如何在 WPF 中获取 DPI？
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53798 次
10 回答
81
https://docs.microsoft.com/en-us/archive/blogs/jaimer/getting-system-dpi-in-wpf-app似乎工作
PresentationSource source = PresentationSource.FromVisual(this);
double dpiX, dpiY;
if (source != null) {
dpiX = 96.0 * source.CompositionTarget.TransformToDevice.M11;
dpiY = 96.0 * source.CompositionTarget.TransformToDevice.M22;
}
于 2009-12-17T01:17:46.300 回答
52
var dpiXProperty = typeof(SystemParameters).GetProperty("DpiX", BindingFlags.NonPublic | BindingFlags.Static);
var dpiYProperty = typeof(SystemParameters).GetProperty("Dpi", BindingFlags.NonPublic | BindingFlags.Static);
var dpiX = (int)dpiXProperty.GetValue(null, null);
var dpiY = (int)dpiYProperty.GetValue(null, null);
于 2012-09-19T02:53:04.290 回答
37
使用 .NET 4.6.2 Preview 及更高版本，您可以调用VisualTreeHelper.GetDpi(Visual visual). 它返回一个DpiScale结构，该结构告诉您Visual将呈现或已经呈现给定的 DPI。
于 2016-05-11T18:06:35.757 回答
7
我发现获得“真实”显示器 dpi 的唯一方法如下。所有其他提到的技术都只是说 96，这对于大多数显示器来说是不正确的。
public class ScreenInformations
{
public static uint RawDpi { get; private set; }
static ScreenInformations()
{
uint dpiX;
uint dpiY;
GetDpi(DpiType.RAW, out dpiX, out dpiY);
RawDpi = dpiX;
}
/// <summary>
/// Returns the scaling of the given screen.
/// </summary>
/// <param name="dpiType">The type of dpi that should be given back..</param>
/// <param name="dpiX">Gives the horizontal scaling back (in dpi).</param>
/// <param name="dpiY">Gives the vertical scaling back (in dpi).</param>
private static void GetDpi(DpiType dpiType, out uint dpiX, out uint dpiY)
{
var point = new System.Drawing.Point(1, 1);
var hmonitor = MonitorFromPoint(point, _MONITOR_DEFAULTTONEAREST);
switch (GetDpiForMonitor(hmonitor, dpiType, out dpiX, out dpiY).ToInt32())
{
case _S_OK: return;
case _E_INVALIDARG:
throw new ArgumentException("Unknown error. See https://msdn.microsoft.com/en-us/library/windows/desktop/dn280510.aspx for more information.");
default:
throw new COMException("Unknown error. See https://msdn.microsoft.com/en-us/library/windows/desktop/dn280510.aspx for more information.");
}
}
//https://msdn.microsoft.com/en-us/library/windows/desktop/dd145062.aspx
[DllImport("User32.dll")]
private static extern IntPtr MonitorFromPoint([In]System.Drawing.Point pt, [In]uint dwFlags);
//https://msdn.microsoft.com/en-us/library/windows/desktop/dn280510.aspx
[DllImport("Shcore.dll")]
private static extern IntPtr GetDpiForMonitor([In]IntPtr hmonitor, [In]DpiType dpiType, [Out]out uint dpiX, [Out]out uint dpiY);
const int _S_OK = 0;
const int _MONITOR_DEFAULTTONEAREST = 2;
const int _E_INVALIDARG = -2147024809;
}
/// <summary>
/// Represents the different types of scaling.
