add ColorDropper

src/Shared/HandyControl_Shared/Controls/ColorPicker/ColorDropper.cs

@@ -1,9 +1,69 @@
-using System.Windows.Controls;
+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using System.Windows.Media;
+using HandyControl.Data;
+using HandyControl.Tools;
+using HandyControl.Tools.Interop;
 
 namespace HandyControl.Controls
 {
-    public class ColorDropper : Control
+    internal class ColorDropper : Control
     {
-        
+        private Cursor _dropperCursor;
+
+        private readonly ColorPicker _colorPicker;
+
+        public ColorDropper(ColorPicker colorPicker)
+        {
+            _colorPicker = colorPicker;
+        }
+
+        public void Update(bool isShow)
+        {
+            if (isShow)
+            {
+                if (_dropperCursor == null)
+                {
+                    var info = Application.GetResourceStream(
+                        new Uri("pack://application:,,,/HandyControl;Component/Resources/dropper.cur"));
+                    if (info != null)
+                    {
+                        _dropperCursor = new Cursor(info.Stream);
+                    }
+                }
+
+                if (_dropperCursor == null) return;
+
+                Mouse.OverrideCursor = _dropperCursor;
+                MouseHook.Start();
+                MouseHook.StatusChanged += MouseHook_StatusChanged;
+            }
+            else
+            {
+                Mouse.OverrideCursor = Cursors.Arrow;
+            }
+        }
+
+        private void MouseHook_StatusChanged(object sender, MouseHookEventArgs e)
+        {
+            if (!_colorPicker.IsMouseOver && e.Message == MouseHookMessageType.LeftButtonDown)
+            {
+                var brush = new SolidColorBrush(GetColorAt(e.Point.X, e.Point.Y));
+                _colorPicker.SelectedBrush = brush;
+                //MouseHook.Stop();
+                //MouseHook.StatusChanged -= MouseHook_StatusChanged;
+            }
+        }
+
+        public static Color GetColorAt(int x, int y)
+        {
+            var desk = UnsafeNativeMethods.GetDesktopWindow();
+            var dc = UnsafeNativeMethods.GetWindowDC(desk);
+            var a = (int)UnsafeNativeMethods.GetPixel(dc, x, y);
+            UnsafeNativeMethods.ReleaseDC(desk, dc);
+            return Color.FromArgb(255, (byte) ((a >> 0) & 0xff), (byte) ((a >> 8) & 0xff), (byte) ((a >> 16) & 0xff));
+        }
     }
 }

src/Shared/HandyControl_Shared/Controls/ColorPicker/ColorPicker.cs

@@ -41,7 +41,7 @@ namespace HandyControl.Controls
 
         #region Data
 
-        private Cursor _dropperCursor;
+        private ColorDropper _colorDropper;
 
         private ToggleButton _toggleButtonDropper;
 
@@ -696,25 +696,12 @@ namespace HandyControl.Controls
 
         private void ToggleButtonDropper_Click(object sender, RoutedEventArgs e)
         {
-            if (_toggleButtonDropper.IsChecked == true)
+            if (_colorDropper == null)
             {
-                if (_dropperCursor == null)
-                {
-                    var info = Application.GetResourceStream(new Uri("pack://application:,,,/HandyControl;Component/Resources/dropper.cur"));
-                    if (info != null)
-                    {
-                        _dropperCursor = new Cursor(info.Stream);
-                    }
-                }
-
-                if (_dropperCursor == null) return;
-
-                Mouse.OverrideCursor = _dropperCursor;
-            }
-            else
-            {
-                Mouse.OverrideCursor = Cursors.Arrow;
+                _colorDropper = new ColorDropper(this);
             }
+            // ReSharper disable once PossibleInvalidOperationException
+            _colorDropper.Update(_toggleButtonDropper.IsChecked.Value);
         }
 
         public void Dispose() => System.Windows.Window.GetWindow(this)?.Close();

src/Shared/HandyControl_Shared/Data/Args/MouseHookEventArgs.cs

@@ -0,0 +1,12 @@
+using System;
+using HandyControl.Tools.Interop;
+
+namespace HandyControl.Data
+{
+    internal class MouseHookEventArgs : EventArgs
+    {
+        public MouseHookMessageType Message { get; set; }
+
+        public NativeMethods.POINT Point { get; set; }
+    }
+}

src/Shared/HandyControl_Shared/Data/Enum/MouseHookMessageType.cs

@@ -0,0 +1,12 @@
+namespace HandyControl.Data
+{
+    public enum MouseHookMessageType
+    {
+        LeftButtonDown = 0x0201,
+        LeftButtonUp = 0x0202,
+        MouseMove = 0x0200,
+        MouseWheel = 0x020A,
+        RightButtonDown = 0x0204,
+        RightButtonUp = 0x0205
+    }
+}

