使用包打开 XPS 文件会保持文件锁定

Question

以下 C# 代码保持文件锁定，因此 DeleteFile 失败：

String srcFile = @"D:\I\deleteme\TempFiles\Mem\XPS\1.xps";

Package package = Package.Open(srcFile, FileMode.Open, FileAccess.Read, FileShare.Read);

XpsDocument xpsDoc = new XpsDocument(package, CompressionOption.Normal, srcFile);

/* Calling this is what actually keeps the file open.
   Commenting out the call to GetFixedDocumentSequence() does not cause lock */
FixedDocumentSequence fds = xpsDoc.GetFixedDocumentSequence();

xpsDoc.Close();
package.Close();

File.Delete(srcFile); /* This will throw an exception because the file is locked */

非常相似的代码，从文件而不是包打开 XpsDocument 不会保持文件锁定：

String srcFile = @"D:\I\deleteme\TempFiles\Mem\XPS\1.xps";

XpsDocument xpsDoc = new XpsDocument(srcFile, FileAccess.Read, CompressionOption.Normal);

/* If XpsDocument is opened from file instead of package,
   GetFixedDocumentSequence() doesn't keep the file open */
FixedDocumentSequence fds = xpsDoc.GetFixedDocumentSequence();

xpsDoc.Close();

File.Delete(srcFile); /* This will throw an exception because the file is locked */

我看到另一个帖子说如果你从文件中打开文档，你需要手动关闭底层包，但对我来说似乎不是这样。

我在这里放了一个项目和示例文件：https://drive.google.com/open?id=1GTCaxmcQUDpAoPHpsu_sC3_rK3p6Zv5z

Answer 1

您没有正确处理包裹。将其包装在 using 中很可能会解决问题：

String srcFile = @"D:\I\deleteme\TempFiles\Mem\XPS\1.xps";

using(Package package = Package.Open(srcFile, FileMode.Open, FileAccess.Read, FileShare.Read))
{

    XpsDocument xpsDoc = new XpsDocument(package, CompressionOption.Normal, srcFile);

    /* Calling this is what actually keeps the file open.
       Commenting out the call to GetFixedDocumentSequence() does not cause lock 
    */
    FixedDocumentSequence fds = xpsDoc.GetFixedDocumentSequence();

    xpsDoc.Close();
    package.Close();
}

File.Delete(srcFile);

如果这不能解决问题，您可以考虑添加额外的 FileShare 值（特别是 FileShare.Delete），但这只会隐藏根本问题而不是解决它。