始终获取主监视器DPI

Question

我需要获取外接显示器的dpi，但是我总是可以获取主显示器的dpi。我也做了清单设置。我使用以下代码来获取它。

定义

public static void GetPerMonitorDPIEx(ref double dx, ref double dy, int x, 
      int y)
    {
        UInt32 dpiX = 0;
        UInt32 dpiY = 0;
        System.Drawing.Point pt = new System.Drawing.Point(x, y);
        bool m = SetProcessDpiAwarenessContext((int)PROCESS_DPI_AWARENESS.DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
        var mhandle = MonitorFromPoint( pt, Utils.DEFAULT_TO_NEAREST);
        uint m5 = GetDpiForMonitor(mhandle, MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI, out dpiX, out dpiY);
        dx = (double)dpiX / 96;
        dy = (double)dpiY / 96;
    }

通话

GetPerMonitorDPIEx(ref dpiX, ref dpiY, System.Windows.Forms.Screen.AllScreens[i].Bounds.Left + 1, System.Windows.Forms.Screen.AllScreens[i].Bounds.Top +1);

我可以看到两个屏幕的显示器手柄都正确，因为dpi值始终来自主显示器。

Answer 1

首先将您的应用程序设置为dpi感知，然后尝试检查输出

uint m5 = GetDpiForMonitor（mhandle，MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI，out dpiX，out dpiY）;