我正在尝试使用C#编写一个Windows 8应用程序,在该应用程序中,我想通过FileOpenPicker显示用户选择的图像列表。我希望使用XAML数据绑定在GridView中显示这些图像。我已经尝试了一些方法,但是数据绑定似乎无法正常工作。我不确定在哪个位置需要设置GridView的itemssource。如果我在MainPage构造函数中这样做,那么当用户选择图像后,数据绑定的列表得到填充时,GridView不会刷新。如何解决这个问题?
更新 1
如果你想要绑定 GridView
,那么你需要添加几个东西。看一下我已经更新了我的回答并添加了一些注释行。你需要添加这些行来通过 XAML 提供 ItemsSource
。
给你。
C#
private async void btnBrowsePhotos_Click(object sender, RoutedEventArgs e)
{
//var objImageItem = new ImageItem();
FileOpenPicker openPicker = new FileOpenPicker();
openPicker.ViewMode = PickerViewMode.Thumbnail;
openPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
openPicker.FileTypeFilter.Add(".jpg");
openPicker.FileTypeFilter.Add(".jpeg");
openPicker.FileTypeFilter.Add(".png");
var files = await openPicker.PickMultipleFilesAsync();
List<ImageItem> ImageList = new List<ImageItem>();
foreach (var file in files)
{
using (var stream = await file.OpenAsync(FileAccessMode.Read))
{
//objImageItem.ImageList.Add(new ImageItem(stream, file.Name));
ImageList.Add(new ImageItem(stream, file.Name));
}
}
gv.ItemsSource = ImageList;
//gv.DataContext = objImageItem;
}
public class ImageItem //: INotifyPropertyChanged
{
/*private ObservableCollection<ImageItem> _ImageList = new ObservableCollection<ImageItem>();
public ObservableCollection<ImageItem> ImageList
{
get { return _ImageList; }
set { _ImageList = value; OnPropertyChanged("ImageList"); }
}*/
public BitmapImage Source { get; set; }
public string Name { get; set; }
public ImageItem()
{
}
public ImageItem(IRandomAccessStream stream, string name)
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(stream);
Source = bmp;
Name = name;
}
}
XAML
<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
<StackPanel>
<Button Click="btnBrowsePhotos_Click" Style="{StaticResource BrowsePhotosAppBarButtonStyle}" />
<!-- Add ItemsSource="{Binding ImageList}" to GridView -->
<GridView x:Name="gv">
<GridView.ItemTemplate>
<DataTemplate>
<Grid>
<Image Stretch="Fill" Source="{Binding Source}" Height="192" Width="342" />
<Border Opacity=".8" Background="Black" VerticalAlignment="Bottom" >
<TextBlock Text="{Binding Name}" FontSize="18"/>
</Border>
</Grid>
</DataTemplate>
</GridView.ItemTemplate>
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<WrapGrid MaximumRowsOrColumns="3" />
</ItemsPanelTemplate>
</GridView.ItemsPanel>
</GridView>
</StackPanel>
</Grid>
INotifyPropertyChanged
,否则可能无法工作。虽然你可以尝试并让我知道结果。 - Farhan Ghumra