src/Shared/HandyControl_Shared/HandyControl_Shared.projitems

@@ -113,6 +113,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Controls\Window\Window.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\Args\CancelRoutedEventArgs.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\Args\FunctionEventArgs!1.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Data\Args\MouseHookEventArgs.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\ColorRange.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\Enum\BadgeStatus.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\Enum\ChatMessageType.cs" />
@@ -136,6 +137,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Data\GrowlInfo.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\HandyControlConfig.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\MessageBoxInfo.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Data\Enum\MouseHookMessageType.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\Operation\OperationResult!1.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\Operation\OperationResult.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Data\ResourceToken.cs" />
@@ -244,6 +246,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\SingleOpenHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\ValidateHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\VisualHelper.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Tools\Hook\MouseHook.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Interop\BitmapHandle.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Interop\BITMAPINFO.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Interop\CommonHandles.cs" />

src/Shared/HandyControl_Shared/Tools/Hook/MouseHook.cs

@@ -1,7 +1,48 @@
-namespace HandyControl.Tools
-{
-    public class MouseHook
-    {
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using HandyControl.Data;
+using HandyControl.Tools.Interop;
 
+namespace HandyControl.Tools
+{
+    internal class MouseHook
+    {
+        public static event EventHandler<MouseHookEventArgs> StatusChanged;
+
+        private static IntPtr HookId = IntPtr.Zero;
+
+        private static readonly UnsafeNativeMethods.HookProc Proc = HookCallback;
+
+        public static void Start() => HookId = SetHook(Proc);
+
+        public static void Stop() => UnsafeNativeMethods.UnhookWindowsHookEx(HookId);
+
+        private static IntPtr SetHook(UnsafeNativeMethods.HookProc proc)
+        {
+            using (var curProcess = Process.GetCurrentProcess())
+            using (var curModule = curProcess.MainModule)
+            {
+                if (curModule != null)
+                {
+                    return UnsafeNativeMethods.SetWindowsHookEx((int) UnsafeNativeMethods.HookType.WH_MOUSE_LL, proc,
+                        UnsafeNativeMethods.GetModuleHandle(curModule.ModuleName), 0);
+                }
+                return IntPtr.Zero;
+            }
+        }
+
+        private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
+        {
+            if (nCode < 0) return UnsafeNativeMethods.CallNextHookEx(HookId, nCode, wParam, lParam);
+            var hookStruct = (UnsafeNativeMethods.MOUSEHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(UnsafeNativeMethods.MOUSEHOOKSTRUCT));
+            StatusChanged?.Invoke(null, new MouseHookEventArgs
+            {
+                Message = (MouseHookMessageType)wParam,
+                Point = new NativeMethods.POINT(hookStruct.pt.X, hookStruct.pt.Y)
+            });
+
+            return UnsafeNativeMethods.CallNextHookEx(HookId, nCode, wParam, lParam);
+        }
     }
 }

src/Shared/HandyControl_Shared/Tools/Interop/UnsafeNativeMethods.cs

@@ -174,5 +174,45 @@ namespace HandyControl.Tools.Interop
 
         [DllImport(ExternDll.User32, ExactSpelling = true, CharSet = CharSet.Auto)]
         public static extern bool SetForegroundWindow(IntPtr hWnd);
+
+        [DllImport(ExternDll.User32, CharSet = CharSet.Auto, SetLastError = true)]
+        public static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);
+
+        [DllImport(ExternDll.Kernel32, CharSet = CharSet.Auto, SetLastError = true)]
+        public static extern IntPtr GetModuleHandle(string lpModuleName);
+
+        [DllImport(ExternDll.User32, CharSet = CharSet.Auto, SetLastError = true)]
+        public static extern bool UnhookWindowsHookEx(IntPtr hhk);
+
+        public enum HookType
+        {
+            WH_MOUSE_LL = 14,
+        }
+
+        [StructLayout(LayoutKind.Sequential)]
+        public struct MOUSEHOOKSTRUCT
+        {
+            public NativeMethods.POINT pt;
+            public IntPtr hwnd;
+            public uint wHitTestCode;
+            public IntPtr dwExtraInfo;
+        }
+
+        public delegate IntPtr HookProc(int code, IntPtr wParam, IntPtr lParam);
+
+        [DllImport(ExternDll.User32, CharSet = CharSet.Auto, SetLastError = true)]
+        public static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, uint dwThreadId);
+
+        [DllImport(ExternDll.User32, SetLastError = true)]
+        public static extern IntPtr GetDesktopWindow();
+
+        [DllImport(ExternDll.User32, SetLastError = true)]
+        public static extern IntPtr GetWindowDC(IntPtr window);
+
+        [DllImport(ExternDll.Gdi32, SetLastError = true)]
+        public static extern uint GetPixel(IntPtr dc, int x, int y);
+
+        [DllImport(ExternDll.User32, SetLastError = true)]
+        public static extern int ReleaseDC(IntPtr window, IntPtr dc);
     }
 }