Question

我正在处理这段代码：在内部方法调用中，元数据属性都被填充; 但在用户代码中，大多数都是无效的。为什么会出现这种情况？

public static BitmapFrame GetImageIPTC(string imageFile)
{
    BitmapFrame meta;
    using (var fs = new FileStream(imageFile, FileMode.Open))
    {
        BitmapDecoder decoder = new JpegBitmapDecoder(fs, BitmapCreateOptions.None, BitmapCacheOption.None);
        meta = decoder.Frames[0];
        var a = ((BitmapMetadata) meta.Metadata).CameraModel;

    }
    return meta;

}

在方法内部，元数据属性为：

        ApplicationName "Adobe Photoshop CS5 Windows"   string
-       Author  Count = 1   System.Collections.ObjectModel.ReadOnlyCollection<string>
        [0] "Michele Virgilio"  string
        CameraManufacturer  "Canon" string
        CameraModel "Canon EOS 450D"    string
        Comment null    string
        Copyright   "© Michele Virgilio"    string
        DateTaken   "16/04/2011 10:30:48"   string
        Format  "jpg"   string
        IsFixedSize false   bool
        IsReadOnly  false   bool
+       Keywords    Count = 96  System.Collections.ObjectModel.ReadOnlyCollection<string>
        Location    "/" string
        Rating  0   int
        Subject "Subject description"   string
        Title   "Title description" string

用户代码：

var actual = ImageInfo.GetImageIPTC(filespec);
var bitmapMetadata = (BitmapMetadata)actual.Metadata;
var a = bitmapMetadata.CameraModel;

正如你所看到的那样，除了主题：

之外的所有属性

        ApplicationName "Adobe Photoshop CS5 Windows"   string
-       Author  Count = 1   System.Collections.ObjectModel.ReadOnlyCollection<string>
        [0] "Michele Virgilio"  string
        CameraManufacturer  "Canon" string
        CameraModel "Canon EOS 450D"    string
        Comment null    string
        Copyright   "© Michele Virgilio"    string
        DateTaken   "16/04/2011 10:30:48"   string
        Format  "jpg"   string
        IsFixedSize false   bool
        IsReadOnly  true    bool
+       Keywords    Count = 96  System.Collections.ObjectModel.ReadOnlyCollection<string>
        Location    "/" string
        Rating  0   int
        Subject null    string
        Title   "Title description" string

Answer 1

当离开使用范围时，将处理BitmapDecoder。检查return meta行调试器中的元数据，您将看到。

BitmapMetadata：一些属性清除？

1 个答案: