如何在查看文件时复用Visual Studio实例？WPF应用打开.feature文件异常

Hey there, let's tackle this issue you're facing with your WPF app opening .feature files in VS 2015 instead of 2017. Here are a few solid solutions depending on what you need:

1. Update System Default File Association (Simplest Approach) #

The most straightforward fix is to set VS 2017 as the default app for .feature files system-wide:

• Right-click any .feature file on your machine
• Select Open with > Choose another app
• Check the box that says "Always use this app to open .feature files"
• Browse to your VS 2017 executable (typical path: C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.exe — adjust "Community" to "Professional" or "Enterprise" if you have that version)
• Confirm your selection, and moving forward Process.Start(path) will use VS 2017 by default

2. Force VS 2017 Opening in Code (Bypass System Associations) #

If you don't want to mess with system defaults, or need guaranteed control over which VS version opens the file, modify your code to directly call VS 2017's executable:

// Update this path to match your VS 2017 installation
var vs2017ExePath = @"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.exe";
var featureFileFullPath = "YourFullFeatureFilePath.feature";

// Launch VS 2017 with the target file
Process.Start(new ProcessStartInfo(vs2017ExePath, $"\"{featureFileFullPath}\""));

• Note: Double-check the path to devenv.exe — if you're on a 64-bit system and installed VS to the 64-bit directory, it might be under C:\Program Files instead of C:\Program Files (x86).
• This method ensures your app always uses VS 2017, regardless of system-level file associations.

3. Reset File Association Cache via Command Line #

Sometimes Windows caches file association settings, which can cause unexpected behavior. Here's how to reset it manually:

1. Open Command Prompt as Administrator
2. Run assoc .feature to check the registered file type (e.g., it might return .feature=SpecFlowFeatureFile)
3. Run ftype SpecFlowFeatureFile to see the current associated program path — if it points to VS 2015, update it with:

   ftype SpecFlowFeatureFile="C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.exe" "%1"
   

4. Restart your WPF app and test again

If you noticed inconsistent behavior when repeating the feature, this cache reset should help stabilize things. If the issue persists, the code-based approach (solution 2) is your safest bet.

内容的提问来源于stack exchange，提问作者C Robinson