                CommandParameter="{Binding}"
                                Command="{Binding DataContext.ShowImageCommand, 
                                            RelativeSource={RelativeSource FindAncestor, 
                                            AncestorType={x:Type local:MainWindow}}}" />
                                    </Grid>
                                    <Grid>
                                        <Button Content="Annotate" 
                                CommandParameter="{Binding}"
                                Command="{Binding DataContext.AnnotateImageCommand, 
                                            RelativeSource={RelativeSource FindAncestor, 
                                            AncestorType={x:Type local:MainWindow}}}" />
                                    </Grid>
                                </StackPanel>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn Header = "Default" Width = "50">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <RadioButton GroupName="allFiles" IsChecked="{Binding CheckboxDefault}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                </GridView>
            </ListView.View>
        </ListView>
        <Button Content="Add Image" HorizontalAlignment="Left" Margin="645,148,0,0" VerticalAlignment="Top" Width="75" RenderTransformOrigin="-0.282,-0.25" Command="{Binding AddImagesCommand}"/>
        <Button Content="Remove Image" HorizontalAlignment="Left" Margin="645,226,0,0" VerticalAlignment="Top" Width="75" RenderTransformOrigin="-0.282,-0.25" Command="{Binding RemoveImagesCommand}"/>
    </Grid>

这是ImageWindow：

    public partial class ImageWindow : Window
    {
        public ImageWindow(string imagePath)
        {
            InitializeComponent();
            BitmapImage bitmap = new BitmapImage();
            bitmap.BeginInit();
            bitmap.UriSource = new Uri(imagePath);
            bitmap.EndInit();
            ImageViewer1.Source = bitmap;
        }
    }

标签： c#wpfimagelistviewmvvm

Answer 1

您确定单击按钮时选择了一个项目吗？此外，由于您将 绑定CommandParameter到 中的当前Image，ListView您应该在命令中使用此参数：

ShowImageCommand = new RelayCommand<Image>(ShowImageMethod);
...
public void ShowImageMethod(Image image)
{
    ImageWindow win2 = new ImageWindow(image.Name);
    win2.Show();
}