屏幕AllScreens问题 [英] Screen AllScreens problem

问题描述

您好，我遇到了这个问题，我有一些应该在Windows服务中工作的代码来计算连接在PC上的屏幕数量，我使用Screen.AllScreens来获取屏幕数量，无论如何，它如果我从控制台应用程序调用代码就可以正常工作，但是当我在winservice中使用相同的代码时，Screen.AllScreens中的监视器数量始终为1，无法连接两个监视器。

Do你知道这里发生了什么吗？

Hello, I am having this problem, I have some code that should be working in a windows service to count the number of screens connected in the pc, I am using Screen.AllScreens to get the number of screens, anyway, it works just fine if I call the code from a console app, but when I use the same code in the winservice the monitor count in Screen.AllScreens is always 1, nerveless there are two monitors connected.
Do you have any idea what is going on here?

推荐答案

尝试使用 pinvoke [ ^ ]常规框架方法失败的地方，



以下是使用 http://g4ac.co.za/zp3Dz中的代码的示例 [ ^ ]

try using pinvoke[^] where the regular framework methods fail you,

eample of this is below using the code from http://g4ac.co.za/zp3Dz[^]

[DllImport("user32.dll")]
        static extern bool EnumDisplayMonitors(IntPtr hdc, IntPtr lprcClip,
           MonitorEnumDelegate lpfnEnum, IntPtr dwData);
        delegate bool MonitorEnumDelegate(IntPtr hMonitor, IntPtr hdcMonitor, ref Rect lprcMonitor, IntPtr dwData);
        [StructLayout(LayoutKind.Sequential)]
        public struct Rect
        {
            public int left;
            public int top;
            public int right;
            public int bottom;
        }
        /// <summary>
        /// The struct that contains the display information
        /// </summary>
        public class DisplayInfo
        {
            public string Availability { get; set; }
            public string ScreenHeight { get; set; }
            public string ScreenWidth { get; set; }
            public Rect MonitorArea { get; set; }
            public Rect WorkArea { get; set; }
        }
        /// <summary>
        /// Collection of display information
        /// </summary>
        public class DisplayInfoCollection : List<DisplayInfo>
        {
        }
        [DllImport("user32.dll")]
        static extern bool GetMonitorInfo(IntPtr hMonitor, ref MonitorInfoEx lpmi);
        [DllImport("user32.dll")]
        static extern bool GetMonitorInfo(IntPtr hMonitor, ref MonitorInfo lpmi);
        // size of a device name string
        private const int CCHDEVICENAME = 32;
        /// <summary>
        /// The MONITORINFOEX structure contains information about a display monitor.
        /// The GetMonitorInfo function stores information into a MONITORINFOEX structure or a MONITORINFO structure.
        /// The MONITORINFOEX structure is a superset of the MONITORINFO structure. The MONITORINFOEX structure adds a string member to contain a name
        /// for the display monitor.
        /// </summary>
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        internal struct MonitorInfoEx
        {
            /// <summary>
            /// The size, in bytes, of the structure. Set this member to sizeof(MONITORINFOEX) (72) before calling the GetMonitorInfo function.
            /// Doing so lets the function determine the type of structure you are passing to it.
            /// </summary>
            public int Size;
            /// <summary>
            /// A RECT structure that specifies the display monitor rectangle, expressed in virtual-screen coordinates.
            /// Note that if the monitor is not the primary display monitor, some of the rectangle's coordinates may be negative values.
            /// </summary>
            public Rect Monitor;
            /// <summary>
            /// A RECT structure that specifies the work area rectangle of the display monitor that can be used by applications,
            /// expressed in virtual-screen coordinates. Windows uses this rectangle to maximize an application on the monitor.
            /// The rest of the area in rcMonitor contains system windows such as the task bar and side bars.
            /// Note that if the monitor is not the primary display monitor, some of the rectangle's coordinates may be negative values.
            /// </summary>
            public Rect WorkArea;
            /// <summary>
            /// The attributes of the display monitor.
            ///
            /// This member can be the following value:
            ///   1 : MONITORINFOF_PRIMARY
