需要一个这样的过程:
服务器指定目录中存在一些图片。
站点程序读取图片存入数据库并删除源图片。
代码如下:
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可在这个函数执行中,发现有很严重的问题,图片源文件无法删除。
提示错误如下:
文件“E:\SUNBOY\\temp\bd8df21a-5ff9-4dd8-aff8-6feb5d2b1f85\test.jpg”正由另一进程使用,因此该进程无法访问该文件。
乍一看,这段代码应该是没问题的,怎么会出这样的错误呢?(我保证文件在进入这段代码前是不会被使用的)
通过把 File.Delete(ImageFilePath); 放在
//读取图片文件
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只前,之后的比较发现,罪魁祸首是System.Drawing.Image.FromFile(ImageFilePath);
很显然,System.Drawing.Image.FromFile 函数在读取图片后,并没有关闭掉文件。
跟平时编程的常识好象有些出入。
例如:photo.ImageLength = new FileInfo(ImageFilePath).Length;
经过测试发现,使用FileInfo 类获得文件的大小后,文件就被关闭了。
很奇怪,不知道这里是bug 呢,还是刻意的。
没办法,只好自己考虑了解决方法:
读取文件流,使用System.Drawing.Image.FromStream 方法。
这样就可以自己操作文件,自己进行关闭了。
经过测试,这样是可行的,不过不知道效率如何!
代码如下:
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