/// </summary>
/// <seealso cref="https://msdn.microsoft.com/en-us/library/windows/desktop/dn280511.aspx"/>
public enum DpiType
{
EFFECTIVE = 0,
ANGULAR = 1,
RAW = 2,
}
于 2015-04-08T13:35:00.613 回答
7
我已经从 2015 年更新了我的答案。这是一些实用程序代码，它使用 Windows 10 中的最新 DPI 函数（特别是GetDpiForWindow 函数，它是唯一支持窗口/应用程序/进程等的 DPI_AWARENESS 的方法）但回退到较旧的（每台显示器的 dpi 和桌面 dpi），因此它仍应适用于 Windows 7。
它不依赖于 WPF 或 Winforms，仅依赖于 Windows 本身。
// note this class considers dpix = dpiy
public static class DpiUtilities
{
// you should always use this one and it will fallback if necessary
// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getdpiforwindow
public static int GetDpiForWindow(IntPtr hwnd)
{
var h = LoadLibrary("user32.dll");
var ptr = GetProcAddress(h, "GetDpiForWindow"); // Windows 10 1607
if (ptr == IntPtr.Zero)
return GetDpiForNearestMonitor(hwnd);
return Marshal.GetDelegateForFunctionPointer<GetDpiForWindowFn>(ptr)(hwnd);
}
public static int GetDpiForNearestMonitor(IntPtr hwnd) => GetDpiForMonitor(GetNearestMonitorFromWindow(hwnd));
public static int GetDpiForNearestMonitor(int x, int y) => GetDpiForMonitor(GetNearestMonitorFromPoint(x, y));
public static int GetDpiForMonitor(IntPtr monitor, MonitorDpiType type = MonitorDpiType.Effective)
{
var h = LoadLibrary("shcore.dll");
var ptr = GetProcAddress(h, "GetDpiForMonitor"); // Windows 8.1
if (ptr == IntPtr.Zero)
return GetDpiForDesktop();
int hr = Marshal.GetDelegateForFunctionPointer<GetDpiForMonitorFn>(ptr)(monitor, type, out int x, out int y);
if (hr < 0)
return GetDpiForDesktop();
return x;
}
public static int GetDpiForDesktop()
{
int hr = D2D1CreateFactory(D2D1_FACTORY_TYPE.D2D1_FACTORY_TYPE_SINGLE_THREADED, typeof(ID2D1Factory).GUID, IntPtr.Zero, out ID2D1Factory factory);
if (hr < 0)
return 96; // we really hit the ground, don't know what to do next!
factory.GetDesktopDpi(out float x, out float y); // Windows 7
Marshal.ReleaseComObject(factory);
return (int)x;
}
public static IntPtr GetDesktopMonitor() => GetNearestMonitorFromWindow(GetDesktopWindow());
public static IntPtr GetShellMonitor() => GetNearestMonitorFromWindow(GetShellWindow());
public static IntPtr GetNearestMonitorFromWindow(IntPtr hwnd) => MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
public static IntPtr GetNearestMonitorFromPoint(int x, int y) => MonitorFromPoint(new POINT { x = x, y = y }, MONITOR_DEFAULTTONEAREST);
private delegate int GetDpiForWindowFn(IntPtr hwnd);
private delegate int GetDpiForMonitorFn(IntPtr hmonitor, MonitorDpiType dpiType, out int dpiX, out int dpiY);
private const int MONITOR_DEFAULTTONEAREST = 2;
[DllImport("kernel32", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr LoadLibrary(string lpLibFileName);
[DllImport("kernel32", CharSet = CharSet.Ansi, SetLastError = true)]
private static extern IntPtr GetProcAddress(IntPtr hModule, string lpProcName);
[DllImport("user32")]
private static extern IntPtr MonitorFromPoint(POINT pt, int flags);
[DllImport("user32")]
private static extern IntPtr MonitorFromWindow(IntPtr hwnd, int flags);
[DllImport("user32")]
private static extern IntPtr GetDesktopWindow();
[DllImport("user32")]
private static extern IntPtr GetShellWindow();
[StructLayout(LayoutKind.Sequential)]
private partial struct POINT
{