            /// </summary>
            public uint Flags;
            /// <summary>
            /// A string that specifies the device name of the monitor being used. Most applications have no use for a display monitor name,
            /// and so can save some bytes by using a MONITORINFO structure.
            /// </summary>
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCHDEVICENAME)]
            public string DeviceName;
            public void Init()
            {
                this.Size = 72;
                this.DeviceName = string.Empty;
            }
        }
        [StructLayout(LayoutKind.Sequential)]
        internal struct MonitorInfo
        {
            /// <summary>
            /// The size, in bytes, of the structure. Set this member to sizeof(MONITORINFO) (40) before calling the GetMonitorInfo function.
            /// Doing so lets the function determine the type of structure you are passing to it.
            /// </summary>
            public int Size;
            /// <summary>
            /// A RECT structure that specifies the display monitor rectangle, expressed in virtual-screen coordinates.
            /// Note that if the monitor is not the primary display monitor, some of the rectangle's coordinates may be negative values.
            /// </summary>
            public Rect Monitor;
            /// <summary>
            /// A RECT structure that specifies the work area rectangle of the display monitor that can be used by applications,
            /// expressed in virtual-screen coordinates. Windows uses this rectangle to maximize an application on the monitor.
            /// The rest of the area in rcMonitor contains system windows such as the task bar and side bars.
            /// Note that if the monitor is not the primary display monitor, some of the rectangle's coordinates may be negative values.
            /// </summary>
            public Rect WorkArea;
            /// <summary>
            /// The attributes of the display monitor.
            ///
            /// This member can be the following value:
            ///   1 : MONITORINFOF_PRIMARY
            /// </summary>
            public uint Flags;
            public void Init()
            {
                this.Size = 40;
            }
        }
        /// <summary>
        /// Returns the number of Displays using the Win32 functions
        /// </summary>
        /// <returns>collection of Display Info</returns>
        public DisplayInfoCollection GetDisplays()
        {
            DisplayInfoCollection col = new DisplayInfoCollection();
            EnumDisplayMonitors(IntPtr.Zero, IntPtr.Zero,
                delegate(IntPtr hMonitor, IntPtr hdcMonitor, ref Rect lprcMonitor, IntPtr dwData)
                {
                    MonitorInfo mi = new MonitorInfo();
                    mi.Size = (int)Marshal.SizeOf(mi);
                    bool success = GetMonitorInfo(hMonitor, ref mi);
                    if (success)
                    {
                        DisplayInfo di = new DisplayInfo();
                        di.ScreenWidth = (mi.Monitor.right - mi.Monitor.left).ToString();
                        di.ScreenHeight = (mi.Monitor.bottom - mi.Monitor.top).ToString();
                        di.MonitorArea = mi.Monitor;
                        di.WorkArea = mi.WorkArea;
                        di.Availability = mi.Flags.ToString();
                        col.Add(di);
                    }
                    return true;
                }, IntPtr.Zero);
            return col;
        }
        public int GetTotalMonitors()
        {
            return GetDisplays().Count;
        }

获取总数的方法是GetTotalMonitors（）

Your method to Get the total is GetTotalMonitors()

string mesEnabledMoni = "";
int EnabledMoniId= 1;
foreach (Screen screen in Screen.AllScreens)
{
	string str = String.Format("Monitor {0}: {1} x {2} @ {3},{4}\n", EnabledMoniId , screen.Bounds.Width,
		screen.Bounds.Height, screen.Bounds.X, screen.Bounds.Y);
	mesEnabledMoni += str;
	EnabledMoniId ++;
}

MessageBox.Show(mesEnabledMoni, "EnumDisp");

System.Windows .Forms.Screen类获取有关所有已启用监视器的信息

System.Windows.Forms.Screen class to get information about all enabled monitor

这篇关于屏幕AllScreens问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！