implement async keyboard event sending

Limelight/ViewControllers/CommandManagerViewController.swift

@@ -255,13 +255,28 @@ import UIKit
         print("Sending key-value")
         
         let keyboardCmdStrings = CommandManager.shared.extractKeyStrings(from: cmd.keyboardCmdString)
-        for keyStr in keyboardCmdStrings! {
+        sendKeyDownEventWithDelay(keyboardCmdStrings: keyboardCmdStrings!)
-            LiSendKeyboardEvent(CommandManager.keyMappings[keyStr]!,Int8(KEY_ACTION_DOWN), 0)
+    }
-            print("keycode: \(CommandManager.keyMappings[keyStr] ?? 0xFF)")
+    
-            Thread.sleep(forTimeInterval: 0.05)
+    private func sendKeyDownEventWithDelay(keyboardCmdStrings: [String], delay: TimeInterval = 0.05, index: Int = 0) {
+        guard index < keyboardCmdStrings.count else {
+            for keyStr in keyboardCmdStrings {
+                LiSendKeyboardEvent(CommandManager.keyMappings[keyStr]!,Int8(KEY_ACTION_UP), 0)
+            }
+            return
+        } // 如果已经处理完所有键，释放所有按键
+        
+        let keyCode = CommandManager.keyMappings[keyboardCmdStrings[index]]
+        guard let keyCode = keyCode else {
+            print("No mapping found for \(keyboardCmdStrings[index])")
+            sendKeyDownEventWithDelay(keyboardCmdStrings: keyboardCmdStrings, delay: delay, index: index+1) // 跳过当前键，继续下一个
+            return
         }
-        for keyStr in keyboardCmdStrings! {
+        // 发送当前键的键盘按下事件
-            LiSendKeyboardEvent(CommandManager.keyMappings[keyStr]!,Int8(KEY_ACTION_UP), 0)
+        LiSendKeyboardEvent(keyCode,Int8(KEY_ACTION_DOWN), 0)
+        // 使用 asyncAfter 在指定延迟后发送下一个键的键盘按下事件
+        DispatchQueue.main.asyncAfter(deadline: .now() + delay) {
+            self.sendKeyDownEventWithDelay(keyboardCmdStrings: keyboardCmdStrings, delay: delay, index: index+1) // 跳过当前键，继续下一个
         }
     }
 }