public int x;
public int y;
}
[DllImport("d2d1")]
private static extern int D2D1CreateFactory(D2D1_FACTORY_TYPE factoryType, [MarshalAs(UnmanagedType.LPStruct)] Guid riid, IntPtr pFactoryOptions, out ID2D1Factory ppIFactory);
private enum D2D1_FACTORY_TYPE
{
D2D1_FACTORY_TYPE_SINGLE_THREADED = 0,
D2D1_FACTORY_TYPE_MULTI_THREADED = 1,
}
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("06152247-6f50-465a-9245-118bfd3b6007")]
private interface ID2D1Factory
{
int ReloadSystemMetrics();
[PreserveSig]
void GetDesktopDpi(out float dpiX, out float dpiY);
// the rest is not implemented as we don't need it
}
}
public enum MonitorDpiType
{
Effective = 0,
Angular = 1,
Raw = 2,
}
于 2015-10-01T12:52:26.010 回答
4
这就是我设法在 WPF 中获得“比例因子”的方式。我的笔记本电脑的分辨率是 1920x1440。
int resHeight = System.Windows.Forms.Screen.PrimaryScreen.Bounds.Height; // 1440
int actualHeight = SystemParameters.PrimaryScreenHeight; // 960
double ratio = actualHeight / resHeight;
double dpi = resHeigh / actualHeight; // 1.5 which is true because my settings says my scale is 150%
于 2019-02-28T19:03:20.610 回答
3
使用GetDeviceCaps功能：
static void Main(string[] args)
{
// 1.25 = 125%
var dpi = GetDpi();
}
[DllImport("user32.dll")]
public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);
[DllImport("user32.dll")]
public static extern IntPtr GetDC(IntPtr hwnd);
[DllImport("gdi32.dll")]
static extern int GetDeviceCaps(IntPtr hdc, int nIndex);
private static float GetDpi()
{
IntPtr desktopWnd = IntPtr.Zero;
IntPtr dc = GetDC(desktopWnd);
var dpi = 100f;
const int LOGPIXELSX = 88;
try
{
dpi = GetDeviceCaps(dc, LOGPIXELSX);
}
finally
{
ReleaseDC(desktopWnd, dc);
}
return dpi / 96f;
}
于 2018-09-14T11:58:17.317 回答
1
您可以尝试使用 ManagementClass：
public static string GetDPI()
{
using (ManagementClass mc = new ManagementClass("Win32_DesktopMonitor"))
{
using (ManagementObjectCollection moc = mc.GetInstances())
{
int PixelsPerXLogicalInch = 0; // dpi for x
int PixelsPerYLogicalInch = 0; // dpi for y
foreach (ManagementObject each in moc)
{
PixelsPerXLogicalInch = int.Parse((each.Properties["PixelsPerXLogicalInch"].Value.ToString()));
PixelsPerYLogicalInch = int.Parse((each.Properties["PixelsPerYLogicalInch"].Value.ToString()));
}
return PixelsPerXLogicalInch + "," + PixelsPerYLogicalInch;
}
}
}
于 2021-01-25T14:12:34.623 回答
0
2017 年 1 月 25 日下午 3:54
“从桌面应用程序调用 Windows 10 API”和
https://docs.microsoft.com/en-us/uwp/api/windows.devices.display.displaymonitor
“显示监控类”
命名空间：Windows.Devices.Display 程序集：Windows.Devices.Display.dll、Windows.dll
提供有关连接到系统的显示监视器设备的信息。
这些数据包括来自显示器的扩展显示标识数据（EDID，这是一个行业标准的显示描述符块，几乎所有显示器都使用它来提供支持的模式和一般设备信息的描述）和 DisplayID（这是一个较新的行业标准）中的常用信息提供了 EDID 的超集）。
RawDpiX
获取显示器的物理水平 DPI（基于显示器的原始分辨率和物理尺寸）。
RawDpiY
获取显示器的物理垂直 DPI（基于显示器的原始分辨率和物理尺寸）。
于 2018-09-21T10:04:43.887 回答
0
2006 年以来 Windows 中的基本监视器信息
https://docs.microsoft.com/en-us/windows/desktop/wmicoreprov/msmonitorclass
MSMonitorClass 类
WmiMonitorRawEEdidV1Block 类
WmiMonitorBasicDisplayParams 类
MaxHorizontalImageSize ( EDID byte 21 )
MaxVerticalImageSize ( EDID byte 22 )
（ EDID 中的大小以厘米为单位，在 EDID 详细时序描述符中以毫米为单位
12 水平图像大小，mm，8 lsbits（0–4095 mm，161 in）
13 垂直图像大小，mm，8 lsbits（0–4095 mm，161 in）
14 位 7–4 水平图像大小，mm，4 msbits
位3–0 垂直图像大小，mm，4 msbits
)
和
于 2018-09-22T05:38:02.353 回答