Open file read-only

In a C# WinForms app, I am using System.IO.Diagnostics.Process.Start(fileName) to open files. The type of file can be .doc, .docx, .xls, .xlsx, .csv, .pdf, or .txt.

Is there any开发者_StackOverflow社区 way to force these files to be opened read-only?

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You need to set the file attributes of the file before you start the process and then set them back when you opened it.

Example:

var attributes = File.GetAttributes(path);

File.SetAttributes(filePath, attributes | FileAttributes.ReadOnly);

System.IO.Diagnostics.Process.Start(fileName);

File.SetAttributes(filePath, attributes);

Note: This will change the file attributes of the actual file, so keep that in mind.

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Unfortunately, the way of doing this changes with the type of file.

The best option is to check the ProcessStartInfo.Verbs property for a known verb for your file type. This is typically "OpenAsReadOnly". You'd then set that verb, and start the process with a ProcessStartInfo.

Just realize - this doesn't work for every type of file, since it's up to the program to supply and handle an appropriate verb.

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Can you copy the file to a temporary location, and then use the temp file to launch the program?

Then you could monitor the process and upon its exit, delete the temp file?

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Process.Start starts whatever program is associated with that file. You cannot instruct it to open the file as read-only, unless the program supports a command line argument to indicate that it should open as read-only (or if it supports the OpenAsReadOnly verb).

You could set file attributes on the file to read-only before opening it, but I don't think that is what you want.

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Depends on if the registered application has switch/option to support read-only mode. If so, you can pass in the read-only option. For your case, I don't think Process.Start can if no read-only option.