如果存在则提供静态文件，否​​则创建它

Question

如何使StaticFile处理程序仅提供实际存在的文件，并使其他人转到asp.net mvc管道或自定义http处理程序。

1) GET /images/file.jpg
  exists => serve it (StaticFile handler / as efficiently as possible)

2) GET /images/file_640x480.jpg
  1. request (doesn't exist)
  * load file.jpg
  * resize
  * save as file_640x480.jpg
  => serve from memory

  following requests 
  => should use 1) because the file is now there

<modules runAllManagedModulesForAllRequests="true" />这是微不足道的 但我想这更像是一种解决方法，而不是一种真正的解决方案。

Answer 1

我没有尝试过这段代码，但这些代码上的内容应该可以正常工作

public FilePathResult GetFile(string name)
{
    FileInfo info = new FileInfo(name);
    if (!info.Exists)
    {
        //Code to load the original file, resize and save would go here
    }

    return File(name, "text/plain");
}