在 Windows 10 移动版中读取图像时出错

Posted 2023-02-19

【中文标题】在 Windows 10 移动版中读取图像时出错

【英文标题】：Error reading a image in Windows 10 Mobile

【发布时间】：2016-08-08 19:02:23

【问题描述】：

我在选择图像后遇到了一个简单的图像库问题，我将它发送到 Windows 10 中的另一个屏幕，它运行良好，但是当我在手机中尝试时，它会无缘无故地崩溃，我的代码如下一：

XAML 代码：

<Page
    x:Class="Stop_Diabetes.Pages.Camera"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Stop_Diabetes.Pages"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="#227EC2" Loaded="Page_Loaded">
    
    <Page.Resources>
        <local:ImageConverter x:Key="imageConverter"/>
        <DataTemplate x:Key="imageTemplate">
            <Grid Width="190" Height="130">
                <Image Source="Binding Path=Thumbnail, 
            Converter=StaticResource imageConverter" Tapped="Image_Tapped"
            Width="200" Height="200"/>
            </Grid>
        </DataTemplate>
        <CollectionViewSource 
        x:Name="picturesSource"/>
    </Page.Resources>
    
    <Grid>
        <Grid x:Name="stkGallery" Canvas.ZIndex="15" VerticalAlignment="Bottom">
            <GridView x:Name="gvPictures" VerticalAlignment="Top" Height="150"  ItemsSource="Binding Source=StaticResource picturesSource" ItemTemplate="StaticResource imageTemplate"  ScrollViewer.HorizontalScrollMode="Enabled" ScrollViewer.HorizontalScrollBarVisibility="Visible">
                <GridView.ItemsPanel>
                    <ItemsPanelTemplate>
                        <WrapGrid Orientation="Vertical"></WrapGrid>
                    </ItemsPanelTemplate>
                </GridView.ItemsPanel>
            </GridView>
        </Grid>
    </Grid>
</Page>

C#重要代码：

private void Page_Loaded(object sender, RoutedEventArgs e)

    List<string> fileTypeFilter = new List<string>();
    fileTypeFilter.Add(".jpg");
    fileTypeFilter.Add(".jpeg");
    fileTypeFilter.Add(".png");
    fileTypeFilter.Add(".gif");
    fileTypeFilter.Add(".bmp");
    //Define thr query to iterate thriugh all the subfolders 
    var pictureQueryOptions = new QueryOptions(CommonFileQuery.OrderByDate, fileTypeFilter);
    //Read through all the subfolders. 
    pictureQueryOptions.FolderDepth = FolderDepth.Deep;
    //Apply the query on the PicturesLibrary 
    var pictureQuery = KnownFolders.PicturesLibrary.CreateFileQueryWithOptions(pictureQueryOptions);
    // 
    var picturesInformation = new FileInformationFactory(pictureQuery, ThumbnailMode.PicturesView);
    picturesSource.Source = picturesInformation.GetVirtualizedFilesVector();


private async void Image_Tapped(object sender, Windows.UI.Xaml.Input.TappedRoutedEventArgs e)

    Image img = (Image)sender;
    FileInformation fi = img.DataContext as FileInformation;
    if (fi != null)
    
        string path = fi.Name;
        //do something with the path...

        var pStorage = KnownFolders.PicturesLibrary;

        StorageFile file = await pStorage.GetFileAsync(path);

        ImageProperties imgProp = await file.Properties.GetImagePropertiesAsync();

        using (var imgStream = await file.OpenAsync(FileAccessMode.Read))
        
            WriteableBitmap bitmap = new WriteableBitmap((int)imgProp.Width, (int)imgProp.Height);
            bitmap.SetSource(imgStream);

            Frame.Navigate(typeof(Crop), bitmap);
        
    


public class ImageConverter : IValueConverter

    public object Convert(object value, Type targetType, object parameter, string culture)
    
        if (value != null)
        
            var img = (IRandomAccessStream)value;
            var picture = new BitmapImage();
            picture.SetSource(img);
            return picture;
        
        return DependencyProperty.UnsetValue;
    
    public object ConvertBack(object value, Type targetType, object parameter, string culture)
    
        throw new NotImplementedException();
    

我的问题发生在这里：

StorageFile 文件 = 等待 pStorage.GetFileAsync(path);

PC 可以完美打开图像，但是当我打电话时它显示：

Message = "系统找不到指定的文件。\r\n"

这很奇怪，因为图像已加载但稍后无法打开，我尝试了不同的选项，如 ID、路径等，但没有一个有效。有谁知道我应该在 Windows 10 移动版中进行哪些更改？

这或多或少应该是当前代码的结果：

【参考方案1】：

fileinfo 类有一个 openAsync 和 OpenReadAsync 方法，为什么不使用它们呢？

https://msdn.microsoft.com/en-us/library/windows/apps/br207562

https://msdn.microsoft.com/en-us/library/windows/apps/windows.storage.bulkaccess.fileinformation.openreadasync

这是您应该更改的代码

 using (var imgStream = await fi.OpenReadAsync())

【讨论】：

我已经在这里使用它了： using (var imgStream = await file.OpenAsync(FileAccessMode.Read)) WriteableBitmap bitmap = new WriteableBitmap((int)imgProp.Width, (int)imgProp.高度）; bitmap.SetSource(imgStream); Frame.Navigate(typeof(Crop), bitmap); 但您仍然需要指定您尝试打开的文件。