.NET中app.config与app.manifest的区别（WinForms项目场景）

Hey there! Let's break down the key differences between WinForms and other .NET project types (like WPF) when it comes to high-DPI settings targeting Windows 10 Creators Update, especially around those configuration files you're editing.

Core DPI Awareness Models #

• WinForms: Historically had limited high-DPI support, so you need to explicitly opt into modern DPI awareness for the Creators Update. The recommended mode here is Per-Monitor DPI Awareness v2, though System DPI Awareness is also an option. WinForms relies heavily on configuration files + code-level tweaks (like handling DpiChanged events) to get right.
• WPF/Modern .NET Projects: WPF has built-in DPI awareness by default (using System DPI Awareness out of the box). Enabling Per-Monitor v2 for Creators Update is more streamlined, and its vector-based layout engine means fewer scaling glitches without extra code fixes compared to WinForms.

Key Configuration File Differences #

Assuming you're working with the application manifest and app.config (the two most common files for DPI settings):

• Application Manifest:
  • For WinForms: You must add specific <dpiAware> and <dpiAwareness> elements to declare your DPI mode. For Creators Update's Per-Monitor v2, the entry looks like this:

    <application xmlns="urn:schemas-microsoft-com:asm.v3">
      <windowsSettings>
        <dpiAware xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">true/PM</dpiAware>
        <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2, PerMonitor</dpiAwareness>
      </windowsSettings>
    </application>
    

    Skip this, and WinForms will fall back to blurry legacy scaling on high-DPI displays.
  • For WPF: The manifest entry is similar, but WPF respects it natively. You won't need as many workarounds since its layout scales smoothly by default.
• app.config:
  • For WinForms: You need to add the System.Windows.Forms.ApplicationConfigurationSection (only applicable to WinForms) to enable .NET Framework 4.7+ high-DPI features required for Creators Update support:

    <configuration>
      <System.Windows.Forms.ApplicationConfigurationSection>
        <add key="DpiAwareness" value="PerMonitorV2" />
        <add key="EnableWindowsFormsHighDpiAutoResizing" value="true" />
      </System.Windows.Forms.ApplicationConfigurationSection>
    </configuration>
    

    This tells WinForms to use modern DPI APIs and auto-resize controls where possible.
  • For WPF: app.config doesn't require these WinForms-specific sections. WPF uses its own native DPI handling, with most adjustments done via the manifest or targeted code.

WinForms-Specific Notes for Your Project #

Since you're focused on a WinForms project:

• You must target .NET Framework 4.7 or higher to access the modern DPI APIs needed for Creators Update.
• Some legacy controls (like DataGridView) might still have scaling issues even with config settings—you may need to handle DpiChanged events manually to adjust sizes or fonts.
• Set AutoScaleMode.Dpi on your forms, and test each control's behavior across different DPI levels to catch edge cases.

Quick Recap #

The config changes you're making are specific to WinForms. The manifest settings are partially shared with other project types, but the app.config entries for System.Windows.Forms.ApplicationConfigurationSection are exclusive to WinForms projects. You don't need to worry about these affecting non-WinForms codebases.

内容的提问来源于stack exchange，提问作者Chris K