二重起動時に既存のプロセスがアクティブにならない不具合を修正

ウィンドウが表示されていない状態ではProcess.MainWindowHandleが正しいハンドルを返さないため、ウィンドウハンドルの検索とアクティブ化をWin32 APIで実装した。

diff --git a/OpenTween/ApplicationEvents.cs b/OpenTween/ApplicationEvents.cs
index 21bae9b..67ffc51 100644 (file)
--- a/OpenTween/ApplicationEvents.cs
+++ b/OpenTween/ApplicationEvents.cs
@@ -139,19 +139,15 @@ namespace OpenTween
         {
             // 実行中の同じアプリケーションのウィンドウ・ハンドルの取得
             var prevProcess = GetPreviousProcess();
-            if (prevProcess == null || prevProcess.MainWindowHandle == IntPtr.Zero)
+            if (prevProcess == null)
             {
                 return;
             }
 
-            var form = Control.FromHandle(prevProcess.MainWindowHandle) as Form;
-            if (form != null)
+            IntPtr windowHandle = NativeMethods.GetWindowHandle((uint)prevProcess.Id, Application.ProductName);
+            if (windowHandle != IntPtr.Zero)
             {
-                if (form.WindowState == FormWindowState.Minimized)
-                {
-                    NativeMethods.RestoreWindow(form);
-                }
-                form.Activate();
+                NativeMethods.SetActiveWindow(windowHandle);
             }
         }
 

diff --git a/OpenTween/NativeMethods.cs b/OpenTween/NativeMethods.cs
index 2f339ce..bb35c60 100644 (file)
--- a/OpenTween/NativeMethods.cs
+++ b/OpenTween/NativeMethods.cs
@@ -33,6 +33,7 @@ using System.Net;
 using System.Runtime.InteropServices;
 using System.Threading;
 using System.Windows.Forms;
+using System.Text;
 using OpenTween.Connection;
 
 namespace OpenTween
@@ -469,5 +470,95 @@ namespace OpenTween
 
             return si.nPos;
         }
+
+        #region "ウィンドウの検索"
+
+        [DllImport("user32.dll")]
+        private static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint procId);
+        
+        private delegate int EnumWindowCallback(IntPtr hWnd, int lParam);
+
+        [DllImport("user32")]
+        private static extern int EnumWindows(EnumWindowCallback lpEnumFunc, int lParam);
+
+        [DllImport("user32.dll", CharSet = CharSet.Auto)]
+        private static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
+
+        [DllImport("user32.dll", CharSet = CharSet.Auto)]
+        private static extern int GetWindowTextLength(IntPtr hWnd);
+
+        private static uint targetPid;
+        private static IntPtr targetHwnd;
+        private static string targetWindowTitle;
+
+        private static int CheckPidAndTitle(IntPtr hWnd, int lParam)
+        {
+            uint procId;
+            uint threadId = GetWindowThreadProcessId(hWnd, out procId);
+
+            if (procId == targetPid)
+            {
+                int windowTitleLen = GetWindowTextLength(hWnd);
+
+                if (windowTitleLen > 0)
+                {
+                    StringBuilder windowTitle = new StringBuilder(windowTitleLen + 1);
+                    GetWindowText(hWnd, windowTitle, windowTitle.Capacity);
+
+                    if (windowTitle.ToString().IndexOf(targetWindowTitle) >= 0)
+                    {
+                        targetHwnd = hWnd;
+                        return 0;
+                    }
+                }
+            }
+
+            return 1;
+        }
+
+        /// <summary>
+        /// 指定したPIDとタイトルを持つウィンドウのウィンドウハンドルを取得します
+        /// </summary>
+        /// <param name="pid">対象ウィンドウのPID</param>
+        /// <param name="windowTitle">対象ウィンドウのタイトル</param>
+        /// <returns>ウィンドウハンドル。検索に失敗した場合は0</returns>
+        public static IntPtr GetWindowHandle(uint pid, string windowTitle)
+        {
+            targetPid = pid;
+            targetWindowTitle = windowTitle;
+            targetHwnd = IntPtr.Zero;
+
+            EnumWindows(new EnumWindowCallback(CheckPidAndTitle), 0);
+            return targetHwnd;
+        }
+
+        #endregion
+
+        #region "ウィンドウのアクティブ化"
+
+        private enum ShowWindowCommands : int
+        {
+            SW_SHOW = 5 // ウィンドウを現在の位置とサイズにする
+        }
+
+        [DllImport("user32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool ShowWindow(IntPtr hWnd, ShowWindowCommands nCmdShow);
+
+        [DllImport("user32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool SetForegroundWindow(IntPtr hWnd);
+
+        /// <summary>
+        /// 指定したウィンドウをアクティブにします
+        /// </summary>
+        /// <param name="hWnd">アクティブにするウィンドウのウィンドウハンドル</param>
+        public static void SetActiveWindow(IntPtr hWnd)
+        {
+            ShowWindow(hWnd, ShowWindowCommands.SW_SHOW);
+            SetForegroundWindow(hWnd);
+        }
+
+        #endregion
     }
 }