VS2015中通用Windows平台XAML设计器无法加载问题求助

Hey there, let's tackle this UI designer loading issue in VS2015 head-on. Since your app runs perfectly fine in debug mode but the designer refuses to load, here are some targeted fixes to try out:

• Clear the Visual Studio Designer Cache
  Corrupted cache files are a common culprit here. Navigate to these folders and delete all their contents:

  • %LOCALAPPDATA%\Microsoft\VisualStudio\14.0\Designer\ShadowCache
  • %LOCALAPPDATA%\Microsoft\VisualStudio\14.0\ComponentModelCache
    Restart VS2015 after cleaning these up—this often resolves minor designer glitches.

• Sync and Repair Project Designer Files
  The .designer.cs (or .designer.vb) files can get out of sync with your main form file over time:

  1. Right-click the problematic form in Solution Explorer → Unload Project.
  2. Right-click again → Edit [YourFormName].cs (or .vb).
  3. Scan the <Designer> section for malformed XML or missing entries. If you spot issues, compare it with a working form's designer file from a backup if you have one.
  4. Save the file, then right-click the project → Reload Project.

• Run a Full Visual Studio 2015 Repair
  Reinstalling the SDK didn't fix it, but a full VS repair can fix corrupted core components that the SDK install might miss:

  1. Open Control Panel → Programs and Features.
  2. Find Microsoft Visual Studio 2015 → right-click → Change.
  3. Select Repair and follow the prompts. It might take a while, but it’s great for fixing deep-seated installation issues.

• Check Third-Party Control Dependencies
  If your form uses custom third-party controls, the designer might fail to load if those controls aren’t properly registered or their versions don’t match:

  • Verify all referenced custom controls are installed correctly on your machine.
  • Make sure the version in your project’s references matches the installed version.
  • Try removing recently added custom controls temporarily to see if the designer loads—this helps isolate if a specific control is causing the problem.

• Toggle the Target .NET Framework Version
  Mismatches between your project’s target .NET version and VS2015’s configuration can break the designer:

  1. Right-click your project → Properties.
  2. Go to the Application tab.
  3. Switch to a compatible alternative version (e.g., if targeting 4.6, try 4.5.2), save changes, then switch back. This forces the project to refresh its framework references.

• Reset Visual Studio 2015 Settings
  Corrupted user settings can interfere with the designer’s functionality:

  1. Open VS2015 → go to Tools → Import and Export Settings.
  2. Select Reset all settings (you can back up your current settings first if you want) and follow the wizard.

If none of these work, try creating a blank project matching your type (Windows Forms/WPF) and gradually copy your form’s code and controls into it. This can help you pinpoint if the issue is tied to the original project file itself.

内容的提问来源于stack exchange，提问作者Rohit